The Vienna Circle and Logical Empiricism: Re-evaluation and Future Perspectives (Vienna Circle Institute Yearbook)

THE VIENNA CIRCLE AND LOGICAL EMPIRICISM

VIENNA CIRCLE INSTITUTE YEARBOOK [2002]

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VIENNA CIRCLE INSTITUTE YEARBOOK [2002] 10 Institut ‘Wiener Kreis’ Society for the Advancement of the Scientific World Conception Series-Editor: Friedrich Stadler University of Vienna, Austria and Director, Institut ‘Wiener Kreis’ Advisory Editorial Board:

Honorary Consulting Editors:

Rudolf Haller, University of Graz, Austria, Coordinator Nancy Cartwright, London School of Economics, UK Robert S. Cohen, Boston University, USA Wilhelm K. Essler, University of Frankfurt/M., Germany Kurt Rudolf Fischer, University of Vienna, Austria Michael Friedman, University of Indiana, Bloomington, USA Peter Galison, Harvard University, USA Adolf Grünbaum, University of Pittsburgh, USA Rainer Hegselmann, University of Bayreuth, Germany Michael Heidelberger, University of Tübingen, Germany Jaakko Hintikka, Boston University, USA Gerald Holton, Harvard University, USA Don Howard, University of Notre Dame, USA Allan S. Janik, University of Innsbruck, Austria Richard Jeffrey, Princeton University, USA Andreas Kamlah, University of Osnabrück, Germany Eckehart Köhler, University of Vienna, Austria Anne J. Kox, University of Amsterdam, The Netherlands Saul A. Kripke, Princeton University, USA Elisabeth Leinfellner, University of Vienna, Austria Werner Leinfellner, Technical University of Vienna, Austria James G. Lennox, University of Pittsburgh, USA Brian McGuinness, University of Siena, Italy Kevin Mulligan, Université de Genève, Switzerland Elisabeth Nemeth, University of Vienna, Austria Julian Nida-Rümelin, University of Göttingen, Germany Helga Nowotny, ETH Zürich, Switzerland Erhard Oeser, University of Vienna, Austria Joëlle Proust, École Polytechnique CREA Paris, France Alan Richardson, University of British Columbia, CDN Peter Schuster, University of Vienna, Austria Jan Šebestik, CNRS Paris, France Karl Sigmund, University of Vienna, Austria Hans Sluga, University of California at Berkeley, USA Elliott Sober, University of Wisconsin, USA Antonia Soulez, Université de Paris 8, France Wolfgang Spohn, University of Konstanz, Germany Christian Thiel, University of Erlangen, Germany Walter Thirring, University of Vienna, Austria Thomas E. Uebel, University of Manchester, UK Georg Winckler, University of Vienna, Austria Ruth Wodak, University of Vienna, Austria Jagiellonian University, Cracow, Poland Anton Zeilinger, University of Vienna, Austria

Kurt E. Baier Francesco Barone † C.G. Hempel † Stephan Körner † Henk Mulder † Arne Naess Paul Neurath † Willard Van Orman Quine † Marx W. Wartofsky †

Review Editor: Michael Stöltzner, University of Bielefeld, Germany

Editorial Work/Layout/Production: Hartwig Jobst Robert Kaller Camilla R. Nielsen Erich Papp Christopher Roth

Editorial Address: Institut ‘Wiener Kreis’ Museumstrasse 5/2/19, A–1070 Wien, Austria Tel.: +431/5261005 (international) or 01/5261005 (national) Fax.: +431/5248859 (international) or 01/5248859 (national) email: [email protected] homepage: http://ivc.philo.at

The titles published in this series are listed at the end of this volume.

THE VIENNA CIRCLE AND LOGICAL EMPIRICISM RE-EVALUATION AND FUTURE PERSPECTIVES

Edited by FRIEDRICH STADLER University of Vienna, and Institute Vienna Circle, Austria

KLUWER ACADEMIC PUBLISHERS NEW YORK, BOSTON, DORDRECHT, LONDON, MOSCOW

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EDITORIAL On the occasion of its anniversary, the Institut Wiener Kreis/Vienna Circle Institute, together with the Zentrum für überfakultäre Forschung/Center for Interdisciplinary Research of the University of Vienna, organized an international symposium on “The Vienna Circle and Logical Empiricism. Re-Evaluation and Future Perspectives of Research and Historiography”. This event was hosted by the Department of Contemporary History at the Campus of the University of Vienna, in Vienna July 12 – 14, 2001. The Institute Vienna Circle (IVC) was founded in 1991 as a non-profit society. It has been supported ever since by the Austrian Ministry of Science and Research and the City of Vienna. The institute is a member of the International Union of the History and Philosophy of Science – Division of Logic, Methodology and Philosophy of Science, and has been working together with the University of Vienna since 1997 on the basis of a co-operation agreement. Since the very outset, the IVC has worked together closely with similar institutes and societies in Austria and abroad, focusing on the promotion, cultivation and dissemination of a scientific philosophy and history and philosophy of science in the tradition and spirit of the Vienna Circle/Logical Empiricism. The Institute’s research activities also include the documentation, application and development of its results. IVC adheres to a pluralist and (post-)enlightened conception of science and philosophy of science that is committed to the democratization of knowledge and science and the critique of all forms of irrationalism, dogmatism, and fundamentalism. To this end, the IVC regularly organizes conferences and lectures in Austria and abroad, edits three book series (in English and German), and maintains a library and archives with materials by, and on, members of the Vienna Circle and associated philosophers as well as scientists. (cf. survey at the IVC’s Website: http://ivc.philo.at). As regards the most recent activities, one should draw attention to the Vienna International Summer University – Scientific World Conceptions, which has been taking place every year (in July) since 2001 at the University Campus. Each summer university has had a different focus on research-related topics: 2001 (Unity and Plurality of Science), 2002 (Mind and Computation), and 2003 (Cosmological and Biological Evolution). Another current activity is our participation in the ongoing ESF-Network on “Historical and Contemporary Perspectives of Philosophy of Science in Europe” , from 2001 to 2003, which is planned to be extended as a follow-up program of ESF. The edition of Moritz Schlick’s papers (Moritz Schlick Edition) is another international research and publication project, which is presently underway with a team of scholars from the University of Graz and the University of Rostock (Germany). The proceedings of the “Third

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International History of Philosophy of Science Conference” (HOPOS 2000) are to be found here in the Vienna Circle Institute Yearbook 9/2001. This Yearbook presents the contributions of invited lecturers as well as a selection of contributed papers of the aforementioned anniversary jubilee conference. It also features work from international research and historiography on Logical Empiricism and its influence, in addition to its further development by renowned scholars and a younger generation of philosophers. We have divided this yearbook papers into thematic chapters that focus on the origins, history and historiography, with such leading figures as Schlick and Reichenbach along with other members of this influential movement. The yearbook also addresses more topical issues such as the unity and plurality of science, contexts of science, epistemology and ethics, and some (long neglected) women of Logical Empiricism. The reception of the Vienna Circle/Logical Empiricism in the Soviet Union and Russia is dealt with in a special concluding report section. As usual, the volume also has a review section on recent publications dealing with scientific philosophy and philosophy of science. In this regard it is important to note that the selected papers on Rudolf Carnap have been published separately in the volume of the IVC series “Vienna Circle Institute Library” established this year. This volume, Language, Truth, and Knowledge, edited by Thomas Bonk, is to appear at the same time as this Yearbook published by Kluwer. Several other invited papers will be part of the forthcoming Cambridge Companion to Logical Empiricism, ed. by Alan Richardson and Thomas Uebel. Last not least let me thank to all who helped make the anniversary conference possible and contributed to the publication of the proceedings in these two volumes: my colleagues Elisabeth Nemeth and Eckehart Koehler as members of the Program Committee, the members of the Local Organizing Committee with Margit (Mischa) Kurka, Daria Mascha, Robert Kaller from the IVC and Marianne Ertl from the Department of Contemporary History. Here I would like to express my sincere gratitude to our financial supporters: the Austrian Ministry of Education, Science and Culture, the City of Vienna (Division of Culture) and the Bank Austria. Finally, I would like to thank our review editor Michael Stöltzner, and Camilla Nielsen, Christopher Roth and Hartwig Jobst, who, together with members of the Advisory Editorial Board, were involved in the production of this Yearbook.

Vienna, October 2002

Friedrich Stadler (University of Vienna, and Vienna Circle Institute)

TABLE OF CONTENTS

A. THE VIENNA CIRCLE AND LOGICAL EMPIRICISM

FRIEDRICH STADLER: What is the Vienna Circle? Some Methodological and Historiographical Answers

I.

XI

ORIGINS AND HISTORY

ARNE NAESS: Pluralism of Tenable World Views

3

PAOLO PARRINI: On the Formation of Logical Empiricism

9

ANITA VON DUHN: Bolzano’s Account of Justification

21

DAVID JALAL HYDER: Kantian Metaphysics and Hertzian Mechanics

35

II.

MORITZ SCHLICK

HUBERT SCHLEICHERT: Moritz Schlick’s Idea of Non-territorial States

49

MASSIMO FERRARI: An Unknown Side of Moritz Schlick’s Intellectual Biography: the Reviews for the “Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie” (1911-1916)

63

HANS JÜRGEN WENDEL: Between Meaning and Demarcation

79

DAGMAR BORCHERS: “Let’s Talk about Flourishing!” – Moritz Schlick and the Non-cognitive Foundation of Virtue Ethics

95

III.

HANS REICHENBACH

CARSTEN KLEIN: Coordination and Convention in Hans Reichenbach’s Philosophy of Space

109

VIII

ROBERT RYNASIEWICZ: Reichenbach’s of Simultaneity in Historical and Philosophical Perspective

IV.

OTHER PROPONENTS

AND

121

PERIPHERY

JUHA MANNINEN: Towards a Physicalistic Attitude

133

WOLFGANG HUEMER: Logical Empiricism and Phenomenology: Felix Kaufmann

151

ARTUR KOTERSKI: Béla von Juhos and the Concept of “Konstatierungen”

163

P AOLO M ANCOSU / M ATHIEU M ARION: Wittgenstein’s Constructivization of Euler’s Proof of the Infinity of Primes

171

GRACIELA DEPIERRIS: Quine’s Historical Argument for Epistemology Naturalized

189

V.

UNITY AND PLURALITY

ELLIOTT SOBER: Two Uses of Unification

205

CHRISTOPHER HITCHCOCK: Unity and Plurality in the Concept of Causation

217

DIEDERICK RAVEN: Edgar Zilsel’s Research Programme: Unity of Science as an Empirical Problem

225

VI.

CONTEXTS OF SCIENCE

GREGOR SCHIEMANN: Criticizing a Difference of Contexts – On Reichenbach’s Distinction between “Context of Discovery” and “Context of Justification”

237

GIORA HON: Contextualizing an Epistemological Issue: the Case of Error in Experiment

253

JUTTA SCHICKORE: The Contexts of Scientific Justification. Some Reflections on the Relation Between Epistemological Contextualism and Philosophy of Science

265

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VII.

EPISTEMOLOGY

DANIEL COHNITZ: Modal Skepticism. Philosophical Thought Experiments and Modal Epistemology

281

F.O. ENGLER: Structure and Heuristic: in Praise of Structural Realism in the Case of Niels Bohr

297

VIII.

ETHICS

UWE CZANIERA: The Neutrality of Meta-Ethics Revisited – How to Draw on Einstein and the Vienna Circle in Developing an Adequate Account of Morals

IX.

313

WOMEN OF LOGICAL EMPIRICISM

DAGMAR BORCHERS: No Woman, no Try? – Else Frenkel-Brunswik and the Project of Integrating Psychoanalysis into the Unity of Science

323

MICHAEL BEANEY: Susan Stebbing on Cambridge and Vienna Analysis

339

NIKOLAY MILKOV: Susan Stebbing’s Criticism of Wittgenstein’s Tractatus

351

A DELHEID H AMACHER - H ERMES : Rose Rand: a Woman in Logic

365

B. GENERAL PART

REPORT – DOCUMENTATION OLESSIA NAZAROVA : Logical Positivism in Russia

381

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REVIEWS

Ernst Mach’s Vienna 1895-1930 or Phenomenalism as Philosophy of Science. Edited by John Blackmore, Ryoichi Itagaki and Setsuko Tanaka. Kluwer Academic Publishers: Dordrecht 2001. (Erik Banks)

389

Herbert Hochberg, The Positivist and the Ontologist. Bergmann, Carnap and Logical Realism, Rodopi: Amsterdam/Atlanta 2001. (Erwin Tegtmeier)

393

Liliana Albertazzi / Dale Jacquette / Roberto Poli (eds.), The School of Alexius Meinong (= Western philosophy series 57), Aldershot et al.: Ashgate, 2001. (Maria Reicher)

397

M. Ferrari / I.-O. Stamatescu (eds.), Symbol and Physical Knowledge. On the Conceptual Structure of Physics, Springer: Berlin 2002. (Thomas Mormann)

401

Uwe Czaniera, Gibt es moralisches Wissen? Die Kognitivismusdebatte in der analytischen Moralphilosophie, Mentis: Paderborn 2001. (Gabriele Mras)

406

ACTIVITIES OF THE INSTITUTE VIENNA CIRCLE

Activities 2002

411

Preview 2003

414

OBITUARY

Eugene T. Gadol (1920-2000) (Friedrich St adler)

417

Index of Names

419

FR I E D R I C H S TADLER

WHAT IS THE VIENNA CIRCLE? SOME METHODOLOGICAL AND HISTORIOGRAPHICAL ANSWERS “What is the Vienna Circle?” is a question which is neither rhetorical nor trivial. It is perhaps an attempt to ‘square the circle’ – which is, meanwhile, mathematically possible, as Karl Menger described as early as 1934.1 This question might be also a problem of how the whole relates logically to the parts or the parts to the whole, which was already addressed by mereology (whole-part theory) according to Stanislaw (1916).2 Of course, we are all familiar with the irritating fact that one and the same phenomenon can be described consistently by more than one theory (underdetermination of a theory by observation). A popular way for beginners to proceed is to check the lexical entries on a concept that might merit further discussion. But is this enough? If we look at the current definitions of the Vienna Circle, we quickly recognize the difficulty of providing a representative description of the circle and of Logical Empiricism in its entirety. Even the autobiographical accounts given since the classical period of the Schlick Circle show a remarkable variance – depending on focus and underlying motivations. The locus classicus is – and remains – the manifesto of 1929 entitled Scientific Conception of the World. The Vienna Circle, published by the Ernst Mach Society and co-authored by Rudolf Carnap, Hans Hahn and Otto Neurath.3 A second milestone in the diffusion of Vienna Circle ideas, especially in the Anglo-Saxon world, was the article written by Herbert Feigl and Albert Blumberg: “Logical Positivism – A New Movement in European Philosophy” (1931) in the Journal of Philosophy. Here, both authors underscored the (anti-Kantian) synthesis of rationalism and empiricism.4 What is so striking about these representative text excerpts? The “scientific world conception” (as opposed to Weltanschauung) is directed against metaphysics as well as philosophy as a discipline in its own right. As an alternative, we can note a tendency towards a (physicalist) unified science that later culminated in an empiricist encyclopedia project and includes the principle of tolerance as applied to logic and scientific languages. Already here, the contours of epistemological options emerge: phenomenalism vs. physicalism, coherence theory vs. correspondence theory of truth, syntax vs. semantics as regards the “logic of science”, ideal vs. normal language as scientific language and, last not least, verification vs. confirmation (or falsification) of empirical statements.

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If one also takes into account that the manifesto represents only one (“left”) wing of the Vienna Circle at the end of the twenties (one simply need recall the negative stance of Schlick under Wittgenstein’s influence), then it becomes abundantly clear that there existed only a limited consensus. Is it possible, even so, to find a sort of basic agreement here – one that unites the members of the Vienna Circle – both the central figures and those on the periphery?5 A simple theoretical framework can be found in the following description: a basic scientific orientation grounded in logical and linguistic analysis, an explanatory and epistemological monism in terms of methodology and research subjects, and finally a sort of fallibilistic epistemology with interdisciplinarity featuring as a program that opposes any sort of foundationalist “system”. First, let me point out that until the end of the Vienna Circle’s existence the tensions between scientific philosophy on the one hand, and empirical science (dualism of philosophy and science) on the other, went unresolved. These differences were most pronounced in the discussions between Moritz Schlick and Otto Neurath.6 We can conclude that neither the autobiographical accounts of contemporaries nor the historical accounts originating shortly after 1945 were able to provide an adequate picture of the Vienna Circle. Moreover, we can only recognize a partial, albeit broad, overlap with Logical Empiricism in general when we take into account the related movements of the Berlin Circle around Hans Reichenbach or the Warsaw Group around Alfred Tarski.7 Here I think that a historical reconstruction is indeed called for, even if it ultimately proves insufficient. Such a reconstruction was already briefly sketched by Gustav Bergmann in his letter to Neurath in 1938:8 Seen in this way, the important scientific movements which until now had their common center of radiation in Vienna – psychoanalysis, the philosophy of the Vienna Circle, and Kelsen’s legal and political philosophy, really belonged together and they determined the specific intellectual atmosphere of the Austria that vanished, just as did, in the artistic sphere, the authors Broch, Canetti and Musil.

The importance of the Vienna Circle as a cultural phenomenon within the context of New Objectivity (Neue Sachlichkeit) is illustrated by contemporary figures and their more or less positive reactions to its program, e.g. the writers Hilde Spiel, Jean Améry, Bertolt Brecht and Robert Musil. 9 But what does present-day research and history have to say about all this? To be sure, the (hidden) history of the reception of Logical Empiricism ranks worldwide as a real success story in the field of history and philosophy of science. Moreover, there has been a remarkable renaissance in research of this area over the past two decades. There seems to be a real interest in the study of the emergence, development and impact of this specifically Central European tradition.10

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As even recent entries on “Vienna Circle” and “Logical Empiricism” present overlapping and incomplete descriptions11, my first suggestion is to attempt a historical and genetic reconstruction within the socio-cultural context, together with a description of individuals and theoretical positions from both a diachronic and synchronic perspective. This means dealing with the multi-facetted phenomenon of the Vienna Circle “from a historical point of view”, which can only be described here in very general terms:12 The new historiography on Logical Empiricism sets in with the rediscovery of Ernst Mach (1838-1916) as a precursor of Gestalt theory, evolutionary epistemology, (possibly radical) constructivism and the modern historically oriented philosophy of science. But already in Mach’s reception of the Vienna Circle one can see not only a certain pluralism of views but also a polarization of the various positions (Mach’s influence on Carnap’s Aufbau / Logical Construction, the critical distancing to “psychologism” in the manifesto, the alternative to the principle of economy in Karl Menger, etc.) 13 Nevertheless, this research program, which was interpreted differently by the Vienna Circle, actually represented a sort of prototype for Logical Empiricism in the interwar years – irrespective of whether one backs the bold claim as to the existence of a “typical Austrian philosophy” (as opposed to German idealism). Accordingly, Richard von Mises described Mach’s impact as follows: “In the transformation from the formal to the material mode of language, Mach’s elements correspond to the protocol sentences.” 14 This, of course, can easily be read as being a building stone of the “neutral monism” as represented by Bertrand Russell. In this context, a number of different studies can be seen as focusing on the impact of neo-Kantianism, Russell and Mach on Carnap’s Aufbau philosophy.15 It is thus not so surprising that, already prior to World War 1, the proto-circle of the later Vienna Circle (the “first Vienna Circle”) began to take shape both organizationally and philosophically. Within a discussion circle (inter alia, with Ph. Frank, Hahn, Neurath, R. v. Mises) at a coffeehouse, traditional “academic philosophy” grew more scientific. The “First Vienna Circle” met regularly as of 1907 to discuss the synthesis of empiricism and symbolic logic as modeled after Mach, Boltzmann and the French conventionalists (Pierre Duhem and Henri Poincaré). This was also regarded as an indirect answer to W.I. Lenin’s polemical remarks against Mach in his book (Materialism and Empirio-criticism. 1909) which remained very influential up to the Velvet Revolution of 1989/90.16 This early phase in the development of Logical Empiricism can also be interpreted as an anti-Cartesian turn in epistemology and philosophy of science, which undermined both the synthetic apriori and the secure foundations of knowledge. In the middle of the “permanent crisis of philosophy” between reform and revolution in society and science, the further development of this “scientific philosophy” had, in any case, been initiated.

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I. Focusing on the center of the Vienna Circle we recognize the following development : with the conflict-laden appointment of the physicist and philosopher Moritz Schlick (1882-1936) to Mach’s chair for natural philosophy of “inductivist sciences” in Vienna in 1922 the heyday of scientific philosophizing in the post World War 1- period was prolonged. Even though Schlick felt committed to an epistemological realism in his main oeuvre General Theory of Knowledge (1918/1925), he began his inaugural lecture with a programmatic allusion to Mach under the sway of the Viennese tradition up to Wittgenstein: “Almost all philosophy is natural philosophy.” 17 Several years thereafter, the intellectual foundations for the formation of the Vienna Circle had been laid: the work of Frege, Russell / Whitehead and Wittgenstein’s Tractatus, together with Duhem’s and Poincaré’s holistic theory of science, paved the way for the emergence of a unique, innovative scientific culture that has remained a subject of international scholarship to this very day and that addresses issues that still have a bearing on modern philosophy of science. In the phase during which the so-called Schlick Circle on Boltzmanngasse became a veritable institution, there was already a pluralism of positions that emerged in the field of tension between Wittgenstein’s Tractatus (1918/22) and Carnap’s Logischer Aufbau der Welt / Logical Construction of the World (1928). But in spite of all discrepancies between Carnap’s ‘rational reconstruction’ and the philosophy of ideal language (Wittgenstein), all those involved came to identify with a philosophical reform movement as opposed to academic “traditional philosophy” (Schulphilosophie according to Philipp Frank). Even the prevailing epistemological options – critical realism (or constructive realism) in Schlick, Feigl, Kraft and later Popper, on the one hand, and phenomenalism / physicalism in Carnap, Neurath, Kaufmann, on the other – could not prevent a reconciliation of rationalism and empiricism. As early as the twenties, a diversity of positions and methods had emerged (a theoretical pluralism which has usually been ignored in the corresponding historiography). The mathematician Karl Menger, who had spent time in Holland, formulated his principle of tolerance regarding the selection of logics and scientific languages (a principle which was only later ascribed to Carnap). He founded an additional platform, namely his influential Mathematisches Kolloquium (“Mathematical Colloquium”), operating in parallel to the Schlick Circle on Boltzmanngasse.18 Long before Quine, he criticized the principle of economy, verificationism and the analytic / synthetic dualism which had become wellknown in uncritical historical accounts as the standard model of Logical Empiricism – an interpretation which was reinforced by Quine’s influential “Two Dogmas of Empiricism”.19 The contacts that were initiated with the Polish logicians and Alfred Tarski (fostering the semantic conception of truth) ultimately

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resulted in a further provocation of the “Wittgenstein group” in the Circle (Schlick, Waismann). But undoubtedly the greatest challenge for the early Vienna Circle was the Tractatus which experienced an uneven and fragmentary reception (as had the manifesto in 1929).20 In sum we can say that, for this formative and non-public phase of the Vienna Circle, certain important components justify the use of the prefix “neo”. A conventionalist understanding of scientific theory, the philosophy of ideal language, and the Hilbert program and theory of relativity (especially Einstein’s 1921 published Geometrie und Erfahrung / Geometry and Experience), as well, became the building blocks for the “turning point in philosophy” proclaimed with great optimism in the first volume of Erkenntnis (Schlick 1930).21 Schlick, Waismann and other members of the Vienna Circle saw knowledge as the correlation of empirical facts with a system of symbols based on formal logic. Such a theoretical innovation was also an intellectual revolution under the sway of modernism, as Carnap formulated so eloquently in his preface to The Logical Construction.22 This radical program, in turn, left an indelible mark on avant-garde art (constructivism associated with Gerd Arntz, the artist of Neurath’s pictorial language), literature as well as architecture (Werkbund and Bauhaus) centering around Ludwig Wittgenstein, Paul Engelmann, Adolf Loos, and Josef Frank, as well as in the context of Neurath’s efforts within the Congrés International d’Architecture Moderne (CIAM). 2 3 Clarity and precision as both ends in themselves and features of scientific philosophy bridged both Wittgenstein’s cultural pessimism and the socio-culturally enlightened impetus of the Vienna Circle. With this convergence of various elements of philosophy of science, the dynamics of theory was accelerated in the phase in which the Vienna Circle made public appearances and expanded its international contacts. The latter development was accompanied by the disintegration and uprooting of Logical Empiricism in the German-speaking world. In this sense, the phenomenon of the Vienna Circle is a prototypical case study on intellectual emigration.24 The gradual liberalization of verificationism and – as Wittgenstein’s influence diminished – the transition from phenomenalism to physicalism (with Carnap and Neurath) was in full swing as already reflected in the publication and internal reception of the 1929 manifesto. The increasingly international orientation of the Vienna Circle had been evident since the late twenties in the contacts with Hans Reichenbach’s Berlin Group, the Warsaw logicians around Alfred Tarski, and the American neo-pragmatist and semiotic movement (Bridgman, Tolman and most notably, Charles Morris).25 By the beginning of the thirties, a research program had emerged with empiricist, physicalist and phenomenalist variants. (e.g., in Felix Kaufmann, the “phenomenologist” of the Vienna Circle, who had been influenced by Husserl, Kelsen and Carnap).26 The themes discussed in Schlick’s circle – such as the principle of tolerance, the disputed foundational problem of empirical science, and the justification and confirmation method with explanation vs. understanding (a variant of the Metho-

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denstreit) – all reflect the seminal methodological debates that were taking place in mathematics / logic (logicism, formalism, Platonism / intuitionism) and in the natural sciences and humanities.27 Undoubtedly, the strongest variant had emerged by 1934 from the Unity of Science movement spearheaded by Neurath, Carnap and later Morris. Their efforts culminated in six well-attended international congresses and the (uncompleted) publication project of the International Encyclopedia of Unified Science.28 This theoretical dynamics and process of differentiation can be illustrated in light of several of the few surviving authentic Vienna Circle documents.29 To all appearances, we are confronted here with two diametrically opposed trends. While the international influence of the Vienna Circle was steadily growing, the group had been systematically marginalized in Austria and Germany starting in the early thirties. The murder of Moritz Schlick and the disgraceful, for the most part anti-semitic, reactions to this, brutally ushered in the process which I have elsewhere described as the “demise of scientific reason”.30 This took place parallel to the general trend at universities, which at the time were increasingly coming under the influence of an growing anti-democratic and racist discourse dominated by clerical-fascist and national socialist forces. This development led to the “Anschluss” which culminated in systematic dismissals, banishment and annihilation. II.

Thus far we have focused mainly on the core of the Vienna Circle – the so-called Schlick Circle – which we can describe as being a matter of applied complexity theory, so to avoid the usual clichés of “positivism” and “neopositivism”. The vitality and productivity of this group that transcended the boundaries of both disciplines and countries was, however, a product of the openness of the logicoempiricist program and the osmosis with the peripheral circles within the sociocultural setting. By way of illustration, I would like to mention just the three most important networks that have been neglected in the pertinent literature or have recurrently prompted highly divergent interpretations:31 Karl Menger’s “Mathematical Colloquium” (“Gödel’s universe”) The Wittgenstein group, including primarily Ludwig Wittgenstein, Moritz Schlick, and Friedrich Waismann The Heinrich Gomperz-Circle, including Karl Popper and Edgar Zilsel, inter alia In this context, it is worth noting that members of the Vienna Circle in addition organized the “Verein Ernst Mach” (Ernst Mach Society) between 1929 to 1934 as a parallel movement serving to popularize scientific philosophy and “The Scientific Conception of the World” as part of the Viennese (“Red Vienna’s”) adult education movement.32 Moreover, Otto Neurath’s “Gesellschafts- und

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Wirtschaftsmuseum in Wien” (Museum of Society and Economics in Vienna, 1925-1934) played an important role with its pictorial statistics (“Wiener Methode der Bildstatistik”) which were developed in exile as the “Isotype” movement as part of the International Encyclopedia of Unified Science project.33 The intellectually fertile ground for all these activities was the remarkably strong participation of Vienna Circle members in the Viennese Adult Education institutions.34 These external perspectives have no bearing on the various interpretations of the transition from Wittgenstein 1 to Wittgenstein 1½ to the late Wittgenstein of Philosophical Investigations where, apart from the anti-Enlightenment thrust, there are remarkable convergences with Neurath’s position in the Encyclopedia of Unified Science. Here I would like to mention the language game conception with its reference to habit, the so-called “scholar’s behavioristics” and “pseudorationalism”, all of which are part of the model of an empirical “orchestration of the sciences”.35 Since the first Vienna Circle, this fallibilistic concept represented for Neurath a basic motive of his critique of every type of unambiguous verification or falsification, as well as of a hierarchical system of sciences with their ultimate foundation. With such a relativistic motive Neurath formulated on a number of different occasions as the well-known “boat metaphor”, which was thus mainly directed at the difficult, but successful newcomer Karl Popper. It was also formulated in a more dramatic way to counter the “semantic turn” of his friend Carnap who stood under the influence of Tarski and Wittgenstein. It was here that the absolutely unbridgeable rifts between philosophical relativism and absolutism became manifest.36 Here it should be mentioned that this controversy of philosophical relativism vs. absolutism continued even after the forced emigration of the Vienna Circle to the U.S, in Philipp Frank’s “Institute for the Unity of Science”; it was this dispute, by the way, that was reformulated with the so-called “Science Wars” in the late 1990s.37 I would also like to make some similar claims with regard to the perhaps more complex and emotion-laden relationship between Karl Popper and the Vienna Circle, since it continues to inform the current debates. This perspective has long been perpetuated in an uncritical way, most notably in Popper’s own accounts, in his teaching and in his research.38 Against this historical background, the relationship between Karl Popper (1902-1994) and the Vienna Circle becomes easier to understand. In his widely-read autobiography Popper presented – and subsequently criticized – the “Popper legend” in the chapter with the not so modest title: “Logical Positivism is dead: Who killed Logical Positivism?” 39 As already mentioned, the Vienna Circle did not represent a static, homogeneous “school” of philosophy, with one dominant figure, one main work and basic dogmas. The reception and appraisal of Popper’s ideas by different members thus very varied considerably: from positive reactions to the Logic of Scientific Discovery (1934) in Carnap, Feigl, Schlick and Frank to the vehement principle

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criticism in Neurath. In his above cited review essay of 1935 Neurath had mainly taken issue with the false search for a privileged system of statements as the paradigm of empirical sciences.40 Popper found this decisive criticism rather “flattering”, although he did not, however, respond to Neurath’s counter-interpretation.41 Neurath had given preference to his meta-theoretical holism and an epistemological relativism as an alternative to the philosophical absolutism that even Popper himself conceded – and this in spite of the fact that, within the Vienna Circle, there were some like Viktor Kraft, Karl Menger, Kurt Gödel and Herbert Feigl who expressed their allegiance to variants of a metaphysical (constructive) realism and intuitionism. Even Schlick, who – apparently for personal reasons – did not invite Popper to his circle on Boltzmanngasse, paid tribute to Popper’s Logic of Scientific Discovery by including it in the series “Schriften zur Wissenschaftlichen Weltanschauung”, which he and Frank edited.42 Thus the meaning criterion of verification, too, became increasingly liberal. From the mid-thirties on it hardly played a role anymore in the Encyclopedia of Unified Science. It had originally been intended more as a pragmatic concept of metaphysics (with Ockham’s razor as an antidote) during Vienna’s inter-war years. (Apart from that period, the history of verificationism was more representative of the status of normal science).43 In the publications and protocols, the Vienna Circle inductivist and hypothetico-deductive methodologies seemed to co-exist. No strict distinction was made between context of justification and context of discovery, which allows us to draw the following conclusions – which are also of general import for the interpretation of Vienna Circle and Logical Empiricism: The history of the development of Logical Empiricist theories since the turn of the century does not allow any clear canonization of a philosophical school in the strict sense, since what we are dealing with is a dynamic between center and periphery. The varying receptions of Wittgenstein, Tarski and Popper have influenced the development of various philosophies of science inspired by rational reconstruction, on the one hand, and by encyclopedic models on the other. Thus, if I were a police commissioner, I would give the following answer to Popper’s rhetorical question: if it’s really true that the patient died, then there is more than one perpetrator, especially from within the circle, both disciples and critics alike. But this, of course, is a completely different story which should be told in another context. III.

Let me come to my tentative conclusions with an illustration of the issue at hand, which is to be elaborated on in forthcoming studies:

WHAT IS THE VIENNA CIRCLE?

THE VIENNA CIRCLE / LOGICAL EMPIRICISM ELEMENTS OF A RE-EVALUATION 1. Methods a) Intradisciplinary: “Scientific Philosophy” b) Interdisciplinary: “Scientific Conception of the World” – “Wissenschaftslogik” – Philosophy of Science – “Wissenschaftstheorie” c) Transdisciplinary: “Encyclopedia of Unified Science” Foundations of the Unity of Science d) Philosophy, Science and Art: Werkbund and Bauhaus External Characteristic: “Coffeehouse Science” (Local and Global Networking) – Science as Culture 2. Scientific Communication a) International: Urban Cultures of Science (Vienna, Berlin, Prague, Warsaw, Cracow, Budapest, Lvov, Copenhagen, Paris, Cambridge /Oxford, London ...) b) Multi-ethnic: mainly enlightened Jewish and many Ethnics/Nationalities c) Multi-lingual: Communication /Publication in German, English, French, Italian, Polish, Turkish Characteristic: “Cultural Exodus” with Disintegration (from the German speaking World) – Internationalization (into the Anglo-Saxon World) 3. (Self-)Organization a) Academic Field: Universities /Academy of Science b) Extra-academic Context: Adult Education and Viennese Cultural Movement of “Spätaufklärung”: Popularisation of “Scientific World Conception” Institutions: ‘Ernst Mach’-Society, Adult Educational Institutions (“Volkshochschulen”), Pictorial Statistics /Isotype with the Social and Economic Museum (Gesellschafts- und Wirtschaftsmuseum in Wien) c) Formal /Informal: Conferences, Lectures /Lecture Series, Seminars, Discussion Groups resp. Books /Book Series, Journals, Working Papers Characteristic: Philosophy of Science as a sort of “Social Epistemology” 4. Sociology of Science and Knowledge a) Men and Women: Else Frenkel-Brunswik, Olga Hahn-Neurath, Marie Jahoda, Marie Reidemeister-Neurath, Olga Taussky-Todd, Rose Rand, Hilde Geiringer-Mises, Susan Stebbing, Janina Hosiasson-Lindenbaum . . . b) Several Generations and Professions: Professors (Distingushed Chairs /Associate/ Assistant), Students and Visiting Scholars from Abroad Characteristic: “Republic of Scholars” (Neurath) Result Uprooting and Alienation from Central Europe! “Americanization” with Mutual Change of Theories

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In addition to the well-known insights that still inform today’s history and philosophy of science (e.g., the explanation and validation of scientific theories; foundations and methods of science between induction and deduction; unity and plurality of science, and so on), I would like to emphasize other topical features of the Vienna Circle which meriting further study. Generally, we see the realization of a common fallibilistic epistemology that points to the hypothetical status of scientific knowledge which is only gradually integrated in everyday experience and language (e.g., common sense). Therefore, the usage of symbolic logic did not contradict a scientific philosophy which is at the same time “a study in human understanding” (Richard von Mises 1951). And I am not reluctant to go back to the classical roots of the Vienna Circle by deliberately using the term ”methodological relativism”.44 First of all, it is a way of philosophizing based on a language-critical attitude and a great amount of problem-oriented, open-ended discussion. This is something experienced personally by Arne Naess, who – as the last living member of the Schlick circle – focuses in this volume on the Vienna Circle’s “thought style” which, in (not only) his opinion, leads to an inherent “pluralism of tenable worldviews”. Secondly, the use of unambiguous language, together with exact methods is certainly a main legacy of the Schlick Circle and those associated with it: it is only given this formal approach that content and positions can be criticized and refuted – a characteristic which most current modern and postmodern philosophies lack. At least the challenge of factual research, and in particular the – admittedly, non-linear – advancement of science (the humanities and natural science) is an essential reason why the tension between science and philosophy (empiricism and rationalism) cannot be resolved definitively. However, the reconciliation of research in different fields of science facilitates permanent reflection and reevaluation of the complex concept called “scientific philosophy”. This reconciliation began in the classical period with its international and interdisciplinary networking, without aiming at one more philosophical dogmatic tradition (which is, by the way, normally characterized by an authoritative head, some leading textbooks and a hierarchical organization covering a limited number of academic fields.) A serious alternative to this (Vienna-Circle oriented) open-minded position can hardly be formulated. I believe that the present volume documents the wide range, pluralism and diversity of the Viennese heritage and message, be it called “scientific philosophy” (as initiated by Schlick), “scientific humanism” (according to Carnap) or a “republic of scholars” (following Neurath), as a guide to a intellectual journey which continues through the present day and on into the future.

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NOTES

1. 2. 3. 4. 5.

6. 7.

8.

9.

10.

11. 12. 13.

14. 15.

Karl Menger, “Ist die Quadratur des Kreises lösbar?” (“Is it Possible to Square the Circle?”), in: Alte Probleme – Neue Lösungen in den exakten Wissenschaften. Fünf Wiener Vorträge, Zweiter Zyklus. Leipzig & Wien 1934, 1-28. Barry Smith, Parts and Moments. Studies in Logic and Formal Ontology. Munich: Philosophia 1982. Peter Simons, Parts. A Study in Ontology. Oxford University Press 1987. An abridged reprint in English translation in: Otto Neurath. Empiricism and Sociology. Ed. by Marie Neurath and Robert S. Cohen. Dordrecht: Reidel 1973, 299-318. Albert Blumberg /Herbert Feigl, “Logical Positivism”, in: Journal of Philosophy 28, 1931, 281296. Members of the inner circle: Gustav Bergmann, Rudolf Carnap, Herbert Feigl, Philipp Frank, Kurt Goedel, Hans Hahn, Olga Hahn-Neurath, Béla Juhos, Felix Kaufmann, Viktor Kraft, Karl Menger, Richard von Mises, Otto Neurath, Rose Rand, Josef Schächter, Moritz Schlick, Olga Taussky-Todd, Friedrich Waismann, Edgar Zilsel. Members of the periphery are: Alfred Jules Ayer, Egon Brunswik, Karl Bühler, Josef Frank, Else Frenkel-Brunswik, Heinrich Gomperz, Carl Gustav Hempel, Eino Kaila, Hans Kelsen, Charles W. Morris, Arne Naess, Karl R. Popper, Willard Van Orman Quine, Frank P. Ramsey, Hans Reichenbach, Kurt Reidemeister, Alfred Tarski, Ludwig Wittgenstein. Regarding the relation of Schlick and Neurath cf.: Rudolf Haller (Ed.), Schlick und Neurath. Ein Symposium. Amsterdam: Rodopi 1982. As to the network with Berlin, Warsaw and Prague: Rudolf Haller / Friedrich Stadler (Eds.), Wien – Berlin – Prag. Der Aufstieg der wissenschaftlichen Philosophie. Wien: Hölder-PichlerTempsky 1993; Lutz Danneberg /Andreas Kamlah /Lothar Schäfer (Hrsg.), Hans Reichenbach und die Berliner Gruppe. Braunschweig-Wiesbaden: Vieweg 1994. Klemens Szaniawski (Ed.), The Vienna Circle and the Lvov-Warsaw School. Dordrecht-Boston-London: Kluwer 1989; Francesco Coniglione, Roberto Poli, Jan Wolenski (Eds.), Polish Scientific Philosophy. The Lvov-Warsaw School. Amsterdam-Atlanta: Rodopi 1993; Katarzyna Kijania-Placek and Jan Wolenski (Eds.), The Lvov-Warsaw School and Contemporary Philosophy. Dordrecht-BostonLondon: Kluwer 1998; Jan Wolenski, Essay in the History of Logic and Logical Philosophy. Cracow: Jagiellonian University Press 1999. Gustav Bergmann, “Memories of the Vienna Circle. Letter to Otto Neurath (1938)”, in: Friedrich Stadler (Ed.), Scientific Philosophy. Origins and Developments. Dordrecht-BostonLondon: Kluwer 1993, 207. Cf. Volker Thurm-Nemeth (Hrsg.), Konstruktion zwischen Werkbund und Bauhaus. Wissenschaft – Architektur – Wiener Kreis. Wien: Holder-Pichler-Tempsky 1998; Wendelin SchmidtDengler (Hrsg.), Fiction in Science - Science in Fiction . Zum Gespräch zwischen Literatur und Wissenschaft. Wien: Hölder-Pichler-Tempsky 1998. To mention only two examples. Ronald Giere and Alan Richardson (Eds.), Origins of Logical Empiricism. Minneapolis: University of Minnesota Press 1996; Gary Hardcastle /Alan Richardson (Eds.), Logical Empiricism in North America. Minneapolis: University of Minnesota Press 2003. Cf. Michael Friedman, “Logical Positivism”, and Friedrich Stadler, ”Vienna Circle”, both in: Routledge Encyclopedia of Philosophy. London-New York 2000. As general reference cf.: Friedrich Stadler, The Vienna Circle. Studies in the Origins, Development, and Influence of Logical Empiricism. Wien-New York: Springer 2001. Cf. Karl Menger, “A Counterpart of Ockham’s Razor”, and ”Geometry and Positivism. A Positivistic Microgeometry”, in: Karl Menger, Selected Papers in Logic and Foundations, Didactics, Economics. Dordrecht-Boston-London: Reidel 1979, 105-135, 225-234. Richard von Mises, Positivism. A Study in Human Understanding. New York: Dover 1951, 99 Alberto Coffa, The Semantic Tradition from Kant to Carnap. To the Vienna Station. Cambridge University Press 1991, Michael Friedman, Rediscovering Logical Positivism. Cambridge Uni-

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16. 17. 18.

19. 20. 21.

22. 23. 24.

25. 26.

27.

28.

29. 30. 31. 32.

33. 34.

35.

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versity Press 1999; Michael Friedman, A Parting of the Ways. Carnap, Cassirer, and Heidegger. Chicago and La Salle, Ill.: Open Court 2000; Alan W. Richardson, Carnap’s Construction of the World. The Aufbau and the Emergence of Logical Empiricism. Cambridge University Press 1998. Thomas Uebel, Vernunftkritik und Wissenschaft: Otto Neurath und der Erste Wiener Kreis. Wien-New York: Springer 2000. Cited in: Stadler, The Vienna Circle, op.cit., 196. Karl Menger, Ergebnisse eines Mathematischen Kolloquiums. Ed. by E. Dierker and K. Sigmund. Wien-New York: Springer 1998; Karl Menger, Reminiscences of the Vienna Circle and the Mathematical Colloquium. Ed. by Louise Golland, Brian McGuinness and Abe Sklar. Dordrecht-Boston-London: Kluwer 1994. First Publication: Willard Van Orman Quine, ”Two Dogmas of Empiricism”, in: Philosophical Review 60, 1951,20-43. Jan Wolenski and Eckehart Köhler (Eds.), Alfred Tarski and the Vienna Circle. Austro-Polish Connections in Logical Empiricism. Dordrecht-Boston-London: Kluwer 1999. Moritz Schlick, “The Turning Point in Philosophy” (1930), in: Schlick, Philosophical Papers. Ed by H.Mulder and Barbara F.B. van der Velde-Schlick. Dordrecht-Boston-London: Reidel 1979, 154-160. Rudolf Carnap, The Logical Structure of the World. Berkeley and Los Angeles: University of California Press 1967. Translated by Rolf George. Cf.: Elisabeth Nemeth and Friedrich Stadler (Eds.), Encyclopedia and Utopia. The Life and Work of Otto Neurath (1882-1945). Dordrecht-Boston-London: Kluwer 1996. Cf. Friedrich Stadler, “Transfer and Transformation of Logical Empiricism”, in: Giere/ Richardson (Eds.), op.cit, and “The Wiener Kreis in Great Britain: Emigration and Interaction in the Philosophy of Science”, in: Edward Timms / Jon Hughes (Eds.), Intellectual Migration and Cultural Transformation. Wien-New York: Springer 2002. Cf. Gerald Holton, “From the Vienna Circle to the Harvard Square”, in: Stadler, Scientific Philosophy op.cit., 47-73. Friedrich Stadler (Hrsg.), Phänomenologie und Logischer Empirismus. Zentenarium Felix Kaufmann. Wien-New York: Springer 1997; Clemens Jabloner / Friedrich Stadler (Eds.), Logischer Empirismus und Reine Rechtslehre. Beziehungen zwischen dem Wiener Kreis und der Hans Kelsen-Schule. Wien-New York: Springer 2001. Cf. The Foundational Debate. Complexity and Constructivity in Mathematics and Physics. Ed. by Werner DePauli-Schimanovich, Eckehart Köhler and Friedrich Stadler. Dordrecht-BostonLondon: Kluwer 1995. Otto Neurath / Rudolf Carnap / Charles Morris (Eds.), Foundations of the Unity of Science. Towards an International Encyclopedia of Unified Science. 2 Volumes. The University of Chicago Press: Chicago and London 1970f. Cf. the protocols of the Schlick Circle and the theses of the Vienna Circle as reported by Rose Rand in: Stadler, The Vienna Circle, op.cit., ch. 7.1. Friedrich Stadler/Peter Weibel (Eds.), The Cultural Exodus from Austria / Vertreibung der Vernunft. Wien-New York: Springer 1995. A reconstruction in detail in: Stadler, The Vienna Circle, op.cit., chapters 8-10. Stadler, ibid., ch. 7.2, and John Blackmore (Ed.), Ernst Mach – A Deeper Look. Documents and Perspectives. Dordrecht-Boston-London: Kluwer 1992: John Blackmore, Ryoichi Itagaki, Setsuko Tanaka (Eds.), Ernst Mach’s Vienna 1895-1930 or Phenomenalism as Philosophy of Science. Dordrecht-Boston-London: Kluwer 2001. Nemeth /Stadler (eds.), Encyclopedia and Utopia, op.cit., section III. The following members lectured and instructed courses in several institutions (“Volkshochschulen”): Rudolf Carnap, Herbert Feigl, Philipp Frank, Hans Hahn, Felix Kaufmann, Viktor Kraft, Otto Neurath, Moritz Schlick, Friedrich Waismann, and Edgar Zilsel. Otto Neurath, “The Orchestration of the Sciences by the Encyclopedism of Logical Empiricism” (1946), in: Neurath, Philosophical Papers 1913-1946. Ed. by Robert S. Cohen and Marie Neurath. Dordrecht-Boston-Lancaster: Reidel 1983, 230-242.

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36. Otto Neurath, “Pseudorationalism of Falsification”, in: ibid., 121-131. From an Popperian point of view cf.: Malachi H. Hacohen, Karl Popper – The Formative Years. 1902-1945. Politics and Philosophy in Interwar Vienna. Cambridge University Press 2000. 37. Cf. Friedrich Stadler, “Challenging the Dogma of the Ahistorical Philosophy of Science: The Case of Relativism”, in: Jutta Schickore / Friedrich Steinle (Eds.), Revisiting Discovery and Justification. Berlin: Max Plack Institute for the History of Science 2002. (Preprint 211). 38. Regarding a contextual reconstruction of Heinrich Gomperz, Karl Popper and the Vienna Circle: Stadler, The Vienna Circle, op.cit, ch. 10, and Martin Seiler / Friedrich Stadler (Hrsg.), Heinrich Gomperz, Karl Popper und die österreichische Philosophie. Amsterdam-Atlanta: Rodopi 1994. 39. In: The Philosophy of Karl Popper. Ed. by P.A. Schilpp. La Salle, Ill.: Open Court 1974, 3-181. 40. By the way, popper never replied to this decisive criticism, cf. Stadler, The Vienna Circle, op.cit., Interview with Sir Karl Popper (1991), 474-497. 41. Ibid., 487. 42. Letter Schlick to Frank, June 9, 1933. Vienna Circle Archives, Haarlem, Holland. 43. Cf. C.J. Misak, Veriflcationism. Its History and Prospects. London-New York: Routledge 1995. 44. Philipp Frank, Relativity – A Richer Truth. Foreword by Albert Einstein. Boston: 1950.

Vienna Circle Institute Museumstraße 5/2/19 A-1070 Vienna Austria [email protected]

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I.

ORIGINS AND HISTORY

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ARNE NAESS

PLURALISM OF TENABLE WORLD VIEWS I shall try to outline a philosophical point which I think might be acceptable from a combined logical and empirical point of view. From the world view (wissenschaftliche Weltauffassung) to the manifoldness (Mannigfaltigkeit) of tenable world views. In the following, I consider humans as not insignificant parts of the world. Different views about humanity therefore imply different world views. A second premise I assume increases the manifold of which I speak. By “scientific” I do not here mean something like “implied by science” but a weaker contention: “compatible with science”. What about religious views if a weaker contention is adopted? The formidable development of Christian theology since Søren Kierkegaard has reduced earlier tendencies to assume that there must be a conflict between Christian and scientific general views. The number of what were called Christian dogmas is reduced. Here I shall only suggest that this development – plus the considerable increase in the number of people who favor a sort of Buddhism – increases compatibility. But I find it premature to take up the many implied relevant questions. The only remark I tentatively make is that those questions suggest a possible scientific acceptability of certain world views which have a strong religious flavour. Logical empiricists, as I understood their Weltauffassung, suggested a view of the world derivable from scientific knowledge. Because scientific knowledge – apart from mathematics and logic – was clearly considered hypothetical, the status of a definite articulation of such a view would, by necessity, be rather hypothetical. One way to delimit the use of the term “science” is by assuming that it only comprises the natural sciences. In what follows, I include a large part of the humanities. Historical research is scientific in the fairly large sense to which I subscribe. A world view that clearly negates results of historical research is not a world view compatible with science. Historiography, the streamlined accounts of enormously complicated happenings, need not be compatible with scientific method. Two mutually incompatible accounts of a revolution may both be excellent, but not part of a science. Suppose somebody asks you: “What is your world view?”, suggesting that he or she would write an article or a book describing (and criticising?) it. It is fairly clear that what would be considered an adequate answer would have to take into consideration that person’s value priorities. We should demand of a descripton of 3 F. Stadler (ed.), The Vienna Circle and Logical Empiricism: Re-evaluation and Future Perspectives, 3–7. © 2003 Kluwer Academic Publishers. Printed in the Netherlands.

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a world view actually held by a human being that it take into account his or her value priorities. The logical empiricists took this seriously. Especially when political issues were being discussed, they outlined value priority views which were simply “dangerous”. That is, the increasingly powerful national socialist movement made public assertions of opposite views likely to result in repressive attacks, sometimes even in incarceration in a concentration camp. The pertinent answer to the formidable question “What is your world view?” will assume different forms: if you and your family are politically repressed, or if you are engaged in a dangerous fight against oppressors, your world will be narrower. If you live in a peaceful country like Norway, and you are without severe political or personal problems, perhaps only then are you likely to take very broad questions such as those of cosmology seriously. Incidentally, descriptions of what is going on in the cosmos by professional cosmologists tend to be talk about vast, unimaginable explosions within vast areas of time. This may not give rise to dark or pessimistic, tenable world views. The formidable power of the Catholic Church in Vienna was felt in everyday life. Traffic came to a halt when some religious procession required considerable space in the streets. I remember such an occasion in which traffic came to a complete standstill because a ‘relic’, a piece of bone that might possibly have belonged to Christ, was triumphantly paraded through the city. At least one of the logical empiricists, Otto Neurath, had respect for and perhaps was jealous of, the power of the Church. He admired certain trends within the philosophical traditions of Catholicism. He insisted that especially Thomas Aquinas, but also other theologians developed their ideas on a remarkably high logical level. For certain axioms, they derived conclusions in a logically safe way. It was not by chance that Otto Neurath again and again warned against what he called excessive respect for mathematics and logic: “Logic? Leave it to the Catholic experts!”. He himself had great competence in logic and the history of logic, but having been active in politics – not without serious consequences (prison) – he warned against trying to formulate logical empiricist political views on a high logical level. These views were, as could be expected in the 1930s, mostly socialist and sometimes Marxist. But back to the question of limits to the diversity of world views compatible with the results of scientific research. More than most philosophers, I admire and cherish research rather than science. The endlessness of research, and the short life of definite scientific theories compared, for instance, to ethical norms, are for me a source of great admiration. It has reminded me of climbing: always risky to some extent, but manageable and mostly open to well-founded trust. I recommended in 1935 that the terms “antimetaphysical” (or even “ametaphysical”) be left out of the formulations of basic characteristics of logical empiricism. Rudolf Carnap’s view that philosophy in the future would essentially consist in the elaboration of the logical syntax of language, I found deplorable. I recommended that “research attitude” should be used as a central expression and slogan, rather than “scientific world view”. Our views should not be incompatible with a

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consistent research attitude. (After all, there are innumerable questions we pose which are not even very thinly covered by painstaking research.) There is not much vitally relevant science to point to. Propaganda for more such research, and a more consistent research attitude, are both essential. The metaphysics of Spinoza includes a definition of freedom and of free choice. Very roughly, a decision is free according to him when taken under no external pressure whatsoever. But “God” (Deus) is defined in such a way that it does not invite research. If we start with the last part of the Ethics, and not the formidable first part, we are open for research and redefinition of terms. This, in turn, facilitates an intense research attitude in relation to metaphysical texts in general. From the last – the fifth – part, we may proceed to the broad, fourth part. Every point there has a practical, a life import. In short, it is possible to maintain a research attitude, even when interpreting and applying the “dense” metaphysics of Spinoza. When I was staying in Carnap’s home in California, this was one of the themes of our daily discussion. On entering the Schlick seminar in Vienna in 1934, I presented myself as a kind of Spinozist. Spinoza enjoyed, of course, a high standing among the seminar members, but philosophy the way Spinoza practised it was of course fully, totally, decisively a matter of the past. So it was considered touching and in a way, admirable, to be a kind of Spinozist, but philosophically it was centuries too late. What I am driving at is a complete acceptance of the kind of metaphysical formulations of a philosopher like Spinoza. That is, acceptance of their meaningfulness. But as for the kind of understandable contemporary articulations which would today be nearest to the meaning of his formulations is an open question. Different sets of answers would play a role in outlining different Spinozist world views. They would present examples of “scientifically” acceptable, mutually more or less incompatible world views. Studying Immanuel Kant’s texts, we may arrive at similar, or at least analogous, conclusions. Considering the great number of mutually incompatible nineteenth century and later Kant interpretations, we might point to the possibility of a variety of modern Kantian world views. What about old Chinese and Indian philosophies? We may tentatively interpret the texts so as to make them relevant to the questions of scientific compatibility. The pervasive relevance of yoga in Indian philosophy has been studied extensively in the West as a practice, a strangely close combination of a seemingly abstruse and vague philosophy with very definite, clearly described practices. As an example of basic philosophical terms rather different from western ones, I would like to concentrate on “emptiness”, “sunyata” in Sanskrit. At an East-West international philosophical congress, an Indian participant left his chair in a quiet way and crawled under the table. When asked closely later what he meant by this, he tried to make us understand that his movement was relevant and philosophically understandable within the Indian yoga tradition he belonged to.

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What I am suggesting is the acceptance of the existence of a variety of different world views, all compatible with science. But it should also be added that the research centering on this diversity reveals the very serious difficulty of finding a vocabulary or a terminology that, at least not entirely superficially, describes the cognitive content of each of the different world views. The deeper the differences, the more difficult it is to find a terminology that makes a survey possible. Why is the richness of world views today perhaps more important for the future of humanity than ever before? Because, as I see it, vast globalization is inevitable. What by many people is believed to be – on the whole – a great advantage, might turn into a calamity in my view. War becomes more unlikely because war within a closed system of globalised economic liberalism will rightly be seen as a threat to that very economic system. But the likelihood of people and societies with a pronounced tendency to maintain clearly different world views decreases. The intensity of human interaction crossing all borders may foster a certain level of Gleichschaltung, a tendency for a decrease in the diversity of world views realised and acted upon at any definite time. In the 1930s there was in Europe a decrease in the diversity of world views because of the intense focus on (Soviet) communism versus anti-communism, and Nazism versus anti-Nazism. Today, other factors tend to limit diversity. The globalization of technology and perhaps the intensification of interaction through e-mail and chatting on the Internet? In 1934 and 1935 it seemed paradoxical to me that logical empiricists stressed the term “empiricism”. They tended to reject the idea that painstaking empirical research could be a genuine part of philosophical inquiries. Philosophy as logical syntax of language did not, according to Carnap, need anything of the kind. It needed theoretical clarification, but he did not put up any list of questions of an empirical kind which had to be answered in order to discover the logical syntax of actual spoken languages. There are extremely different languages – so different that the translation of one into another is a highly creative job very different from translations within the scope of English, French and German. The definite and complete rejection by Carnap of Heidegger’s sentence “Das Nichts nichtet” did not, for Carnap, need substantial empirical support. I mean empirical research. Movements comparable to logical empiricism might invest quite a deep concern to avoid unnecessary rejections. Let me for a moment consider a special movement. Within the ecological movement there are groups often characterized as “doomsday prophets”. They are, as I see it, generally criticised in an unnecessarily harsh way. I propose that we say something of this kind: “Yes, if present trends of unecological policies continue long enough, catastrophes are likely to occur, but we don’t have reason to believe that such polices will actually persist long enough to make catastrophes likely.” The opinion of Moritz Schlick and certain other logical empiricists that philosophy of the traditional kind was dead or would soon die did not destroy the importance of what the traditionalists were saying. The same applies to the

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doomsday prophets. Much of what they say is of some interest. It is only their radical negative predictions that need not be taken very seriously. Could the study of the remarkable influence of logical empiricism in the thirties help to instigate a comparable movement today? We talk about a global “green” movement. Within that movement a diversity of world views is powerfully presented. One is that of favoring “a rich life with simple means”. It presumes that people have fairly clear value priorities. Instead of mathematics and formal logic being studied with special intensity, there would be studies of “life quality”, how one feels about oneself and the world. Comparative studies of what makes people feel well, of course, including the study of feeling well in the economically poor countries, are relevant. Logical empiricism was acutely controversial from the first moment. To the extent that such a reception is inevitable, it is highly suspicious if a movement does not at least start as a controversial phenomenon. The green movement called “deep ecology” was for many years highly controversial. But at a fairly recent international congress in Melbourne, Australia, it appeared to be fairly, if not totally, uncontroversial. At the same conference, the following question became more pertinent: “But what can be done to change politics in a green direction?” That question refers to problems not directly attacked by the deep ecology movement as such. Logical empiricists certainly were fully aware of the necessity of being politically active. Are they comparably healthy movements today? I don’t think there are any, but it is important for many of us to try to influence movements we wish well to reach the high level of creative dialogue and sober mutual respect in spite of differences of opinion which characterized the logical empirical movement.

Centre for Development and Environment University of Oslo, Box 1116 Blindern N-0317 Oslo Norway [email protected]

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PAOLO PARRINI

ON THE FORMATION OF LOGICAL EMPIRICISM

1.

THE STATUS QUAESTIONIS

During the discussion between D. Howard and T. Oberdan at the 1991 Conference, organized in Konstanz for the centenary of Carnap’s and Reichenbach’s birth, the following question was posed: is it possible to see Schlick’s Allgemeine Erkenntnislehre as an anticipation of the theses that later characterized the Vienna Circle (which was formed around Schlick himself) and that were formulated by its members taking into consideration also Russell’s and Wittgenstein’s ideas?1 This question refers to the existence of a first Vienna Circle and the nature of the relationship between this first group and the ‘real’ Vienna Circle. T. Uebel has re-examined this second question in a paper recently presented at the Florentine conference on Logical Empiricism (1999). Looking at it from an interesting perspective, he aims at singling out the characteristics of Logical Empiricism as a distinctive school of philosophical thought. More precisely, he asks himself whether it was simply another version of neo-Kantian philosophy and, if not, what other elements were present. In order to provide an answer, he discusses again the relationship between the Austrian and German-Kantian components underlying the movement and links his paper to the recent debate on the distinction between analytic and continental philosophy. According to Uebel, “it was the co-operation of the members” of the “early circle of philosophically minded Austrian scientists – the mathematician Hans Hahn, the physicist Philipp Frank and the economist Otto Neurath – with the scientifically trained German philosophers Moritz Schlick and Rudolf Carnap that accounted for the distinctive force of Viennese Logical Empiricism”. This can be clearly seen – he states – when we look at the positions taken by Schlick in the Allgemeine Erkenntnislehre (1918 1 , 19252). Uebel explicitly says, though, that in his reconstruction he does not take into consideration the Berlin strand of Logical Empiricism2. I intend here to discuss this very same set of questions showing how the analysis of the evolution of the ideas of the main member of the Berlin Circle – H. Reichenbach – and thus of the more German branch of the neo-empiricist movement, can bring to light some interesting elements. Important indications can be found in the philosophy of geometry he developed in Philosophie der 9 F. Stadler (ed.). The Vienna Circle and Logical Empiricism: Re-evaluation and Future Perspectives, 9–20. © 2003 Kluwer Academic Publishers. Printed in the Netherlands.

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Raum-Zeit-Lehre (1928). More precisely, I will try to show that the analysis of the debate on Kantism that divided Reichenbach and Schlick in the early 1920s at the time of their discussion on the theory of relativity, and the analysis of Reichenbach’s subsequent change of perspective on the nature of “coordinative principles” are enlightening on two relevant points that are closely related to Howard’s, Oberdan’s and Uebel’s above-mentioned interpretations: (i) the relationship between Kantism and Conventionalism within Logical Empiricism; (ii) the role played by typically neo-empiricistic ideas such as the verification principle and the thesis of the tautological nature of logic – ideas which are more of an ‘analytic’ than of a ‘continental’ nature – regarding the possibility of using French Conventionalism in a strictly neo-empiricistic sense and not in a neoKantian one. My final goal is to show that we cannot understand Logical Empiricism’s development if, as traditional interpretations did, we focus our attention only on the positions developed under the influence of Russell’s and Wittgenstein’s ideas, thereby ignoring the Kantian and Conventionalist heritage of the movement. On the other hand, in order to show the importance of these components, we must not overlook the ‘other half of the apple’: the conceptual reorganisation brought about by a reconsideration of some old problems in light of the new theoretical approach linked to the coming to the fore of some theses (verification principle and linguistic theory of the a priori) which are the consequence of the impact of Russell’s and Wittgenstein’s ideas interpreted from an empiricistic perspective. 2. SCHLICK’S CRITICISM OF IMMANENCE PHILOSOPHIES AND REICHENBACH’S CONCEPTION OF THE OBJECT OF KNOWLEDGE

To illustrate my point, I will first focus on the criticism Schlick made in the first edition of Allgemeine Erkenntnislehre (1918) against immanence philosophies, in particular Schuppe’s immanentism, on the basis of his conception of knowledge intended as coordination. In criticizing Schuppe’s immanentism, Schlick says that it is “quite clear that thought, in the sense relevant to knowledge, signifies nothing but the designation of objects. But that an object is not produced by our giving it a designation – indeed, it is independent of it and can exist without our correlating some sign or representation with it – is all contained in the very concept of designation. The above fallacy would never have been committed if the two meanings of the word ‘thought’ had been kept apart by assigning different terms to them” 3. In other words, Schlick considers his conception of ‘knowledge’ to be antithetic to Schuppe’s, because it encompasses the idea that the sense of ‘to think’ inherent to knowledge means only “to designate objects” and that it has nothing to do with any kind of dependence of the objects on the thought designating them. As we know, in the Allgemeine Erkenntnislehre these objects are charac-

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terized as transcendent objects and even called by the Kantian expression “Dinge an sich” (things-in-themselves). In Reichenbach’s conception, which differs from Schlick’s, the equation of the process of ‘knowing’ to a process of unique coordination could be used to explain why the object of knowledge, constituting some sort of non-metaphysical ‘transcendence’, remains nevertheless ‘immanent’ with respect to the presuppositions of the cognitive process. In his 1920 essay Relativitätstheorie und Erkenntnis Apriori, Reichenbach used the characterization of knowledge elaborated by Schlick partly to reject and partly to accept Kant’s conception of the a priori. Here the coordinative conventions mentioned by Schlick are treated as “constitutive principles”. They are introduced and characterized in contrast to particular laws by calling into question their constitutive value with respect to the objects of knowledge: in “contrast to particular laws” (or “axioms of connection” [Verknüpfungsaxiome]), these constitutive principles (or “coordinating principles”, “axioms of coordination” [Zuordnungsaxiome]), “do not say what is known in the individual case, but how knowledge is obtained; they define the knowable, [...] they show the order rules according to which knowledge is obtained and indicate the conditions the logical satisfaction of which leads to knowledge.” For Reichenbach, in the process of knowing, one of the two sides of knowledge – ‘the real’ – “is defined by coordination with the equations”. The object of knowledge thus constitutes itself in a way which is immanent with respect to the coordination principles. Its transcendence is due to the fact (devoid of any metaphysical connotations) that it is susceptible to a potentially unlimited number of empirical determinations4. In Schlick’s conception of knowledge, the elements of one of the ends of the cognitive connection (concepts and judgments) are coordinated with the elements of the other end (objects and facts) by means of the introduction of suitable connections of a definitional and conventional nature. It is by means of these kinds of connections (usual, concrete, implicit and coordinative conventions) that we make the association between the apparatus of symbols and the entities (objects and facts) that concepts and judgements have to designate. What remains valid in Reichenbach is Schlick’s idea of knowledge as coordination or designation, and truth as unique coordination or designation. The elements of the two ends of the coordination, though, are not conceived as preexisting to the coordination itself: coordination connections have a function in the constitution of the objects of knowledge. Evidently, even though they both consider as valid the coordinative or designative conception of knowledge, these two ways of looking at the cognitive process are profoundly different. This difference affects and is made evident by Schlick’s and Reichenbach’s attitudes towards Kant’s theory of synthetic a priori judgements.

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3. THE DISAGREEMENT BETWEEN SCHLICK AND REICHENBACH ON KANTIAN PHILOSOPHY AND CONVENTIONALISM

This divergence of opinions on the object of knowledge refers back to their wellknown disagreement regarding the way in which they rejected Kantian synthetic a priori judgements. Reichenbach distinguished between two different meanings of the concept of a priori: 1) a priori in the sense of “‘necessarily true’ or ‘true for all times’”, and thus of absolutely independent of experience; 2) a priori, in the sense of “‘constituting the concept of object’”, that is, the principle that forms the object of scientific knowledge, more specifically of physics. The theory of relativity shows the indefensibility of the first notion of a priori, but not of the second5. On the contrary, since the years of the first edition of Allgemeine Erkenntnislehre, Schlick did not seem willing to concede anything to Kantianism. On this point he criticizes both Cassirer and Reichenbach, and maintains that the essential characteristic of the Kantian synthetic a priori is the connection, in the very same concept, between the apodeictic certainty and the constitutive value. Consequently, he does not make a distinction between the two meanings of Kantian synthetic a priori, thereby avoiding its adoption in any of its two senses. The more general and abstract component of scientific knowledge should be assimilated not in Kantian constitutive principles (even if devoid of any apodeictic validity) but to very general hypotheses or to conventions as defined by Poincaré6. And if we ask ourselves what ‘convention’ in Poincaré’s sense means, the only sensible answer we can give is that we must be talking about conventions of a linguistic-definitional nature – conventions the task of which consists in establishing scientific language regarding the formulation of both scientific facts and laws. Poincaré explicitly states this thesis in his pages on geometry and in his polemic against Eduard Le Roy’s radical conventionalism (“nominalism”).7 The terms of agreement and disagreement between Schlick and Reichenbach in the 1920s are now clear. They both took as their starting point a general interpretation of knowledge intended as coordination and the negation of Kant’s theory of the synthetic a priori. Within this very same framework, though, Schlick states that in order to understand cognitive coordination we need admit only the existence of linguistic conventions, in full conformity with his idea that in the cognitive process we have a designation of objects and facts by means of suitable concepts and judgements on the basis of previously fixed conventions. According to Reichenbach cognitive coordination can be understood only if we admit the existence of coordination principles that constitute the objects of knowledge and that, as such, have to be assimilated to Kant’s synthetic a priori principles in all features excepting that of their apodeictic validity.

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The terms of their disagreement were thus as profound and strong as the terms of their agreement. Despite this, in the early 1920s both authors gradually developed a more similar perspective that aimed especially at defending – in contrast to Kant and Cassirer’s neo-Kantianism – ‘the contingent nature of the cognitive synthesis’, in other words, the idea – related to the thesis of the independence of perception of reason – that the very same possibility of coordinating concepts to experiences and obtaining a unique coordination (truth) depends on experience. This possibility has been proven by now, but we cannot demonstrate a priori its necessity8. All this is indicated by the numerous letters they exchanged on this topic between September and December 1920, as well as by the conclusive comment on their discussion made by Reichenbach in “Der gegenwätige Stand der Relativitätsdiskussion”.9

4. THE ANALYSIS OF GEOMETRY AND CONGRUENCE IN “PHILOSOPHIE DER RAUM-ZEIT-LEHRE”

I think that the disagreement between Schlick and Reichenbach was not of an exclusively terminological nature. It was more related to the question of whether it is possible to understand the cognitive process by taking recourse to only two components, experience and linguistic conventions (including coordinative conventions), or whether besides these two we also have to admit some presuppositions of a synthetic nature constitutive not only of science’s language (such as the more strictly linguistic ones) but also of the objects of knowledge. Disregarding our judgement on this matter from the theoretical point of view, from a historical point of view we have to underline that in the years following 1922, Reichenbach changed his original position and ended up embracing the one defended by Schlick. Even in his 1924 work Axiomatik der relativistischen Raum-Zeit-Lehre, Reichenbach adopts Schlick’s perspective and terminology: he refers to implicit and explicit definitions (impliziten and expliziten Definitionen), but instead of speaking of constitutive principles or coordination principles he speaks of coordinative definitions [Zuordnungsdefinitionen], seen in contraposition with conceptual definitions [Begriffsdefinitionen] 10. Moreover, he already sees the problem of the choice of the best set of definitions as having “nothing to do with the truth of a theory”. He presents it in connection with “descriptive simplicity”, viewed in contrast to “inductive simplicity” as “a principle of probability” containing “an important assertion about the physical world” 11. In Axiomatik der relativistischen Raum-Zeit-Lehre he still considers the distinction between the different components (conventional and empirical) of scientific theories as one of the main tasks of epistemological analysis: some of these components, though, are no longer seen as constitutive principles, but simply as conventions that have the value of coordinative definitions.

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A similar position is expressed in Philosophie der Raum-Zeit-Lehre (1928). While discussing the problem of the empirical determination of geometry, Reichenbach underlines the existence of a subjective arbitrary component in the scientific cognitive process without which – he explicitly states – objectivity cannot be attained. Now, though, he speaks of Zuordnungsdefinitionen, and these coordinative definitions are described in semantic-linguistic terms. If we change the coordinative definitions, we no longer constitute a different object. We simply give empirically equivalent descriptions – for example, different geometrical descriptions of the physical world – that differ only for the language in which they are formulated 12. What can we say about Reichenbach’s relevant change of perspective? What prompted him to move closer and closer to Schlick’s position according to which we only have either hypotheses or conventions? Until now, I have found no indicative references in either Reichenbach’s works or in the archive material 13 . So, even allowing that future studies might bring to light new documents, it seems to me that the only possible conclusion here is that neither Schlick, Reichenbach or Carnap felt the need to say even a few words about Reichenbach’s change of perspective. Personally, I don’t know how to interpret this silence. Is it a meaningful event or simply a twist of fate not worth any further consideration? An analysis of Reichenbach’s text, though, allows us, I think, to advance a hypothesis and here we come to the main point of my paper: the re-evaluation of the role played by Russell’s and Wittgenstein’s ideas in the formation of what was considered the standard doctrine of Logical Empiricism, the way in which Logical Empiricism was viewed for a number of decades, and Quine’s criticism thereof in his famous “Two Dogmas of Empiricism”. This possible answer can be explained on the basis of the fact that Reichenbach’s argumentation about the problem of empirical determination of physical geometry, and the necessity to take recourse to a coordinative definition of congruence, are perfectly in tune with the ideas elaborated by the Logical Empiricists of the Vienna and Berlin Circles on the nature of logic and meaning. I am referring here to the ideas that more or less freely, and more or less legitimately, referred back to Russell’s philosophy of logical atomism and Wittgenstein’s Tractatus logico-philosophicus, in other words to that type of philosophy that traditional interpretations have considered, along with Mach’s thought, to be one of the main origins of Logical Empiricism as it appeared on the philosophical scene between the late 1920s and the early 1930s. These philosophical ideas are the following: (i) the subdivision of statements in simple (elementary, atomic) and complex, and the dependency of the value of truth of the former on specific experiences associated to them; (ii) the tautological nature of some complex statements, in other words, the fact that they are devoid of any empirical-factual content; (iii) the argument expressed by proposition 4.024 of the Tractatus (“To understand a sentence means to know what the case is when it is true”), understood by Logical Empiricists as stating (contrary

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to what Wittgenstein wanted to say) that understanding a statement means understanding the conditions of its empirical verification. This formulation amounts to the verification principle, according to which the meaning of a statement is its means of empirical verification and implying that all those statements that cannot be verified empirically have to be considered as devoid of meaning. As I have already shown14, both Reichenbach’s final position and its underlying argumentation are far closer to Poincaré’s geometric conventionalism than what Reichenbach admitted himself. What is relevant for the purposes of my paper, though, is that Reichenbach’s argumentation (like that already presented by Poincaré) is explicitly posited in terms of meaning and lends itself to reconstruction taking into consideration the above-mentioned typically neo-empirical ideas. Reichenbach mentions neither Russell’s nor Wittgenstein’s names; he does not even quote the verification principle or the thesis of the tautological character – and thus empirical and factual vacuity – of certain statements. Nevertheless, when explaining why a certain assumption (the coordinative definition of congruence expressed through the elimination of universal forces) has to be seen as a definition without justifying his change of perspective with respect to the years when he considered similar assumptions as being constitutive principles analogous to Kant’s synthetic a priori principles, he uses the concept of meaning and expresses his arguments by means of verificational terms and ideas. In Philosophie der Raum-Zeit-Lehre, in fact, the argument of the linguistic conventionality of the assumption regarding congruence is characterized by the following three fundamental aspects: (i) first of all, Reichenbach offers an analysis that aims at proving the absence of empirico-cognitive content (of a ‘direct’ type, as I will elaborate later) in the questions regarding the geometric description of physical space or, alternatively, of the relation of congruence; (ii) secondly, he states that these questions are devoid of any sense or meaning because they are devoid of any empirical-factual content; (iii) finally, he concludes that it is only by taking recourse to suitable conventions (the coordinative ones) that we can give them meaning. In other words, it is only by means of the implicit adoption of a verificational-reductionist theory of meaning that we can qualify as devoid of any meaning a statement such as the one concerning the self-congruence or rigidity during transportation of the differentially corrected rod. Consequently, we can consider as a stipulation concerning the fixation of meaning the convention asserting the rigidity of this rod in the course of its transportation (that is the assertion of the non-existence of universal deforming forces)15. To put it briefly, in order to justify the necessity of a convention concerning congruence and to assimilate it to a definitional or semantic-linguistic stipulation, Reichenbach first points out the lack of empirico-cognitive content of the assertion of congruence, then qualifies this assertion as devoid of meaning and, finally, states that we can talk about it in terms of truth or falsity only relative to a conventional assumption regarding linguistic rules. This argumentation seems to agree perfectly with a reductionist interpretation (which was establishing itself

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in those years) of the two most characteristic doctrines of Logical Empiricism: the verification principle and the linguistic theory of the a priori. Reichenbach is in line with a reductionist formulation of the verificational theory for two reasons. First of all, because – as was to become clear after Quine’s criticism of empiricism’s two dogmas – he implicitly takes as a unit of empirical meaning a single assertion, individually considered. In other words, Reichenbach states that the assertion of the rigidity of the differentially corrected solid rod statement is devoid of meaning on the basis of the fact that, if considered individually, it does not have any specifiable empirico-factual content. Secondly, because he implicitly considers the absence of direct empirico-factual content tantamount to the absence of any empirico-factual content. According to the linguistic theory of the a priori, all a priori assertions, beginning with the logico-mathemathical ones, have to be considered as analytical assertions, in other words as assertions whose truth value is based only on their logical structure and the meaning of the terms used. Analytical assertions, thus, are true in all conceivable circumstances and their truth is independent of the contingent facts of the world. This is why they tell us nothing about the world and have no factual content. In the neo-positivistic interpretation, therefore, there is a link between the analyticity of an assertion and the fact that it is devoid of empirico-factual content. It seems evident to me, though, that even admitting such a link, the step from the absence of empirico-factual content of the assertion of congruence, viewed by itself, to the assertion that the corresponding conventional assumption is of a semantic-linguistic sort – and so to the assertion of the analiticity or tautological nature of such an assertion once that the convention has been established – is possible only by implicitly taking for granted the non-validity of the thesis from which reductionism springs. In other words, in order to pass from one assertion to the other, we need to assume that an assertion devoid of direct empiricofactual content cannot even have an indirect content deriving from the network of relationships that connect it to the other assertions belonging to the theoretical system of which it is a part. As we know, the very recognition of this fact would lead Hempel and Quine, in the 1950s, to recover Duhem’s holism. They put aside any form of reductionism and defended the impossibility of formulating an empirical criterion of cognitive meaningfulness capable of making a clear distinction between a cognitively meaningful or meaningless discourse. The fact remains that, in 1928, Reichenbach discussed the problem of geometry using the verificational and reductionist terms typical of the classical neo-empiricist conception current during the active period of the Vienna and Berlin Circles. And these very terms allow him to justify the attribution to the coordination conventions of that linguistic-semantic value Schlick had defended since the early 1920s without having a fully developed philosophical justification of his position. Therefore, it is not surprising that at a certain point Reichenbach himself gave a classical formulation of neo-empiricist criticism of Kant’s theory of synthetic a priori judgements. During the first International Conference on

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Scientific Philosophy held in Paris in 1935, he presented a paper on the problem of the a priori in which we find again his criticism of Kant, but where there is no mention of the constitutive principles and all assertions are seen as either synthetic assertions deriving from experience or analytical assertions (“Tout ce que nous savons du monde est tiré de 1’expérience, et les transformations des données empiriques son purement tautologiques, analytiques” l6). 5. INTERPRETATIVE CONSEQUENCES

The path followed by Reichenbach between 1920 and 1928 (when certain ideas matured fully) and his change of perspective can help us – I think – to characterize the formation process of Logical Empiricism, its development and its crisis as a result of alternative theoretical perspectives. To illustrate this better, I will refer to Howard’s, Oberdan’s and Uebel’s interpretations mentioned at the beginning. Uebel seems to be perfectly right in saying that one of the essential characteristics of Schlick’s Allgemeine Erkenntnislehre was the anti-Kantian use of French Conventionalism, and that such a use was in line with the desiderata of the most representative exponents of the first Vienna Circle (Frank, Neurath and Hahn). Here, though, we need to be more specific about two points. First, when using the term “French Conventionalism”, we must refer mainly to Poincaré’s linguistic conventionalism. This regards both Schlick’s position and, partly, the more clear-cut direction that prevailed within the first Vienna Circle. In Allgemeine Erkenntnislehre Schlick does not mention the names of other important French epistemologists of the same period and, more particularly, he does not seem to know Duhem’s holistic conception. Frank, in his pages on the origins of Logical Empiricism and the first Vienna Circle, explicitly says that they looked at Poincaré’s conception in order to account for the subjective and abstract tracts of the scientific cognitive process in order to avoid both an old form of Kantism and a form of Machian sensism. It is certainly true that among the epistemologists mentioned there, Frank also included Duhem, but – with the exception of Neurath – Duhem, at least initially, does not seem have had as great an influence on the development of Logical Empiricism as Poincaré 17. Secondly, the ideas formulated by Schlick in the first edition (1918) of Allgemeine Erkenntnislehre, if considered separately, were not such that they excluded an interpretation of the philosophical meaning of the theory of relativity that did not ascribe to Kant any merits beyond the negation of a naively empiricistic or radically sensistic conception of knowledge. As I said before, Reichenbach’s position in Relativitätstheorie und Erkenntnis Apriori shows that Schlick’s conception of knowledge as coordination could be used to negate Kant’s theory of synthetic a priori judgements while still according a certain value to the idea of synthetic principles that, even though deprived of their apodeictic quality, still maintained a certain degree of constitutive value. If I inter-

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pret Philosophie der Raum-Zeit-Lehre correctly, then we have to say that, in order to abandon this idea completely, it was necessary to adopt a general philosophical conception centered around two doctrines typical of Logical Empiricism in its classic Vienna and Berlin version: the verification principle and the linguistic theory of the a priori. This interpretation allows us to consider as still valid the traditional view of Logical Empiricism that has always ascribed great degree of anticipation to the ideas developed by Schlick in the first edition of Allgemeine Erkenntnislehre, without forcing us to say, as Oberdan feared, that virtually all the essential conceptions of Vienna and Berlin Logical Empiricism were contained in that work. Actually, in order to arrive to these conceptions it was necessary to adopt the verification principle and the linguistic theory of logical truths neither of which had been clearly formulated in Allgemeine Erkenntnislehre. All this is confirmed by two letters written by Schlick in 1926 and 1927 when he was presenting the second edition of Allgemeine Erkenntnislehre. In the first one (7 March 1926) addressed to Rudolf Carnap, Schlick moves closer to the position that Carnap was elaborating and that was fully expressed in Der logische Aufbau der Welt. When communicating this evolution of his thought, he says that Carnap and himself agreed more than one might imagine on the basis of the revisions contained in the second edition (1925) of Allgemeine Erkenntnislehre: an adequate formulation of his new ideas – Schlick says – would have required him to revise his work much more exstensively. In fact, after the impact of Russell’s, Wittgenstein’s and Carnap’s ideas (Aufbau and Scheinprobleme), he changed his position and came to the conclusions expressed in the 1932 works “Positivismus und Realismus” and Form and Content. The second letter was addressed to Cassirer and was written one year later (30 March 1927) after the publication of “Erkenntnistheorie nebst den Grenzfragen der Logik und Denkpsychologie”, an essay where Cassirer also discusses the main theses of the Allgemeine Erkenntnislehre18. Schlick responds to some of the criticism put to him by Cassirer, who in a letter dated 4 March 1927 l9 had admitted he had overlooked the changes made in the second edition of Allgemeine Erkenntnislehre. In this sense, Schlick’s letter shows well the philosophical path that led him from the positions defended in that work to the ones formulated in the London lectures Form and Content (1932) where, following Russell and using the verification principle, he rejected as senseless the distinction between reality in itself and phenomenic appearence. So this letter shows very clearly the role played by Wittgenstein’s and Russell’s ideas on the development of Schlick’s thought towards the classic formulations of the Vienna Circle that he had anticipated in the essay-manifesto “Die Wende der Philosophie” (1930). When his ‘turn’ was complete, Schlick indicated as the starting points of his new philosophy the attention given to the problems of language, the argument regarding the tautological nature of logic and the linguistic foundation of the a priori, the representative conception of language and, finally, the verification principle which he described as “the fundamental principle of philosophizing” 20.

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It is only in light of the importance given to these ideas that we can understand the process that led to the most typical formulations of neo-empiricism. In Reichenbach’s 1928 work on the philosophy of space and time, these arguments are never mentioned explicitly nor do we find any mention of their connections with the problem of geometry. Even so, the argumentation in favour of the necessity of a coordinative assumption of congruence and its linguistic-semantic value seem to indicate clearly enough that it was only by means of an implicit reference to the verification principle and the tautological nature of the a priori that it was possible to abandon the idea of the constitutive a priori, as formulated in his 1920 work on the theory of relativity. Whether this was a theoretically valid move or not, whether this involved the emergence of a tension with Einstein’s perspective and, finally, whether this in some ways concealed a vision of the relationship between theory and experience less defensible than Cassirer’s, is a completely different story21.

NOTES 1.

2.

3.

4.

5. 6.

7.

D.Howard, “Einstein, Kant, and the Origins of Logical Empiricism” in: W.Salmon & G. Wolters (Eds.), Logic, Language and the Structure of Scientific Theories. Proceedings of the Carnap-Reichenbach Centennial, University of Konstanz, 21-24 May, 1991, Konstanz / Pittsburgh: University of Pittsburgh Press / Universitätsverlag, 1994, pp. 46-48; T. Oberdan, “Einstein’s Disenchantment”, in op. cit., pp. 107-108. T.Uebel, “On the ‘Austrian’ Roots of Logical Empiricism: The Case of the ‘First’ Vienna Circle”, a paper presented at the International Workshop “Analytical and Continental Aspects of Logical Empiricism: Historical and Contemporary Perspectives”, Florence, November 2-4, 1999, forthcoming in: P.Parrini, M.Salmon and W.Salmon (Eds.), Logical Empiricism. Historical and Contemporary Perspectives, Pittsburgh: University of Pittsburgh Press, pp. 1, 6 and 18 of the manuscript. M.Schlick, Allgemeine Erkenntnislehre (19181, 19252), English edition, General Theory of Knowledge, Translation by A.E. Blumberg, With an Introduction by A.E. Blumberg and H.Feigl, Wien & New York: Springer-Verlag, 1974, pp. 196-197. H.Reichenbach, Relativitätstheorie und Erkenntnis Apriori (1920), English translation with an Introduction by M. Reichenbach, The Theory of Relativity and A Priori Knowledge, Berkeley & Los Angeles: University of California Press, 1965, pp. 37-38 and 103-104 for the quotations; see also pp. 40, 42, 88. H.Reichenbach, Relativitätstheorie und Erkenntnis A priori, English edition cit., pp. 103-105. See M.Schlick, “Kritizistische oder empiristische Deutung der neuen Physik? ” (1921), English translation in M.Schlick, Philosophical Papers, vol. I (1909-1922), ed. by H.L.Mulder and B.F.B.Van De Velde-Schlick, Dordrecht: Reidel, 1979, pp. 323-324 and 333. If I understood correctly the answer Friedman gave me in Vienna during the conference, he did not seem to agree with my interpretation of Poincaré’s ideas. I am highly convinced, though, that the numerous passeges I quoted in the anthology Fisica e geometria dall’Ottocento a oggi, Torino: Loescher, 1979, III/7-9, clearly indicate that Poincaré gave a linguistic twist to his conventionalism. Please note that the passages quoted in section III/8 entitled “Il convenzionalismo di Poincaré e la critica di Duhem: convenzioni linguistiche e contenuto teorico”, testify to Duhem’s criticism of Poincaré’s argument according to which whatever a scientist creates in a scientific fact is the language used to express it. This aspect of the question has often been overlooked (see, for example, D. Gillies, Philosophy of Science in the Twentieth Century. Four Central Themes, Oxford: Blackwell, 1993, II/4-5); it is, on the contrary, a very important aspect of French epistemology between the late and early century.

20

8.

9.

10.

11. 12.

13. 14.

15. 16.

17. 18. 19.

20. 21.

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On this point see my paper “Reason and Perception. In Defence of a Non-linguistic Version of Empiricism”, in: P.Parrini, M.Salmon and W.Salmon (Eds.), Logical Empiricism. Historical and Contemporary Perspectives cit. See H. Reichenbach, “Der gegenwärtige Stand derRelativitätsdiskussion”(1922), English translation in Hans Reichenbach, Selected Writings: 1909-1953, Vol. II, ed. by M. Reichenbach and R.S.Cohen, Dordrecht: Reidel, 1978, pp. 38 and 44. For the letters, see P.Parrini “Origini e sviluppi dell’empirismo logico nei suoi rapporti con la ‘filosofia continentale’. Alcuni testi inediti”, Rivista di storia della filosofia, Vol. 48, 1993. See H. Reichenbach, Axiomatik der relativistischen Raum-Zeit-Lehre (1924), now in H. Reichenbach, Gesammelte Werke, ed. by A.Kamlah and M. Reichenbach, vol. 3: Die philosophische Bedeutung der Relativitätstheorie, Braunschweig/Wiesbaden: Friedr. Vieweg & Son, 1979, pp.1 (=13) and 5 (=17); English edition by M. Reichenbach with a foreword by W. Salmon, Axiomatization of the Theory of Relativity, Berkeley & Los Angeles: University of California Press, 1969, pp.3 and 8. H. Reichenbach, Axiomatik der relativistischen Raum-Zeit-Lehre cit., pp. 8-9 (=20-21); English edition Axiomatization ofthe Theory ofRelativity cit., pp. 11-12. H. Reichenbach, Philosophie der Raum-Zeit-Lehre (1928), English edition, The Philosophy of Space and Time, ed. by M. Reichenbach and J. Freund, with Introductory Remarks by Rudolf Carnap, New York: Dover, 1958, p. 37. For even clearer statements see also H. Reichenbach, “The Philosophical Significance of the Theory of Relativity” (in: P.A.Schilpp [Ed.], Albert Einstein: Philosopher-Scientist, Evanston, Ill.: The Library of Living Philosophers, 1949, Second edition, New York: Tudor, 1951, pp. 294-296) and The Rise of Scientific Philosophy ([1951], Berkeley & Los Angeles: University of California Press, 1966, pp. 135-137). Unfortunately the space at my disposal does not allow me to further elaborate on my archival work. See P. Parrini, Empirismo logico e convenzionalismo, Milano: Angeli, 1983, in particular Section 2.2. H. Reichenbach, Philosophie der Raum-Zeit-Lehre (1928), English edition, The Philosophy of Space and Time cit., Sections 3 and 4, in particular, from the final lines of Section 3, p.14, to p.16. H. Reichenbach, “L’empirisme logistique et la désagrégation de l’a priori”, in Actes du Congrès International de Philosophie Scientifique (Sorbonne, Paris 1935), Paris: Hermann, 1936, I: Philosophie scientifique et empirisme logique, p. 32. See P. Frank, Modern Science and Its Philosophy, Cambridge, Mass.: Harvard University Press, 19411, 1949 2. , pp.8-12 and 13-17. In Jahrbücher der Philosophie, Vol. 3, 1927, pp. 31 -92, see, in particular, Sec. 3, pp. 67-69. The numbers indicating the day and the month have probably been reversed. Regarding Schlick’s letter to Cassirer and the entire issue, see P. Parrini, “Origini e sviluppi dell’empirismo logico nei suoi rapporti con la ‘filosofia continentale’. Alcuni testi inediti” cit., in particular pp.391-392. M. Schlick, Form and Content. An Introduction to Philosophical Thinking, in M.Schlick, Philosophical Papers, Vol. II (1925-1936) cit., pp.286, 309; see also pp.361-362. I dealt with this theoretical question (discussed in the paper by Howard quoted above) in Knowledge and Reality. An Essay in Positive Philosophy, Dordrecht: Kluwer, 1998.

Department of Philosophy University of Florence I-50132 Florence, Via Bolognese 52 Italy [email protected]

ANITA VON DUHN

BOLZANO’S ACCOUNT OF JUSTIFICATION * Bolzano investigated the following problem. How can we determine whether or not a certain truth is basic without recourse to subjective criteria based on intuition or immediate perceptual knowledge? For him, the criterion of self-evidence is not a means for justifying propositions because it does not provide us with a scientific proof presenting the objective reasons for a proposition, reasons that hold independently of our knowledge.1 Bolzano intended to provide a workable alternative to the criterion of intuitive self-evidence, and claims that we have to search for proof even of self-evident propositions – at least until it becomes clear that and why no proof could be required.2 I reconstruct Bolzano’s account of justification, which is designed to replace the criterion of self-evidence and provide a scientific basis for the demonstrative sciences. I then argue that although Bolzano succeeded in devising a procedure for grounding truths, his theory fails on the account that it implicitly reintroduces an epistemological problem. 1. BOLZANO’S TWO RULES AND THE GROUND-CONSEQUENCE RELATION

Bolzano’s position on justification is close to the foundationalist view, according to which there are basic beliefs or, in his case, basic truths – which are justified without being based on other beliefs or truths – and upon which other beliefs or truths are based through valid inferences. His notion of justification has a dual purpose: it must show not only that there are basic truths, but also why they are basic. It serves as a criterion for establishing certain true propositions as axioms without resorting to intuition and, in addition, provides a means for discovering truths which are not accessible by means of insight.3 Hence Bolzano’s notion of justification has two aspects, an epistemological and a logical one. The epistemological aspect is that a justification is a mark which distinguishes knowledge – or true belief – from opinion and the logical aspect is that a justification is a strict derivative proof which excludes all relevant alternatives as well as alien intermediate concepts. The question is, did Bolzano succeed in combining these epistemological and logical aspects, and did he provide a foundation for the demonstrative sciences? The young Bolzano (1804) provides two rules for this purpose, both with regard to mathematics:4 21 F. Stadler (ed.), The Vienna Circle and Logical Empiricism: Re-evaluation and Future Perspectives, 21–33. © 2003 Kluwer Academic Publishers. Printed in the Netherlands.

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(1) We must search for proof even of self-evident truths, at least until it is clear that and why no further proofs could be required. (2) Even with a completely strict proof, we can allow ourselves to be satisfied if and only if it neither begs the question nor uses alien intermediate concepts or kind-crossing.

The first rule is designed to eliminate the criterion of intuitive self-evidence and to solve the epistemological problem of how basic truths can be known, if not through intuitive insight. Once we have clearly grasped the primary truths, we can extend a science by deriving further and new truths from the basic ones: by examining the reasons why a proposition we hold to be true is true, we not only increase our confidence in it, but by “drawing out the elements of an implicit deduction”, we “obtain the key to new truths which were not clear to common sense”.5 For example, the geometric proof of the truth that the angles at the base of an isosceles triangle are equal leads to the discovery of the truth that, in an equilateral triangle all angles are equal. The second rule warns against probationem per aliena et remota and kind-crossing, such as proving propositions about angles and relations between straight lines by referring to planes, or using the concept of movement to provide geometrical truths.6 Bolzano claims that a truth is justified or scientifically proved if and only if it is shown to be objectively dependent on other truths.7 That is to say, the relation between true propositions holds if and only if a primitive truth is the basis for a complex truth which follows from it as a consequence.8 He introduces an axiomatic order among truths: primitive truths or axioms are at the basis of more complex truths or theorems, and these two kinds are related by a dependence relation which Bolzano calls ground-consequence (Abfolge). If a truth p is based on another truth q, then p is a consequential truth. If we can prove that p is not based on q or a set of truths Q, then we can establish that p is a basic truth or axiom. Unlike the relation of derivability, which today is called logical consequence, Abfolge is a relation that holds only between true propositions which are compatible as ground and consequence.9 If p is based on a truth q (or a set of truths Q), p depends on q (or the set of truths Q), so p is true on the grounds of q (or Q).10 The ground-consequence relation is irreflexive11 because no truth can be based upon itself, and it is assymmetric12 because grounds are simpler than their consequences. Unlike the relation of derivability, ground-consequence is an intransitive13 relation with regard to the nearest grounds of a proposition. Bolzano claims that (i) if a proposition p is the nearest ground of a second proposition q, then q cannot be the nearest ground of p and (ii) if p is the nearest ground of q and q is the nearest ground of a third proposition r, then p is only a partial or auxiliary ground of r.14 In addition, Bolzano distinguishes between subjective and objective grounds and consequences as two kinds of implications: (1) confirmations or truths which, as premises, produce a cognition (Erkenntnis) or follow from a cognition

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as consequences, and (2) justifications where objective grounds and consequences hold among truths independently of our knowledge.15 In a confirmation (Gewissmachung), our aim is to obtain the certainty that a proposition is true and we obtain what he calls a ground of knowledge (Erkenntnisgrund). In a justification (Begründung), the truth of a proposition is derived from its objective base and we obtain an objective ground.16 We can confirm logical and mathematical truths by testing them empirically, or by repeatedly testing their derivation, but in a justification we can have no recourse to experience.17 In expounding upon the distinction between confirmation and justification, Bolzano follows his two rules for providing a sound basis for the demonstrative sciences; namely that we must search for proof even of self-evident truths, at least until it becomes clear that and why no further proofs could be required. This distinction is made explicit by inverting the order between the propositions which stand in a ground-consequence relation. In a justification, p is true on the grounds of q and q justifies p. In a confirmation, I know that q is true on the grounds of p and p confirms q.18 I know that q is true on the grounds of p because p explains why q is the case, whereas in a justification, p is true on the grounds of q and q justifies p, because it explains why p is the case. With regard to the first rule and his distinction between confirmation and justification, Bolzano takes up the Aristotelian distinction between and and criticizes the latter for distinguishing between two kinds of knowing or understanding rather than between an objective justification and a subjective confirmation.19 Aristotle distinguishes between (1) knowing that p on the grounds of q where q explains why p is the case and (2) knowing that p on the grounds of q where q does not explain why p is the case.

In the first case we understand a fact through its explanation, and in the second case we become acquainted with a fact without any scientific demonstration.20 Bolzano, however, distinguishes between objective or logical grounding of truths and their subjective or epistemological grounding:21 (1) p is true on the grounds of q and q explains why p is the case, so q justifies p and (2) I know that q is true on the grounds of p because p explains why q is the case, so p confirms q.

He rejects the Aristotelian view which bases the distinction between Erkenntnisse or true judgments and Wissen or scientific knowledge on whether we are acquainted with their objective grounds. But this criterion for knowing something is itself a cognitive or subjective one: the distinction is not simply between unjustified and justified knowledge, but between true judgments or cognitions which we know to be justified and true judgments which we know to be not

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justified.22 This raises another epistemological problem, as Bolzano recognized: how do we become acquainted with the grounds of a cognition other than through intuition or insight? How do we know whether a true judgment is justified or not? Bolzano remarks that if our distinction is between two kinds of cognitions, the words “grasping (Begreifen)” or “insight (Einsehen)” would be more appropriate than knowing (Wissen), in order to qualify such Erkenntnisse as clear insights.23 However, his own distinction is problematic as well, at least with regard to the justification of basic truths, where the epistemological question remains. I discuss this point below in section 3. A confusion between a confirmation and a justification violates the second rule that our proofs may neither beg the question nor use alien intermediate concepts or kind-crossing: If a subjective confirmation is mistaken for an objective justification due to a failure to note the reverse order of the propositions, what results is not a grounding proof. Bolzano explains that geometers did not state the correct ground of the truth to be demonstrated because they inverted the order between the propositions in the proof of the first theorem in Euclid’s Elements. Consequently, some scientific proofs are not grounded proofs (justifications), but only confirmations. For example, the truth that an equilateral triangle is possible contains the objective ground of – or justifies – the truth that two circles intersect, “but if one only pays attention to the mere knowing, then the converse relation might quite easily occur”.24 Two circles intersect or have a point in common, because for every two points a and b there must be a third, c, which has the same distance ab from both a and b, so that ca = cb = ab. We can easily mistake a confirmation for a justification, however, by inverting the order of the propositions in the demonstration. We know that an equilateral triangle is possible by confirming this on grounds of the truth that two circles intersect. 2. BOLZANO’S JUSTIFICATION OF AXIOMS

Bolzano examines the requirements for an axiomatic method (1804) and claims that (1) more general and simpler truths are the ground of the more particular and more complex ones and that (2) it is not enough for an axiom to be certain or self-evident. In addition, we must follow the first rule and search for a proof of it, at least until we become clearly aware of the reasons why no proof could ever be required.25 Axioms are unprovable propositions composed of simple concepts,26 but it does not follow from their unprovability that they are self-evident. He wants to establish axioms on logical grounds and therefore rejects the psychological criterion of self-evidence by claiming that we cannot justify the truth of a conceptual proposition by assuming that it is intuitively self-evident. For this reason, he introduces a distinction between the objective justification (Begründung) of basic conceptual truths and their subjective ascertainment (Gewissmachung), which he opposes to the traditional view that basic conceptual truths

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are immediately obvious or intuitively self-evident.27 We can reconstruct his claim as follows: (1) Conceptual truths, unlike perceptual truths, cannot be known (wissen) immediately or be self-evident,28 although we can come to know them (erkennen) without inferring them from other truths – but in this case we do not have a clear Erkenntnis. We come to know a truth clearly (deutlich) if and only if we are aware of its ground.29 (2) Conceptual truths may be subjectively plausible (einleuchtend) and even certain, but we need to prove their objective grounds.30 We can be immediately aware of conceptual truths, but we are not immediately aware of their objective grounds.31 This notion of justifying or grounding axioms seems to originate with Leibniz, but Bolzano does not mention this. Leibniz uses his principle of sufficient reason as a call to ground axioms.32 Even though Leibniz explicitly states the need for a grounding of Euclidean axioms, he does not elaborate a deduction as Bolzano does. For both Leibniz and Bolzano, we have immediate knowledge of the primary truths of reason, or conceptual truths, but whereas Leibniz explicitly states that such knowledge is intuitive,33 Bolzano does not specify the nature of this knowledge, except for saying that the principle of sufficient reason is the first expression of our awakening reason (Vernunft), to always inquire about the ground.34 Rather, he assumes that there must be primary propositions, whose truth we recognize “from them themselves” 35, or by understanding the meaning of their components, for otherwise we could neither make any grounded inferences, nor show (erweisen) that some statements cannot be grounded.36 For Bolzano, a proposition cannot be both an axiom and a theorem, since axioms are not arbitrary propositions, but basic truths from which the other propositions in a theorem are derived.37 Moreover, inverting the order of ground and consequence in a proof violates the second rule: Bolzano points out that the Euclidean proposition “a straight line is the shortest distance between two points” cannot be inferred from propositions referring to triangles or planes, since these latter are either proofs per aliena et remota, because they use concepts not contained in the axiom, or they are begging the question because they presuppose the basic truth rather than containing it as a component and thus inverting the order of ground and consequence.38 This claim, and the intransitivity of the ground-consequence relation with regard to nearest grounds, commits him to saying that theorems cannot be undecidable. If a proposition p is the nearest ground of a proposition q and q is the nearest ground of a proposition r, then q cannot be the nearest ground of p, nor can p be the nearest ground of r. Since the ground-consequence relation is intransitive with regard to nearest grounds, axioms cannot be both grounds and consequences. This is problematic from a modern point of view, since some theorems are undecidable. If we admit that axioms have an arbitrary nature, rather than claiming that they are basic propositions underwriting other propositions, then any indemonstrable proposition in a theorem can function as an axiom

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– but Bolzano would reject this idea. Bolzano did, however, take some steps towards modern mathematical logic by re-defining axioms as non-intuitive propositions and by determining them through an implicit definition, through their relationships to other propositions: axioms are true propositions which are not consequences of other propositions. The problem, from a modern point of view, is that he attempts to define the nature of these propositions by defining them as basic conceptual truths, albeit on the criteria of independence and consistency.39 How does Bolzano determine which propositions are axioms or primitive truths and which propositions are theorems or consequences? And how does he justify axioms? He determines the nature of axioms to be unprovable by showing that they are primary truths which cannot be derived from any other propositions as consequences. p is a basic truth if and only if p is composed of simple concepts, which are indefinable, and if there is no truth q or set of truths M,N,O, upon which p is based. One such basic truth is the axiom “There is something”.40 Another is the principle of sufficient reason. He uses a regressive proof or backward demonstration from consequences to ground which he calls a deduction or derivation (Herleitung).41 This is an exact derivation which eliminates redundant premises or redundant components of premises, and in which grounds must be simpler than their consequences. A proposition p is justified as an axiom if and only if we can show that for a given proposition “A is B”, there are no two propositions of the form “A is X” and X is B” from which “A is B” could be inferred.42 In other words, in order to justify a proposition as an axiom, we must rule out all relevant alternatives.

2.1 Bolzano’s claim that the self-evidence of basic truths is not immediately obvious (einleuchtend) but must be established Bolzano’s justification of axioms has a further purpose, which is to refute the claim that basic conceptual truths are intuitively self-evident and need no further justification. In 1837, he objects to the thesis held by older logicians who, instead of giving a proof for basic truths, merely state that there is a truth “die für sich selbst einleuchtet” .43 Such intuitive self-evidence of a proposition is no proof of its truth. In Religionswissenschaft (1834), he says that it is easy to convince someone of the truth that it is colder in winter than in summer, merely by referring to “ das bloße Gefühl” . Likewise, he adds, it is easy to convince anyone, even the most stupid person, of the truth that a straight line is the shortest distance between two points, merely by asking him to span a thread between two points and to let him notice that, as he stretches the thread, the distance between the two points becomes shorter as the thread takes the position of a straight line. But is this how we make him understand the reason (Grund) why the straight line is the shortest? 44 Surely not, for all we have done is to confirm the axiom

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without providing a justification. Similarly, the drawing of a triangle confirms that the sum of 3 angles is equal to 180°, but it does not prove the theorem. In 1810, he objects to the claim that the characteristic of an axiom lies in its intuitive nature (Anschaulichkeit). This property, he says, “is hardly suitable to provide a firm basis for the classification of all truths into two classes, that is, into axioms and theorems”. He gives three reasons for the unsuitability of intuitiveness. First, this property allows for differences in degree, so we will not be able to determine precisely what degree would be sufficient for an axiom. Second, the intuitive nature depends on fortuitous circumstances, such as our education or experience, which brings us to recognize it more frequently or less. Third, the degree of intuitiveness differs from one person to another and what is obvious for one may appear obscure to another.45 Further on, he gives a fourth reason, which he also mentions in 1837.46 Clear propositions, if they are conceptual, are not necessarily intuitively self-evident, but rather, they are clear to us because they are inferred from other, more basic truths. I think that what he objects to is an inherent confusion in the word “ Evidenz” , which may be due to the fact that it means both visibility and clarity or transparency. Bolzano distinguishes between visibility or intuitive selfevidence and the clarity or transparency of a proposition, as it becomes obvious to us. Perceptual truths can be intuitively self-evident, though even in their case Bolzano restricts the self-evidence to immediate judgments, where something is predicated on the first-person subject.47 Conceptual truths, however, appear clear to us only because they are inferences. For this reason, he says, the proposition “you should not lie” may appear much clearer to us than its objective ground, the axiom “you should promote general well-being”, because it presupposes the latter.48 So inferred propositions often have a higher degree of intuitiveness than axioms, which is why we are bound to confuse the order of ground and consequence in a proof.49 For although we can be immediately aware of conceptual truths, we are not immediately aware of their grounds. In addition, he claims in the Anti-Euclid50 that in a scientific presentation, the insight (Einleuchten) of a true proposition is not immediate, but must be established by means of derivations from simpler truths. We must be able to perceive the correctness of such an inference without seeing the figure to which it refers. In the Wissenschaftslehre51 he states explicitly that conceptual truths are not immediately self-evident or obvious, but are testable (prüfen) either through experience or repeated derivation. A proposition is more likely to be obvious if it is inferred from others, or tested empirically. This claim, however, leads to another problem, which I will now examine, in section 3. For testing is confirming, but not justifying. It seems that Bolzano’s claim that the self-evidence of basic truths is not immediately obvious but must be established, takes him back to the problem of confirming truths and results in an epistemological problem in his theory: we can logically justify truths, but we may need non-logical knowledge for having access to them.

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3. BOLZANO’S VIEW ON CONFIRMING OR TESTING TRUTHS AND AN EPISTEMOLOGICAL PROBLEM IN HIS THEORY

How do we learn or come to know that a proposition is true or that a logical relation, such as that of ground and consequence, holds between true propositions? Bolzano claims that ultimately all subjective grounds of knowledge have an objective base,52 but how do we come to know that base? The obvious answer is, through logical knowledge or knowledge by means of concepts, by understanding the components of the conceptual propositions. He establishes axioms as conceptual truths which are unprovable but not intuitively obvious and claims that “the domain of axioms stretches as far as that of pure simple concepts” which are indefinable.53 Axioms implicitly define the items referred to by concepts such as [point] or [line] and we must have an understanding of what these items are, in order to prove a geometrical theorem. Here we are faced with a dilemma: either we say that we cannot know what [point] or [line] are without knowing a geometrical theory, or we accept that we have a naïve understanding of these concepts which we then clarify by means of a geometrical theory. So even though we may assume that we come to know axioms because we have already understood their components, a problem remains, concerning the nature of this understanding. Even if we appeal to conceptual understanding, or to conventions, how do we explain our grasping the meaning of these components without an ultimate recourse to insight or intuition? Here is a possible Bolzanian reply: Bolzano says that there is “a peculiar connection” between the components of a subjective proposition or judgment, which must be “combined with one another in a certain quite distinctive way.” He is not very clear about the nature of this connection; all he says is that “it must be a sort of mutual influence these ideas have upon each other.” 54 Further on he explains that a judgment is not merely a sum of ideas, but a “certain efficacious combination (wirksame Verbindung) of ideas”.55 Bolzano calls the degree of this efficacy the degree of confidence (Zuversicht) with which we make a judgment or the degree of certainty with which we hold something to be true. Perhaps he means that we understand a statement when we grasp its components with a sufficiently strong degree of confidence, that is, our conviction is the glue that holds the components of a judgment in a certain order: when we hold a statement to be true, we provide an efficacious combination of its components. So we understand the components of a basic truth by holding their order to be true. If the components of a proposition are determined by their order, which Bolzano holds,56 then their meaning is determined by this order, and we understand their meaning by understanding their order and holding it to be true. It follows that for Bolzano a statement implicitly defines its components, these latter being related in a certain order, which we hold to be true. So our understanding has a rather pragmatic, if not to say dogmatic, character.

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But this still leaves us with the problem of how we get to the primitives: Bolzano’s Herleitung of axioms is a deductive procedure, whereas his regressive proof for getting to the primitives would seem to require an inductive procedure. Let us take Bolzano’s above-mentioned example of a basic truth “there is something”: in order to establish this statement as a basic truth we must understand what “there is” and what “something” is. How can we come to know this by means of a deductive procedure? The statement is uninformative, so we cannot “unpack” its semantic content and lack criteria for proving that it cannot be derived from any other propositions as a consequence. The regressive procedure from consequence to ground calls for an inductive procedure which enables us to discover – and thus understand – the statement. Once we have discovered several truths in this way, we can then derive other statements from them as consequences. Bolzano’s deductive method for justifying axioms does not provide us with criteria for determining which truths are primitive because it does not contain an explanation of how we are supposed to understand primitive truths and the meaning of their components.57 Unfortunately there is a further problem within his own theory. Bolzano seems to say that a priori or conceptual truths cannot be justified through experience and that the objective ground of conceptual truths cannot lie in observational propositions. He also points out that a justification is possible above all in conceptual sciences, but more rarely in empirical sciences, because very often the objective reason is completely or partly unknown to us. Hence we cannot provide a justification by deriving them from their objective reasons, and in our attempts to support their proof we only increase their degree of probability.58 Bolzano’s claim that conceptual truths can be tested either through experience or by repeatedly testing their derivation59 has provoked Husserl’s and Stove’s accusation that he is an empiricist who holds that we believe logical generalizations because they are true observation-statements.60 I think, however, that their accusation is partly unjustified, for Bolzano argues, on the contrary, that we cannot generalize from observation or empirical intuition: we can come to know, by observation, that a single line can be extended, but we cannot infer from this the general truth that all straight lines can be extended. For this generalization we need to appeal to the principle of similarity. So we do not learn general truths through intuition, but through conceptual principles.61 Bolzano’s claim about our empirical knowledge of logical and mathematical truths is much weaker: he claims that we can learn or become acquainted with logical truths by experience and we can confirm such truths by testing them empirically. For example, we can learn the syllogistic form of barbara, that “x is F and all F are G” implies “x is G”, for all x and all F and all G, by testing it against experience. We discover that in all observed instances, if both the premisses of the barbara form are true, then the conclusion is true and that there are no instances of barbara where the premisses are true and the conclusion is false. This implies that our verification not only grounds our confidence in logical rules and mathematical propositions, but also the justification for the applicabil-

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ity of these rules. And here the accusation has a point, for Bolzano’s attempt to combine epistemological and logical aspects leads to an inconsistency in his account of justification.62 However, the point here is not so much that Bolzano is an empiricist, but rather that such a combination inevitably results in problems, at least as long as it includes formal logic. To answer the question put at the beginning of this paper, I think that Bolzano’s notion of justification is probably as adequate a foundation for the demonstrative sciences as you could get in the century, and its shortcomings may be due to the problem of justification itself, rather than to Bolzano’s account.

NOTES

*

1.

This text is a revised version of a paper presented at the symposium “ Vienna Circle/Logical Empiricism”, July 2001 and is closely related to a larger project I am presently working on, concerning Bolzano’s epistemology. I would like to thank Michael Beaney and Ivan Kasabov for their critical comments. References to Bolzano, unless otherwise indicated, refer to the Bernard Bolzano Gesamtausgabe, ed. E. Winter, J.Berg, F.Kambartel, J.Louzil, B.van Rootselaar; Stuttgart Bad-Cannstatt, F. Frommann-Holzboog Verlag, 1969-(BBGA).

1804, § 3 (Betrachtungen über einige Gegenstände der Elementargeometrie (1804) in Bolzano ’s early mathematical works, Czechoslovak Studies in the History of Science, Prague, 1981. partial English translation by S. Russ in W.Ewald, From Kant to Hilbert, vol. 1, OUP, 1996); Beyträge II (1810), §§2, 11, 12, 21 (Beyträge zu einer begründeteren Darstellung der Mathematik (1810) in Bolzano’s early mathematical works, op.cit. (Beyträge). English translation by S. Russ in W.Ewald, op.cit.); 1817 (Purely analytic proof ...), § 1; English translation by S.Russ in W.Ewald, op.cit; WLIV, §525; (Wissenschaftslehre (1837), 4 vols, Aalen, Scientia Verlag, 1981 (WL)) and the Anti-Euklid, a manuscript in Bolzano’s Nachlass edited by Karel Vecerka, Sbornik, Prague, 1967, pp. 204-215, who dates the text around 1840. Jan Sebestik, however, situates the text closer to 1816. 2. 1804, §3. 3. Cf. WLIV, §401, §525. Cf. on this Ali Behboud (2000), Bolzanos Beiträge zur Mathematik und ihrer Philosophie, ch, 1, Bern Studies in the History and Philosophy of Science, Bern. 4. “Erstlich stellte ich mir die Regel auf, dass ich mich durch keine Evidenz eines Satzes von der Verbindlichkeit los zähle, noch einen Beweis für denselben aufzusuchen – so lange, bis ich deutlich einsähe, dass und warum sich durchaus kein Beweis fernerhin fordern lasse. [...] so muss man das Bestreben alle Wahrheiten der Mathematik bis auf ihre letzten Gründe zu entwickeln, und dadurch allen Begriffen dieser Wissenschaft die möglichste Deutlichkeit, Berichtigung und Ordnung zu verschaffen, [...]. 1804, Preface, pp.6-7. Cf. also 1810, II, §2, 1817, § 1 ; Anti-Euklid, p. 208. 5. 1804, Preface, p. 8; 1810; Beyträge II, § 2; WLIV, §401. 6. Cf. 1804, Preface, pp. 8-9. 7. Beyträge II, (1810), § 12. cf. also 1817, § 1 where he says that scientific proofs should be justifications and introduces the distinction between Grundwahrheiten and Folgewahrheiten. 8. WLII, § 221. note. 9. “ein sehr merkwürdiges Verhältnis, vermöge dessen sich einige derselben zu andern als Gründe zu ihren Folgen verhalten.” WLII, § 162; §221.note: “der Begriff einer solchen Anordnung unter den Wahrheiten, vermöge deren sich aus der geringsten Anzahl einfacher Vordersätze die möglich grösste Anzahl der übrigen Wahrheiten als blosser Schlusssätze ableiten lasse”. 10. Cf. WLII, §198. 11. WLII, §204.

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12. 13. 14. 15. 16. 17.

18. 19. 20.

21.

22. 23. 24.

25. 26. 27.

28. 29. 30. 31. 32.

33. 34.

35. 36.

31

Cf. WLII, §209. Cf. WLII, §213. Cf. WLII, §213, note. WLII, §198. ML, § 13 (Von der mathematischen Lehrart (1833-1841) in BBGA, II, A, vol.7, Grössenlehre. (ML)); WLII, §162. The distinction between confirming and justifying is not the same in the formal and the natural sciences, because in the latter, it is a causal relation which must be justified. In the natural sciences, both confirmation and justification are related to experience, but although a justification may involve an observational element, it must have a non-empirical base. In the formal sciences, only the confirmation may occur through experience. Cf. WLIV, §525; ML §13. Cf. WLII, § 198, cf. also ML, § 14, WLIV, §525. Aristotle, Posterior Analytics, A13, 78a-b, trsl. Jonathan Barnes (1975), Clarendon, Oxford. Cf. Barnes’ commentary, p. 155. In addition, Bolzano mentions Leibniz’s “liaison de vérités” as a predecessor of his own notion of connection between truths as ground and consequence. There is a clear parallel between the two authors, since both Leibniz and Bolzano distinguish this logical relation from the epistemological connection betweeen truths as cognitions. Cf. WLII, § 198, note. As Bolzano points out: “the Greeks required that we only say of something that we know it, if we have come to know it from its ground.” Cf. WLIII, § 316.4 & note. 1. WLIII, §316.4. Cf. WLIV, §525; Anti-Euklid, pp.210-211. Bolzano explains that geometers did not state the correct ground of the truth to be proved because they inverted the order between the propositions in the proof of the first theorem in Euclid’s Elements. Therefore some scientific proofs are not grounded proofs (justifications), but confirmations. Cf. on this Paolo Mancosu (1999), “Bolzano and Cournot on mathematical explanation” in Revue d’histoire des sciences, vol. 523/4, pp. 436-43 7. Cf. 1804, preface, op.cit. note 4. Beyträge,II, §19. Cf. Beyträge, appendix on the Kantian construction of concepts through intuitions (Anhang über die kantische Lehre über die Construction der Begriffe durch Anschauungen (1810) (appendix to Beyträge), in Bolzano’s early mathematical works, op.cit. English translation by S.Russ in W.Ewald, From Kant to Hilbert, op.cit.; WLIII, §305.5; §314.3. Bolzano’s attack is directed in particular against the Kantian view that mathematical concepts are constructed through intuitions and that axioms are indemonstrable because they are intuitively self-evident. Cf. KrV, A732/B760. Cf. WLIII, §300.13. Cf. WLIII, §§300.9, 316.3. Cf. WLIII, §§ 305, 314; Anti-Euclid, pp. 208-209. Frege has a similar claim in Logic in Mathematics, (1914), The Frege Reader (1997), Michael Beaney ed., p. 310. Cf. WLIII, §§313, 315.6, 316.note 1. Cf. G.W.Leibniz, Die philosophischen Schriften, vol.4, 2. Abtheilung, Berlin 1880, p. 232. Cf. on this J. Mittelstrass (1969) “Die Begründung des principium rationis sufficientis” , in Studia Leibnitiana, Supplementa, vol.3, pp. 136-148. For instance, when referring to definitions, Leibniz asserts that they include intuitive knowledge because they include a primary truth of reason. New Essays on the Human Understanding (1765), trsl. P. Remnant & J. Bennett, CUP, Cambridge, 1981. bk. IV, ch. ii, p. 367. Cf. WLIII, §311.2. Bolzano qualifies our capacity to come to know a truth or make a true judgment as a “feeling for truth” (WLIII, §316.3, 316.note 1) through which we can come to know a truth without coming to know its ground. Cf. on this Anita Konzelmann (2001), “Intuismus oder Empirismus? David Stoves Bolzano-Kritik ” forthcoming. Fortunately – for otherwise his critical view of self-evidence would collapse – Bolzano does not say that this is how we come to know primary truths. Rather, this feeling for truth applies to grounded truths, cf. WLIII, § 316.3. Beyträge, II, § 19; WLIII, §300.9. Cf. WLIII, §§300.9, 316.note 1.

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ANITA VON DUHN

37. Cf. Beyträge (1810), §13. 38. 1804, § 10, Anti-Euclid, pp. 210, ff. 39. An axiom is independent if and only if it cannot be derived from the remaining ones and it is consistent if and only if no contradiction can be derived from it. 40. WLII, §214. 41. Cf. 1810, Beyträge, II, §21. 42. “Behaupten wir also, a) dass ein Satz eine Grundwahrheit sey: so müssen wir (...) darthun, dass (...) keine einzelne, auch kein Inbegriff mehrer Wahrheiten angeblich sey, aus denen er sich wie eine Folge aus ihrem Grunde ableiten lässt.” (WLIV, §577). “Dieses wird in den meisten Fällen eine eigene Betrachtung erfordern, die ich zum Unterschiede von einem eigentlichen Beweise (oder einer Demonstration) mit dem bestimmten Rahmen einer Herleitung (oder Deduktion) belege. Grundsätze werden also zwar nicht bewiesen, wohl aber deduciret, und diese Deductionen sind ein wesentlicher Bestandtheil des wissenschaftlichen Vortrages, indem man ohne sie niemals gewiss seyn könnte, ob jene Sätze, deren man sich als Grundsätze bedienet, dieses auch wirklich sind.” (Beyträge II, §21, my italics). 43. WLII, §214.note. 44. RWI, §3. Lehrbuch der Religionswissenschaft, 3 Teile, Sulzbach, 1834, BBGA, I, vols.6-8. 45. 46. 47. 48. 49. 50. 51.

52. 53.

54. 55. 56.

57.

58.

59.

(RW) 1810 (Beyträge II, §10). Cf. WLIII, §§300, ff. Cf.WLIII, §300.12. 1810 (Beyträge II, § 21; Appendix, § 10). Cf. Appendix, 1810, §10. Cf. Anti-Euclid, p. 209. WLIII, §315.14; cf. also Appendix 1810, § 10, where he claims that one can very easily test the results of mathematics by intuition and experience and that the axiom of the straight line being the shortest between two points is proved by everyone by innumerable experiments long before they can prove it by deductions. He adds that the well-known obviousness of mathematics gradually disappears where experience is lacking. Cf. WLII, §221.note; ML § 13;WL§198. Beyträge II, §22. “Wenn nämlich alle mathematischen Begriffe erklärbare Begriffe wären, so könnte es auch keine Grundsätze in den mathematischen Disziplinen geben. Da es aber einfache Begriffe gibt; (...) so muss man (...) auch wirkliche Grundsätze in [der Mathematik] anerkennen”. WLIII, §291. WLIII, §293. Bolzano claims that the components of a proposition are related in a certain order: a subject A has a certain attribute b. The canonical form of propositions is “ A has b” . Cf. WLII, §§ 126, 127. Perhaps the problem lies in the fact that he himself does not seem very clear about precisely which propositions are the basic axioms on which the demonstrative sciences are based for (to my knowledge), he makes no explicit statement to that effect. He only assumes that there must be more than one basic truth. WLII, §215, §221.3. WLIV, §525. Bolzano’s view implies that non-logical knowledge is necessary for coming to know the logical grounds of a proposition, at least in empirical sciences, because we cannot justify empirical laws without observational knowledge. Bolzano could object that for a justification in the natural sciences, my observation statements must be related by a conceptual relation of ground and consequence. Physical truths are truths of reason which, for their derivation, require the clear presentation of a purely conceptual truth, even if they also require a perceptual premiss. Cf. WLIII, § 311.2. But when we confront Newton’s law that there is a force of attraction between any two particles in the universe with observation statements, we also give valid reasons for it and, in so doing, we justify it without having to recur to the logical relation between propositions. “If we have not tested the truth of a proposition either by experiment, or by repeated checking of its derivation, we do not give it unqualified assent (...). Does not experience teach us that we make mistakes in mathematical judgments, and that we make these mistakes more easily the more we trust what that philosophy calls by the high-sounding name of pure intuition? (...) The

BOLZANO’S ACCOUNT OF JUSTIFICATION

33

only reason why we are so certain that the rules barbara, celarent, etc. are valid is because they have been confirmed in thousands of arguments in which we have applied them.” (WLIII, §315.4, my italics). 60. “[Bolzano] would have firmly rejected the idea of a pure logic in my sense – and, even more, in the sense of a pure logic “to be clarified” epistemologically. (...) No one has taken notice of the fact that Bolzano’s epistemology rests upon the foundation of an extreme empiricism. (...) there is here no difference between Bolzano and his contemporary, John Stuart Mill.” Husserl (1913) Introduction to the Logical Investigations, Martinus Nijhoff, The Hague, 1975, p.48. David Stove (1986) The rationality of induction, part 2, Clarendon, Oxford, pp. 160-162. 61. Cf. ML, § 14. 62. Cf. on this Mark Textor (2001), “ Logically analytic propositions a posteriori?” , in History of Philosophy Quarterly 18, 1, who argues that non-logical knowledge is necessary for determining the truth or falsity of logically analytic demonstratives. This fallacy in Bolzano’s theory pervades even his logic. He claims that logical relations hold between true propositions independently of our knowledge. But in some cases we can only come to know that a relation of derivability holds between truths if we have non-logical knowledge. Cf. WLII, § 197.3, § 155.

Institute for Literature Bulgarian Academy of Sciences Blvd. Shipchenski prohod, No. 52, block 17 1113 Sofia Bulgaria [email protected]

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DAVID JALAL HYDER

KANTIAN METAPHYSICS AND HERTZIAN MECHANICS *

l. INTRODUCTION

People interested in the history of the philosophy of science generally know about Heinrich Hertz, the discoverer of electric waves, and the author of a work (the posthumous Principles of Mechanics) whose picture-theoretical account of science was adopted or criticised by Mach, Boltzmann, Wittgenstein, Hilbert and many others. Despite the Principles’ great influence, there is no consensus on what exactly Hertz was up to when he wrote that peculiar book. How did Hertz understand its significance? As a work in theoretical physics? As a philosophical treatise? If both, what is the connection between these two components? In this paper I shall argue that Hertz’s Principles of Mechanics is an instance of what Kant called for in the introduction to his Metaphysical Foundations of Natural Science, and claimed to deliver in the book itself, namely a “metaphysics of corporeal nature.” A metaphysics of corporeal nature is an a priori construction of the concept of matter. Such a construction lays the groundwork for the unified system of science by rigorously relating metaphysical principles to the intuitions of space and time. When I say that Hertz’s book is an instance of this species, I do not mean to suggest merely that one can think of it that way, for I believe that there is evidence to suggest that Hertz thought of it that way too. Some of that evidence has become available to us recently in an edition of a series of lectures which Hertz delivered at the university of Kiel in 1884, immediately before he began the series of experiments which led to his landmark works on electromagnetism. The title of the manuscript of these lectures, which appears to have been intended for publication as a book, is Über die Konstitution der Materie.1 Most of the philosophical ideas one associates with Hertz – his “picture-theory”, his scepticism regarding action at a distance – are articulated here, and we find the same mix of scientific realism and neo-Kantian idealism that makes Hertz so interesting a figure for philosophers. Hertz had been reading Kant’s Metaphysical Foundations in the previous semester, and his lectures are directly concerned with the proper way of framing the concept of matter. This is in part what he takes the “science of the constitution of matter” alluded to in the title of the manuscript to be: a specification of the concept of matter which will prepare it for drawing up the pictures which scientific cognition requires to go about its work. Although it would be mislead35 F. Stadler (ed.), The Vienna Circle and Logical Empiricism: Re-evaluation and Future Perspectives, 35–46. © 2003 Kluwer Academic Publishers. Printed in the Netherlands.

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ing to claim that Hertz’s early lectures are a simple extension of Kant’s project, they still clarify the extent to which Hertz used Kant’s philosophy to guide his philosophical thinking. Unlike many of his contemporaries, unlike even his teacher, Helmholtz, Hertz’s debt to Kant does not stop at theses concerning the unknowability of things in themselves, or the aprioricity of time and space, but extends to his ruminations on the concept of matter and on the notion of an a priori construction of the latter. And although Hertz, even at this early stage, was inclined to reject the Kantian claim that force was essential to matter, he went about rejecting that claim, in his posthumous work, by trying to show that an a priori construction of matter could be achieved without recourse to that notion, that a complete mechanics did not require force of matter. Even where Hertz argues against Kant, he uses Kantian methods to do so. Hertz’s understanding of the term matter in these lectures is not quite what one might expect. He explains what he means with a long analogy between matter and paper money, calling matter a currency issued by our understanding in order to settle its relations with things. Paper money, Hertz explains, is a sign for something else, and this alone constitutes its meaning and its value, in that it does not matter to this end how it is physically made. Hertz uses this somewhat Helmholtzian analogy to distinguish between three kinds of sciences concerned with this intellectual currency. The first of these disregards the semiotic character of matter, and considers it as a thing in itself. Such are the sciences of physics and chemistry in their everyday applications. The second kind of science is more directly concerned with the essence of matter, much like a science concerning the laws of circulation of paper money. This science, although it is conscious of the sign-character of the concept it analyses, does not need to consider specific details of the fabrication of these signs. It comprises the theoretical parts of physics and chemistry, as well as the science which Hertz is trying to situate, namely, that of the constitution of matter. The last kind of science is one concerned with the concept in itself, and is like a science which studies the fabrication of money – the kinds of paper to use, the engraving techniques and the inks. This is the domain of philosophy, “whose responsibility it is to descend into the workroom of our understanding, and to determine how it comes to make such concepts.” 2 In his ensuing discussion, Hertz goes on to present the state of contemporary atomic, electromagnetic and ether theories, as well as attacking the concept of force and considering the claim to metaphysical priority of a number of material concepts. It is here that the picture-theory makes its first appearance in Hertz’s works. I believe that these early discussions represent a thoughtful reaction to Kant, and that much of Hertz’s later work is best understood from that point of view. Above all, many particularities of the structure and argument of the Principles of Mechanics are easier to understand if one approaches the work from this angle. My approach in the following is loosely chronological, for I want to argue for a continuity in Hertz’s thought which has been overlooked, largely because the early work I will be discussing has been unavailable. I begin with a brief review

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of Kant’s notion of a metaphysics of corporeal nature, turning from that to a treatment of the picture-theory of scientific cognition as it appears in Hertz’s Constitution of Matter and his Electric Waves. I conclude with a section on the Principles of Mechanics, where I claim that the Principles should be read as providing a science of the constitution of matter in the sense already envisaged in the Constitution of Matter, and that this is reflected in formal analogies between the Principles and Kant’s system.

2.

KANT’S METAPHYSICAL FOUNDATIONS

These connections are easiest to see when one recalls that Kant’s Metaphysical Foundations represents a very particular kind of science of matter – a science which is in essence concerned with constructing pictures in the imagination. Kant’s philosophy of science requires such a construction of material pictures in order to bridge the gap between his transcendental philosophy and normal empirical science. Without them, we could explain neither how pure mathematics and the categories become binding in the realm of empirical experience, nor why the science of nature must be unified. In discussing both Hertz and Kant, it will be useful to keep in mind that Kant’s concept of matter is exceedingly general: matter is whatever is involved in an intuition which does not belong to its form, and so sensations qualify as matter. The pure science of matter which Kant develops in the Foundations is concerned with matter in its most abstract sense, that is, as the content of any possible intuition or product of the imagination. Obviously this definition is in close accordance with Hertz’s pecuniary model. In the Introduction to the Metaphysical Foundations, Kant argues that all natural science, if it is to be apodictic knowledge [Erkenntnis], and not merely so-called knowledge, must contain an a priori part. For if all the concepts and laws in a body of knowledge were arrived at empirically and inductively, the science in question would not be a rational science. And so it follows that there must be transcendental principles at the foundations of the natural sciences, principles which are on the one hand metaphysical, in that they concern the relations between pure concepts of the understanding, and on the other mathematical, because they relate to the construction of these concepts in intuition. However, since the natural sciences are also concerned with existing things, there must also be metaphysical principles which specify the kind of existence one is dealing with, which will be either the soul, for psychology, or corporeal matter, for physics. This demand entails that there be a special metaphysics for physics itself, which bridges the gap between the transcendental principles of the sciences, and the empirical laws which make up the body of physics. This metaphysics must relate the concept of matter to our intuition of space. Now, as Kant emphasises, the properties of matter which are successively investigated in the Metaphysical Foundations are necessarily empirical. Whether matter is defined as the movable in space, as that which fills a space, or as that

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which has a moving force (to run through Kant’s successive definitions of the concept), nothing can guarantee that things satisfying these definitions must exist. For physics is concerned with the material world, and the material world is that given to us in sensation. Concepts that have to do with possible sensation are, in turn, empirical concepts, and nothing guarantees their metaphysical, as opposed to merely logical possibility. At the same time, however, the propositions developed out of these concepts by means of metaphysical analysis are apodictic. They pronounce neither upon the various kinds of matter or forces that do in fact exist, nor upon the exact form that physical laws might take. In order that the application of mathematics to the science of bodies, which can only by this means become a natural science, may become possible, one must first develop the principles of the construction of those concepts which belong to the possibility itself of matter. Therefore one will have lay down a complete analysis of the concept of matter, which is a business of pure philosophy. It w i l l need to avail itself of no special experiences, but only of that which it itself finds in particular (although in themselves empirical) concepts as they pertain to pure intuitions in space and time – that is, according to laws depending essentially on the mere concept of nature. This complete analysis of the concept of matter is thereby an actual metaphysics of corporeal nature.3

So we get the following equation: A priori principles + Empirical Concept(s) of Matter = Metaphysics of Corporeal Nature. The metaphysics of corporeal nature, in turn, when it is combined with specific data concerning the observed behaviour of natural systems will yield physics as we know it. A priori principles (pure forms of the understanding, time, space)

+

Empirical concept(s) of matter (phoronomic, dynamic, mechanical)

=

Metaphysics of corporeal nature

Metaphysics of corporeal nature

+

Empirical laws

=

Natural science (Newtonian physics, ...)

One way to think of the place of applied metaphysics in Kant’s system is to regard it as a schematism of empirical concepts. It resembles the schematism of the first Critique in its linking of the categories to pure intuition. But whereas in the schematism we move solely within the realm of the a priori – pure forms of the understanding are “constructed” by connecting them with the pure a priori intuition of time – in the Metaphysical Foundations pure empirical material concepts, such as “a movable something in space,” are constructed by connecting them with the intuitions of both time and space. In schematism itself, Kant contrasts the schemata of pure concepts of the understanding to schemata of sensual concepts, and explains their differing relations to what he calls “pictures” [Bilder]. A sensual concept is a rule for drawing [verzeichnen] arbitrary pictures

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39

in the imagination. The schema of a sensual concept is the product of the pure imagination by means of which such pictures are at all possible, and which furthermore connects the pictures to the concepts they characterise [bezeichnen]. The schema of a pure concept, on the other hand, is a pure synthesis of the productive imagination according to a rule for generating a conceptual unity – it can never yield a picture, for it has no sensual content.4 To make this somewhat easier to visualise: the concept of a dog is a rule for producing various images of four-legged animals; the schema of the concept is the operation of the imagination in accordance with the rule – the set of drawing operations which lead to pictures of dogs; and a pure schema is one of the operations underlying the latter, one of the operations involved in acts of drawing generally, one might say. Just as general drawing techniques do not produce a picture of anything, so the schema of a pure concept does not produce a picture in the imagination. This can only be the case once an empirical sensual concept is given as a rule. According to this division, the Metaphysical Foundations describes the schematisation of the empirical concept of matter. Such a schematisation determines the set of images of material systems which are in accordance with that concept. These are the most general images of the natural world that we can produce, and any particular representation of a physical system will be a refinement of a picture drawn from that image bank. These pictures are necessarily mathematisable, for they have been schematised within the extensive magnitudes of space and time. Furthermore, they connect to experience by means of the categories and pure intuition, which are the conditions of the transcendental unity of apperception, thus of any objective experience we may have, whether scientific or everyday. Finally, the requirement that all special sciences partake in the metaphysics of corporeal nature – which means nothing more than that they will draw their images from that image bank – entails that science will also take the form of a unified mathematical theory: each scientific theory and its images will be a more determinate, filled-in version of the basic schemes given by Kant’s corporeal metaphysics. With these points in mind, let us return to Hertz’s Constitution of Matter. 3. HERTZ’S ON THE CONSTITUTION OF MATTER

In the opening lectures of this book, Hertz makes the first documented use of his picture-theory of science. The theory is introduced to deal with a fundamental paradox confronting us when we try to think about the microscopic world, for instance when we describe heat or elasticity by means of an atomic theory. The paradox is straightforward: we cannot use the atomic conception without ascribing properties to atoms – properties which, by definition, the atoms cannot have. All these properties will be taken from our experience of the macroscopic world – they will be sensual properties, Hertz argues - but atoms are by definition not sensible. “Every sensual representation of the atoms includes an absurdity, every

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DAVID JALAL HYDER

translation of sensual properties of matter onto atoms contains a logical error. But what then remains?” Hertz answers that ... there is always something left over once we have cancelled out all thought. There remains a system of conceptually defined magnitudes, which are connected among themselves and to the macroscopic properties of matter by means of rigorously defined mathematical relations; even if it is not allowed to take the latter at face value and to ascribe them imaginable meanings [Bedeutungen], they still retain their value as ancillary magnitudes to those relations.5

Now, Hertz goes on to argue, one might take a very strict view of the matter, and choose to describe perceptual facts in the simplest possible manner, rejecting everything beyond the phenomena as a fiction. This is, he observes, the opinion of many physicists regarding the theory of the constitution of matter. The only constraints placed on our concept of matter from this point of view are that they be logically consistent, and that they lead to simple equations. But Hertz rejects this phenomenological approach, arguing that although physics has every right to go this road, it has no necessary superiority. For every intuition of a concept, whether in everyday life or in scientific practice, has properties that do not actually hold of things in themselves. Not only is there is no principled difference between a phenomenological approach and one in which in which we imagine microscopic entities, we have no alternative to constructing images of our scientific concepts. Even if we try to eliminate as much as possible from these images, a core will remain, which contains the essential properties with which we are concerned. [These] are not false representations, but rather the conditions of representation itself; we cannot remove them and replace them with better ones, rather we must either add them in or give up on all representations in this field.6

Of course this immediately raises the question as to precisely which properties are essential to our concept of matter. Hertz devotes the first chapter of the second part of The Constitution of Matter to this question, treating at length the prime candidates for metaphysically necessary properties – extension, movability, impenetrability, and indestructibility – while referring in passing to the Metaphysical Foundations. The one metaphysical property obviously missing from this list, namely force, he treats at length in the preceding chapters, in what can only be described as a lengthy attack on the coherence of this concept. There, Hertz goes so far as to suggest that all actions at a distance, including gravitation, are best represented by means of a field theory, and that such a field should itself be understood as propagating in time. 7 Hertz characterises his discussion of the various properties of matter as the search for a “fixed pole,” a property which we must ascribe to matter in order for it to be suitable for picturing the world.8 Despite the obvious parallel to Kant’s undertaking (for all of these properties are analysed in the course of the Metaphysical Foundations), Hertz’s result is somewhat different from Kant’s. He concludes that all of these properties are a

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41

mixture of empirical and a priori components, and that none of them can be taken as constitutive of our concept. He concludes with the lengthy analogy to paper money outlined above, which can only be interpreted as a form of conventionalism. The specific form we give to our concept of matter does not essentially affect the meaning of the scientific pictures which employ that concept; however, it is a grave error to project the properties that we have given it onto the things to which it refers. What is essential to these pictures, he concludes, is that they allow us to represent the mathematical relations between macroscopically observable magnitudes. It follows, a fortiori, that only the spatial and temporal relations within these pictures are essential, since only they can be the source of mathematical relations. 4. CONSTRUCTIONS

AND

PICTURES

IN

ELECTRIC WAVES

As we saw, Hertz first introduced the picture-theory while considering atoms. How, he asks, and under what circumstances, are we justified in thinking about the microscopic world? The question – and its answer – are of great generality. But Hertz posed it at a specific moment in his research. At the time he gave his lectures on the constitution of matter, he was struggling to develop a picture of Maxwell’s theory of electromagnetism which he could use to guide his experimental work. He describes that struggle in the introduction to his Electric Waves as holding between four competing pictures of electromagnetic phenomena, ranging from one based on pure action at a distance to a pure field-theoretical approach, in which all action at a distance is replaced by the polarisation of the ether, and in which the bearer or original cause of the actions at a distance (namely the electric fluid) is eliminated completely.9 In this context, the questions he raises in the lectures concerning the status of basic properties of matter, concerning the existence of the ether and the legitimacy of action at a distance are not merely of philosophical interest. They are questions concerning the legitimacy and implications of the basic elements of the competing pictures. Hertz had to ask himself whether it was legitimate to regard electricity as a substance which exerted a force; he had to inquire into those characteristics which could be legitimately ascribed to the ether; indeed, he had to ask himself whether the very notion of an electric force was legitimate, or whether it ought instead be eliminated in favour of ether polarisation. At the same time, these questions were directly connected to the legitimacy of Maxwell’s electromagnetic equations. For although Hertz, like his mentor Helmholtz, believed that Maxwell’s equations were phenomenologically valid, this conviction did not tell him how to apply those equations in all cases. In the absence of a picture giving them a physical meaning, the mathematics could not be unambiguously applied. Hertz described this quandary as follows in the introduction to Electric Waves:

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DAVID JALAL HYDER

In my experiments, I could not ... be guided by Maxwell’s book directly. Instead I let myself be guided by the works of Helmholtz, as is clear from the account of the experiments. But in the special limiting case of Helmholtz’s theory which leads to Maxwell’s equations, and to which the experiments lead, the physical meaning of Helmholtz’s theory unfortunately disappears, as it indeed generally disappears, if one wants to disregard action at a distance. I thus tried to construct to myself the indispensable physical representations without contradiction [Ich versuchte deshalb mir die unentbehrlichen physikalischen Vorstellungen widerspruchsfrei selbst zu konstruieren ...] by departing from Maxwell’s equations, but also by simplifying Maxwell’s theory as much as possible by eliminating or simply leaving out all those elements which I didn’t understand and which were dispensable, in that they could have no influence on possible experiences. 10

Hertz’s method was therefore to pare down the concepts he had inherited from Helmholtz and Maxwell by constructing their physical concepts without contradiction. He presents the results of this construction in two papers from 1890, the first on the electrodynamics of stationary bodies, the second on that of moving bodies.11 He describes the necessary “intuitions” of the first paper as consisting in positing a single directed magnitude for each point in space, whose changes depended only on the values of the immediately adjacent magnitudes, thereby excluding all actions at a distance. 12 In the introduction to the second of the papers, he asks whether these intuitions can also be used to model the electrodynamic appearances of moving bodies, and concludes that this question cannot be definitively answered without an understanding of the connections holding between the motions of ponderable matter and the motion of the ether. 13 In short, what he arrived at was a purified form of Maxwell’s theory, in which all one has is a polarised medium. Regarding the ether, he observed that within the intuition he had developed, We regard ... polarisations as the only actual existents; they are both the causes of the movements of ponderable matter and of the remaining appearances, which cause us to regard the latter as being changed. We defer an explanation of the essence of polarisation, its constitution [Zusammenhang] and its effects, or we look for it in mechanical hypotheses.14

5. THE PRINCIPLES

OF

MECHANICS

Thus the gap in Hertz’s picture of electromagnetism was occupied by the ether: How are we to imagine its polarisation? More generally, how are we to conceive of what Hertz had called in The Constitution of Matter the “modification of space” 15 [ Veränderung des Raumes] which produce those appearances we subsume under the concept of distance forces? In those early lectures, Hertz had identified this as one of the tasks of the science of the constitution of matter, arguing that ”if there is a change in a space [Besteht in einem Raume eine Veränderung] , we cannot conceive of this otherwise than by there being something

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which is changed, and which we can call matter.” 16 To fill the gap one would need a picture of these hidden material systems. Hertz’s last book, The Principles of Mechanics Presented in a New Form,17 attempted to do just this. The Principles of Mechanics achieves its end by positing a class of unseen systems composed of “hidden masses.” Within a system of masses, the hidden ones are connected to the observable ones in such a way that the total energy of the system remains constant: all physical systems obey a single empirical law, which Hertz termed his “Fundamental Law.” Motions in which the kinetic energy of a system appears to change as a result of the action of forces are accounted for by referring the lost and restored energy to the motions of the hidden masses. In Hertz’s system, all energy is kinetic and all connections between mass-points are rigid, so that no causes are required to explain why a mass-point takes the path it does. Quite aside from the physical picture it presents, the Principles of Mechanics is also structured in a most peculiar fashion. The work is divided into two books, the first of which develops a geometrical account of the motions of systems which is then applied to actual experience in the second book by means of a series of coordinative definitions and the fundamental law. The propositions of the first book, Hertz emphasises repeatedly, are purely a priori, being either definitions or following from the laws of our intuition and thought. These propositions comprise a generalised analytic geometry of n-dimensional space, as well as a peculiar definition of matter, which defines the latter as consisting of massparticles, each of which is “a characteristic [Merkmal] by means of which we unambiguously correlate a definite point of space at a given time to another definite point of space at each different time.” 18 In the second book, the propositions of the first book are given an experiential content by means of coordinative definitions, and the class of what Hertz calls the “thinkable motions” of systems described in the first book is constrained to those of “natural motions,” which are those motions of systems which are consistent with the fundamental law. In other words, the a priori picture of material systems, considered as collections of paths in space-time, which is developed in the first book is filled in to yield an empirical picture in the second book. This picture is a picture of physical experience as we know it so far. So we get the following equations: Generalised geometry (Geometry of systems of points)

+

Definitions of material systems (mass-particle, -point, system of masses)

=

A priori kinematics of systems of masses (Book 1)

Book 1

+

Fundamental law, Coordinative definitions (Book 2)

=

Empirical system of mechanics

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Book 1 is the focus of our interest at present, for it comprises the same basic elements, and fulfils the same function as Kant’s metaphysics of corporeal nature: it contains pure mathematical principles depending on our notions of space and time, and on strict “phoronometric” definitions of matter, i.e. definitions that appeal to nothing beyond our subjective correlation of one point in space with another at different points in time. At the same time, Book 1 of the Principles corresponds well to the philosophical part of Hertz’s science of the constitution of matter. It seeks to give a form to the basic signs of our scientific pictures which makes them suited for “regulating our dealings” with the external world, without, however regarding them in their signifying relation, which is given only in Book 2. Taken together, Book 1 and Book 2 provide the means of picturing any system we might find in nature, so long as we can draw in the necessary details, while distinguishing rigorously between the apodictic and empirical parts of this picture. 6. C O N C L U S I O N

I said by way of introduction that even where Hertz disagreed with Kant, he used Kantian methods to prove his point. We are now in a position to see how this is so. Hertz claimed that his Principles allowed one to reconstruct the full content of mechanics without appealing to the notion of force. In doing so, he aligned himself with physicist-philosophers like Fechner and Kirchhoff in denying the claims of “dynamicists,” among whom one may count the young Helmholtz, who argued with Kant that the concept of force was in some sense essential to our concept of matter. As we saw, Hertz was already leaning strongly in this direction as early as 1884, when he held his lectures on the constitution of matter. To prove that this claim was false, he offered an axiomatic reconstruction of mechanics employing only a kinematic notion of matter as “something movable in space”, along with a priori geometrical propositions. Building on this foundation, Hertz was able to construct a “picture” of mechanics without appealing to the notion of force. From the point of view of Kant’s Metaphysical Foundations, Hertz’s Principles uses an exclusively “phoronomic” definition of matter, and Hertz refuted the claim that the concept of force is necessary to empirical science by completing Kant’s constructive project without appealing to this concept – without moving on, one might say, to the construction of either “dynamical” or “mechanical” concepts of matter as Kant himself had done. However, as Simon Saunders has argued, Hertz was deceived in his belief that his picture of mechanics was equivalent to those it was to replaced, because it failed to give criteria for physically isolating inertial frames.19 Hertz overlooked, in other words, Kant’s fundamental ground for claiming that a move from phoronomy to dynamics and mechanics (both in Kant’s sense) was necessary, namely that only in making that move could experience become fully determinate and intersub-

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jective, and in consequence he failed to see that his alternative construction of the concept of matter – his alternative picture of fundamental natural science20 – did not so much refute Kant, as vindicate him.

NOTES

*

This paper develops the philosophical portion of a short piece on Hertz’s Die Constitution der Materie that I wrote together with Heinz Lübbig (David Hyder and Heinz Lübbig, “Questions Suspended in the Ether,” in Nature, Vol. 404, No. 6775, 2000, pp. 223-224). Aside from a great debt to Prof. Lübbig for our discussions while working on that piece, I was given advice on my reading of Kant by Konstantin Pollok. Jesper Lutzen made a number of incisive comments on an earlier version of the present paper, and was so kind as to show me portions of the manuscript of his forthcoming book on Hertz’s Principles, to be appearing under the title Heinrich Hertz’s Principles of Mechanics. Along with his earlier Denouncing Force; Geometrizing Mechanics. Hertz’s Principles of Mechanics. Copenhagen: Københavns Universitet Matematisk Institut 1995, these helped me to achieve a balance between science-historical and philosophical concerns.

1.

Heinrich Hertz, Die Constitution der Materie. Berlin: Springer 1999. With the exception of this new and untranslated text, all citations of Hertz’s works in the following are from the German edition of his collected works. The reader may be helped by the cross-referencing of the various editions, in English and German, of Hertz’s works given in D. Baird, R.I.G. Hughes, and A. Nordmann (Eds.) Heinrich Hertz: Classical Physicist, Modern Philosopher. Boston Studies in the Philosophy of Science, Vol. 198. Dordrecht: Kluwer 1998. p. 307. Ibid, pp. 117-118. This and all subsequent translations from German texts are mine. Immanuel Kant. Metaphysische Anfangsgründe der Naturwissenschaft. Akademie edition IV.472, lines 1-12. Emphasis in the original. Cf. Immanuel Kant, Kritik der reinen Vernunft, B179-180. Hertz, Die Constitution der Materie, loc. cit., pp. 34-35. Ibid., p. 36. Ibid., pp. 61-62. Ibid., p. 116. Heinrich Hertz. Untersuchungen über die Ausbreitung der elektrischen Kraft. Gesammelte Werke von Heinrich Hertz. Vol. 2. Leipzig: Johann Ambrosius Barth 1894, p. 21ff. Ibid., p. 22. Heinrich Hertz, “Über die Grundgleichungen der Elektrodynamik für ruhende Körper” and “Über die Grundgleichungen der Elektrodynamik für bewegte Körper” both in Hertz, Untersuchungen über die Ausbreitung der elektrischen Kraft, loc. cit. pp. 208-255, 256-285. Hertz, “Über die Grundgleichungen der Elektrodynamik für ruhende Körper”, loc. cit. p. 209. Hertz, “Über die Grundgleichungen der Elektrodynamik für bewegte Körper”, loc. cit. p. 257. Hertz, Untersuchungen über die Ausbreitung der elektrischen Kraft, loc. cit., p. 27. Hertz, Die Constitution der Materie, loc. cit., p. 62. Ibid. Emphasis in the original. Heinrich Hertz. Die Prinzipien der Mechanik in neuem Zusammenhange dargestellt. Gesammelte Werke von Heinrich Hertz. Vol. 3. Leipzig: Johann Ambrosius Barth 1910. Heinrich Hertz. Die Prinzipien der Mechanik, loc. cit., p. 54. See Jesper Lutzen, “A Matter of Matter or a Matter of Space?” in Archives Internationales d’Hisloire des Sciences, Vol. 49 No. 143, pp. 103-121, for a detailed discussion of Hertz’s concept of a mass-particle. Simon Saunders, “Hertz’s Principles”, in D. Baird et al. (Eds.) Heinrich Hertz, loc. cit., pp. 123154. See above all the discussion of Kant, p. 146.

2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

12. 13. 14. 15. 16. 17.

18. 19.

46

20.

DAVID JALAL HYDER

Cf. Hertz, Die Prinzipien der Mechanik, loc. cit., p. xxix, “All physicists are unanimous that it is the task of physics to reduce all appearances of nature to the simple laws of mechanics.”

Fachbereich Philosophie Universität Konstanz D-78457 Konstanz Germany [email protected]

II.

MORITZ SCHLICK

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HUBERT SCHLEICHERT

MORITZ SCHLICK’S IDEA OF NON-TERRITORIAL STATES

1. THE DOCUMENT

In 1952, a small booklet by Moritz Schlick appeared. It was entitled “Natur und Kultur”, and was edited by Josef Rauscher, a former student of Schlick. Its preface identifies it as an unfinished manuscript of what Schlick had intended to become his main work. It may have been written around 1935. Schlick died in 1936. As far as I know, the booklet has not been translated into any other language. I am not sure as to how much Rauscher manipulated the text, but I think that it can basically be regarded without suspicion. The booklet features Schlick’s thoughts on topics like culture and morality, the concept of fate in history, war and military service and other political problems. Although it is only a draft, and thus not ready for publishing, it shows a rather unknown side of Schlick. This side, one would be forced to say, does not really fit with the usual description of Logical Positivism. None of the key terms of Logical Positivism like meaning, verification, falsification, basic sentence, proposition, the possibility of feeling other persons pain, etc., appear in the booklet. Here we have, as it were, a Wittgenstein-free Schlick. Of course, Schlick was not schizophrenic; he simply was more of a philosopher than the standard historiography of the Vienna Circle and Logical Positivism seem to claim. 2. NEGATIVE ASPECTS OF THE STATE

In the following I will only focus on a few remarks made by Schlick on the state. The term “remarks” must be stressed, because the whole issue was never really elaborated upon by Schlick. Schlick does not use the term “social contract”, but this concept obviously forms the backdrop for what he is saying. As is well known, this term is used to theoretically reconstruct what rational people could or would do in order to overcome a completely anarchic situation, a situation which usually is described as unsafe, poor, and miserable. According to this theory, rational people would agree to establish some kind of rulership or sovereignty by signing a “social contract”. Thus a state is created in order to guarantee peace and security. However, as Schlick writes, 49 F. Stadler (ed.), The Vienna Circle and Logical Empiricism: Re-evaluation and Future Perspectives, 49–61. © 2003 Kluwer Academic Publishers. Printed in the Netherlands.

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(1) There is nothing in our European civilization that causes more grief than the state. Under it we suffer most. Since there is nothing wrong with the original idea of the state, i.e. an association for help and protection through reasonable institutions, the mistake must lie in its execution … The first question would be: Who participates in the unification? According to which principle shall the selection be made? (p. 67)

This is an unusual and surprising question. According to the standard version of the social contract, such a question does not arise at all. There is no selection to be made – the whole population, all the people together, agree to instate a certain government. Should somebody disagree, then – at least in some constructions – he would be forced to give his consent, or else he would be considered to be an enemy of the state. The state rules over a certain territory; everything and every person within it, even unborn children and babies come under the state’s control. On the other side of the border, there are other states, which means potential enemies. From the very beginning, the state plays a double role. It guarantees peace within its territory and prevents civil war, while at the same time preparing for war outside its precincts, against other states. But this latter feature of every state is not discussed in the theories of social contract. Schlick makes a bitter remark about civil wars, which to Hobbes, for example, were the most terrible of all political situations: (2) Terrible as they are, one has to acknowledge the fact that civil wars usually do not claim as many victims as wars between states with separate territories have, i.e. between hostile countries. This is an argument to not separate contradictory tendencies … by space, but to mix the enemies. Then the unavoidable balance will lead to only minor catastrophes, (p. 101)

I will let the last sentence stand for a moment without commenting on it. However, it is probably true, as a “body-count” would reveal, that the number of people killed during “official”, “regular” wars conducted by states is much higher than those killed during civil wars. From this point of view, the whole ideology of a social contract is highly problematic. But let me come back to the last sentence of Schlick and his idea of separating hostile groups in space.

3. THE SOCIAL CONTRACT AND TERRITORIAL STATES For historical reasons, it is obvious that states are defined by a territory. But is this the only possibility? As Schlick says, states are constructions that are made by us and can be changed by us, and we should make these constructions as safe and rational as we can. That states start wars against others, is not contained in the idea of a social contract. It is rather a degeneration of that idea. Unfortunately, this degeneration is the most common and – so to speak – normal thing in history. As we shall see in a moment, Schlick looked for an alternative conception of the state in order to prevent such degeneration.

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There are still other difficulties in the usual theory; but in one respect the standard theory of a social contract comes quite close to political reality. In order to give the state a moral justification, free persons must consent to it. Yet even within contractarian theories, there is not much room for freedom of decision. There is only one state that can be established, and people can only say yes to it. Those who say no become outcasts. Once this is done, it is very difficult to revise this decision; the only way to do it would be by emigration. Practically speaking, the vast majority of all people on this earth become citizen or subjects of their state by birth and must remain in the state where they have been born. 4. AN ALTERNATIVE: SCHLICK-STATES

At this point, Schlick introduces an alternative kind of social contract, which allows people to make a real choice between several possibilities, a choice that later also can be revised without great problems. He argues: (3) According to our notion of the state, it is an association with the purpose of protecting all vital necessities. This conception leaves it completely open whether the boundaries of the state – i.e. the group of citizens of the state – are determined by living together on the same territory, or by some other principle. (p. 101)

It is not a priori necessary to define a state as sovereign over a certain territory. A state could also be defined as a sovereign over a certain group of human beings. In this case, several “states” could coexist within the same territory. Schlick tries to describe such a situation as follows: (4) Suppose that the separation according to political convictions replaces the separation by geographical states. In such a case there would be no countries in the usual sense, but political organisations, the members of which would live scattered over all continents. Each of these invisible communities could have its own laws and costumes, its courts, police, and state form. There could be invisible republics and monarchies, but the presidents and kings would not rule over territories, but only over such people as voluntarily belong to their state. Since human convictions can change, it follows from the very principle that one can at any given time move from one organization to another. (p. 102/3)

Let us refer to this as “Schlick’s Principle” and “Schlick states”. Clearly, all this is utopian thinking. The question is, is it an interesting utopia? Is it worth consideration? It is a theoretical reflexion about how modern, rational people, after having been through all the negative experiences mankind has had with territorial states, would or should construct their state – or rather, their commonwealth of states. Unfortunately, Schlick does not provide any examples from history. Perhaps he thought that his ideas were too far removed from reality. Therefore, we have to look for examples ourselves.

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One example that comes close to Schlick’s ideas is that of the Roman Catholics. It is a large transnational, transterritorial group and everybody is invited to join the group. Theoretically, everybody belongs to this group only by his free decision, not simply by birth, and everybody is free to leave the group at any time. Theoretically, this group has its own civil law, especially for marriage and divorce, rules stating what forms of sexuality, birth control or genetic engineering are allowed or forbidden, what books are recommended and those that have to be burned, what days allowed for work, certain meat-eating days with fish as a substitute on other days, etc. Those who belong to this community are prepared to obey the whole set of these prescriptions wherever they live. This is done, more or less, without the help of the police. Even penalties are paid without control. One need only think of the exercises a believer has to do as a compensation for his sins after confession. Catholicism has a well-known transnational organization, including an absolute sovereign, and it has millions of followers all over the globe. It does not, however, claim a territory of its own, except for a very small piece of land called the Vatican state. For many reasons, of course, this is not a perfect illustration of Schlick’s ideas. It is enough to mention the notorious intolerance of the Roman church. During its heyday, it never tolerated other religions on the same territory and persecuted those who wanted to secede from the one and only true church. This attitude openly contradicts Schlick’s ideas. A better example for Schlick’s ideas is the phenomenon called “Diaspora”, especially as it has been interpreted by the British historian Arnold J. Toynbee (see Toynbee 1966). The Greek term “Diaspora” means dispersed, scattered. It refers to communities scattered over a large area, even over the whole globe. A typical example are the Jews, yet there are many other groups, like the Armenians, or perhaps the Bahai. “A diaspora is in a minority locally, wherever it may be. At the same time, a diaspora, unlike a local community, is ubiquitous” (cf.p.81). Toynbee called the former Ottoman empire an association of diasporas, each of which was distributed over the whole empire and none being in exclusive possession of a local province (Toynbee 1966, p. 84). I have no idea as to whether Toynbee’s interpretation is plausible. It does, however, point to an interesting possibility. The Ottoman empire, he says, was like a shot-silk robe. Due to later nationalistic ideologies, it was cut into more or less monochrome small pieces, which have been rewoven together into a coarse patchwork. If somebody wishes a more recent illustration, he need only compare a map of the Balkans from 1950 to a present-day one. The phenomenon of diaspora played an important role even in ancient times. Toynbee even writes that diasporas are coeval with the Sumerian city-states. However, as Toynbee believes, that role could become much more prominent in modern times, as geographical distances cease to be important due to modern communication technologies.

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Schlick does not want his groups or states to be defined by inborn and timeless properties like race or language, or by an intolerant religion that claims to be the only possessor of truth and salvation, but only by rational decisions of adult people. In Schlick’s model, one subscribes to a state as one would to a healthinsurance company. If it does not fulfil one’s expectations, one can change to another one. It might be costly, it might entail practical problems or inconveniences, but in principle it is always possible. Toynbee and Schlick shared the same basic interest in ensuring world peace. Both considered the existence of traditional local states to be something antiquated and dangerous. 5. THE MINIMAL WORLD STATE

Schlick’s plurality of states on the same territory, even if we remain on an utopian level, is riddled with numerous practical problems. He nevertheless thinks that they can be solved: (5) However, such a situation would only be stable, if there were specific rules determining the mutual relations between the members of the different organizations. (I purposely do not say: between the organizations themselves.) One should have agreed upon a minimum of supranational or international law. If you like, one could say that this amounts to establishing a world state … This “world state”, however, would be very “diluted”; it would be constituted by very simple rules … It would by no means be difficult to establish such global rules. (p. 103)

I think it would by no means be easy, but it would be possible. Such a “world state” could not, for example, be dominated by one group or group-state, as was the case with all former multiethnic empires like the Ottoman or the Habsburg empire. In fact, in every federal system the organization of the central power and its relation to the single states is of the utmost importance. But let us leave this aside. What Schlick envisages is a kind of United States of the World, a federal system of government. Only the single states are not to be defined by geographical borders, but by people who by their free decision (and not just by birth) become citizens of their respective states. These people can live close to each other in a given space, or may be scattered over a vast area, like the Jews in a diaspora. Actually, Schlick prefers this case to the concentration of a group in one country or region. If a group were not concentrated in one territory like traditional nations, it would reduce the possibility of aggression towards other groups. Citizens of a Schlick state would share a certain common feeling and have a kind of basic sympathy towards each other, because they would all share the same basic political and moral ideals. Therefore it is a rationally justified sympathy, whereas traditional patriotism, i.e. sympathy for other people only

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because they happen to be of the same nationality, is not very rational. In our real world, the difference or discrepancy between nationalistic, territorial loyalty and the loyalty of diaspora-people toward their respective “diasporas” has often been noticed. It was, incidentally, one of the standard arguments for anti-Semitism, especially during wars. What is true is that for an aggressive state, a narrowminded local patriotism is much more useful than loyality towards an international community living in diaspora. Schlick speaks about a world state. This would be the simplest solution. In Schlick’s states without territory, no territorial conflict could ever arise. Even on a less utopian scale, Schlick’s idea makes sense. We may think of former Yugoslavia, which had clear borders and no territorial conflicts with its neighbours. According to Schlick’s principle, it was a mistake to break up this territory and hand it over to every nationality in a certain geographical area. Those who think that their nationality is the most important thing may form a state, but not a territorial one, and elect their own rulers and judges and educational system, etc. If they like, they can completely ignore other groups. But others, who have different political ideas, may form other political groups or states and live on the same territory as well. No group should be allowed to dominate another. No group has a right to any special aid or support from the common minimal state, with the exception that the safety of each group is guaranteed.

6. DESCRIBING SCHLICK-STATES IN DETAIL Schlick states should be made up of humans having the same political ideals, regardless of their language, colour or place of birth. Let us try to be more detailed. There could be a very socialist state and an extremely capitalistic one neighbouring each other. It is easy to imagine different groups sharing the same territory, and yet having quite different civil laws. There could be a state where divorce, birth control, abortion, human cloning, and euthanasia are allowed. This state could share its territory with a state that obeys the Pope. There could be a state where polygamy is the standard of family life, and even a Platonic state – I mean a state of homosexuals. There might be quite different practices for healthinsurance and pensions, for education and culture. Different economic systems for different people, even different monetary systems within the same territory or across the whole globe are not impossible, somewhat like different telephonecompanies. Everybody could choose the state in which he wanted to live. Those who like it, might be governed by a fascist state, or live under a religious dictatorship, while others would prefer a system of direct (i.e. non-representative) democracy. There could be multiethnic states and those with only a single ethnic group, all on the same territory. The main condition would be non-interference and free movement between the states at any given time. There could and should be peaceful competition between states in order to win more citizens, like a competition to win customers in a free market.

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I must admit that there is a certain element of anarchism in Schlick’s conception. But this serves to reduce the danger that goes with all traditional territorial states. It could also be an antidote to unlimited globalization. Schlick states are clearly related to political parties in democracies. One feels some sympathy for a certain party, but one can at any time switch to another party or even try to found a new one. The main difference is, if a party is in the opposition, its followers have to obey the law made by the ruling party. They have no chance of living as they see fit. It is quite possible for 49% of the population in a democracy to have to live according to the idea of a good life as is determined by the remaining 51 %. 7. A WAY TO PEACE. NATIONALISM

The starting point of Schlick’s utopian construction was the question of how to reduce the probability of wars between states. One of the main causes for conflicts and wars are quarrels and fights over territorial claims. If a state is not defined by a territory, territorial questions disappear. It is worth considering an application of Schlick’s principle to calming or solving conflicts that take place between more or less hostile groups within a state. According to Schlick, such problems should not be treated by separating groups, with each group in its own closed territory. Rather, one should mix them. Here he offers a combination of practical and moral arguments: (6) Again, the essential presupposition is that the members of the groups live intermingled, for as soon as there is a territorial separation, new interests and complications arise. (p. 103) Attempts at secession and isolation prevent peace and the development of an international morality. Morality is always a product of living together. (p. 107)

It is interesting to note that already Voltaire, the great philosopher of Enlightenment, proposed while writing on religious tolerance, a multiplication of the number of groups, in order to eliminate or, at least, reduce aggression and intolerance between hostile groups. In his famous “Philosophical Dictionary”, in the article on tolerance (in part I), he wrote: If you have two religions in your midst, they will cut each other’s throat; if you have thirty, they will live in peace (Voltaire 1972, p. 390). Voltaire’s favorite example was the peaceful development of Amsterdam, a city in which many different religions coexisted. Schlick did not speak about nationalism. But one can ask if the same methods could be used to reduce hatred, aggression and nationalistic hysteria. It is really tempting to interpret Schlick’s ideas in this way, i.e. to take them as a suggestion for solving problems of nationalism. It is obvious that he would have rejected any kind of “ethnic cleansing”; I think he also must have been against what was going on after the First World War, namely the establishment of all the national states in Eastern Europe. Schlick saw the problems clearly:

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(7) Living together on the same territory, taken to be the principle of belonging together, gives rise to all such evils which dog our divided world the most. (p. 97)

Today, the most realistic examples of several groups living together on the same territory are those of areas with ethnically mixed populations. The world is full of such places. Unfortunately, most of these examples do not serve to further Schlick’s ideals. If we look at former Yugoslavia, we are presented with a shocking counterexample, which makes Schlick appear extremely naive. As he lived in Vienna, the former capital of the multi-ethnic Habsburg empire, Schlick must have known of enough discouraging examples of several nationalities living together within the same territory. In fact, this empire broke into pieces because of nationalistic problems. Schlick cannot have been so blind. The only way to peace seems to be a complete separation of nationalities, a division of the countries into several ghettos, each surrounded by very high fences, like wild animals in a zoo. In the Middle East one can often hear the slogan “high fences make good neighbours”, but what is true is that they do not make neighbours at all. Schlick had quite a different view of politics. (8) What is so unnatural about our states are their boundaries. Every borderline in space is unnatural, because there is never any plausible reason for calling something good which the other side calls bad. (p. 104)

And Schlick repeats that separation, secession, isolation make it impossible for any kind of international morality to materialize. Morality grows out of living together. The more removed you are from others, the higher the fences are, and the less you learn to think about the others’ feelings and problems and to show consideration for them. There are a few examples more convincing than that of the Balkans. One could mention the island and state of Mauritius. As an island, it has no territorial problems with other states. And it is inhabited by a lot of different nationalities: Hindu, Tamil, Creole, Black, Indian Muslim, Chinese. At least till now, it has been a peaceful state. Another example, on a larger scale, can be taken from India. Here there are different religious groups living more or less within the same territory. But each group lives under its own specific laws, especially a personal law. Theoretically, people can also change their religion and move from one group to another. There is, of course, the federal state of India, regulating conflicts between the groups, which is a difficult and complicated task. And it is not clear how stable or unstable the whole construction is. Over the last few years it has often been said that there will never be peace as long as each nationality claims its own territorial state. How many territorial states must be established until there is finally peace in the Balkans? It is well known that most governments are against secessionist movements. When this question arises, the international community of states shares the attitude of the

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Roman church towards divorce: it is of no importance whether partners love or hate each other; the only separation that is allowed is by death. Allen Buchanan, one of the prominent authors on secession, is not quite as rigorous, but he also insists that nations should have a right to self-determination only under very restricted conditions – e.g., if otherwise they really are in danger of being exterminated. But “as such”, i.e. just because it is a nation, no nation should have the right to self-determination. (Buchanan 1996 p. 298) 8. THE RIGHT TO SELF-DETERMINATION

Can we put aside the right of national self-determination, including the right to secession, so easily? Is it not a fundamental human right? Does it not follow from the basic ideas of democracy? Who is entitled to tell nations what they have to do, and what they must not do? Who could call himself a good democrat, and yet object if the majority of a population in a plebiscite decides to secede from their present state and establish a new one, usually a smaller one? Yet the right to self-determination does not have a very good reputation. Even philosophers prefer to look at states as if states, once established, are eternally fixed. But this contradicts the most basic principles of liberalism. It follows from these very principles that any group should be given the right to secede from a state if this group does not want to live in it any longer, and if it wants to establish a new state. But even the most liberal writer (Beran, 1984) found it necessary to make some restrictions, saying that a group must be territorially concentrated if it is to be given the right to self-determination. Why? Because every secession causes territorial problems. Think, for example, of the USA: they could not easily be divided into a white state and a coloured state, because both groups would have to claim the whole territory and, as this author writes (Beran 1984, p. 24) “it is not practicable at present for two states to share legal sovereignty over the whole territory”. Nearly all arguments against a liberal interpretation of self-determination refer to territorial questions. Schlick wanted to introduce his own ideas at exactly this point. I think that Schlick would have agreed with all modern critics of an unrestricted, unlimited, universal right to self-determination, as long as this right means what it usually means – namely, territorial secession, new borders etc. If two nationalities want to exterminate each other, and each wants to occupy the whole territory alone, then – according to Schlick – one should not separate them. Territorial separation is the favoured method of every nationalism, but if all possible conflicts were to be solved simply by separating the hostile parties, our globe would soon be too small. Besides, it would create endless territorial claims and wars. It is because of these bitter, practical experiences that today many political philosophers deny the right to separation and secession. (See e.g. Moore, 1998). The biblical procedure “if you go right, I shall go left, if you go

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left, I shall go right” is a negation of morality; but what is worse, it will not lead to peace, because to the left and to the right are already other people. Moritz Schlick’s model offers quite a different solution. First, from a moral point of view the right to political self-determination should be granted to any nation. But Schlick’s perspective is much wider than that. To him, the right to self-determination should be acknowledged to any group, not only to those that define themselves as a nation. “What’s so special about nations?” , that they can ask for self-determination, asked Allen Buchanan (Buchanan, 1996) in a polemic argument. Schlick would agree, but draw a different conclusion. Schlick’s conclusion would be that not only nations, but any group of adult human beings must be given the right to self-determination, including the right to secede from an existing state and try to create a new state. Actually, history knows only few secessionist movements which were not nationalistic. But the first movement to have been called a “secession” was a social, not a national movement. Thrice (494, 449, 287 BC), so the story goes, did the Roman plebeians withdraw themselves from the city-state of Rome in protest against the behaviour of the upper classes. This behavior received the Latin name of “secessio”. During the first secession, in 494 BC, the plebeians literally left the city and went to a hill called mons sacrum outside the urban territory. In Schlick’s model, self-determination does not lead to chaos or war, because self-determination does not include an exclusive right over a certain territory. In contrast to territorial states, Schlick-states can be founded, changed or abolished without disturbing peace and justice. All groups or Schlick-states must live on the same territory, and no Schlick-state is allowed to dominate another. Each group gets its own government, but no group has a territory of its own. Only individuals, if anyone at all, are landowners. As no political group, no Schlickstate, governs a territory – they are all forced to live together on the same globe, or island, or continent. So they must find some sort of a modus vivendi.

9. CONCLUSION We should not forget that Schlick’s ideal states are not defined as nations or nationalistic groups, but by groups that share some more abstract, political or moral principles. He writes: (9) Will I not prefer a thousand times more to cooperate with a reliable Chinese of good character than with an egotistic, insincere European? (p. 99/100)

And by “cooperation”, Schlick means political cooperation. Let me summarize. Schlick anticipated, perhaps not fully consciously, an alternative solution to one of the most urgent problems of political philosophy of our own time. His

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proposals are even more progressive than most philosophers are today. He developed a model for practically unlimited self-determination which does not lead to all the problems associated with nationalistic territorial self-determination. In a nutshell, it also points to a reconciliation between globalization and individual political freedom. It might be surprising to find such utopian thoughts coming from the central personality of Logical Positivism. But if so, it means only that the usual, by now “canonical” historiography of the Vienna Circle is too one-sided. It could even mean that Schlick’s own interpretation of philosophy, as given in the first article of the journal “Erkenntnis” (Schlick 1930), was not a complete description of what he himself did. But all this does not present any great difficulty. There are, however, a few words in Schlick’s booklet which really are confusing within the framework of political philosophy. The text, in two different places (pp. 99-100 and 107), makes use of the religious term “civitas dei”, taken from St. Augustine. There Schlick states that race, religion, political conviction or profession are all not so important as a basis of a natural state, whereas (10) the only reliable basis is the character of humans, their moral qualities (not their “convictions”). People of good character, the kind and peaceful, belong together “by nature”; they form the invisible state of god, civitas dei. (p. 99/100)

“Belonging together” in this context can only mean: they should establish a state for themselves. And once more we read: (11) Only good will can be the ultimate principle of unification; the state that is established in this way is the true state of god, civitas dei … (p. 107)

Schlick here leaves it open what shall happen with the rest of mankind, with the vast majority of people, those who are of only average or less than average moral quality. I have no idea how to integrate such pseudo-religious, unpolitical remarks into Schlick’s political ideas. Maybe something went wrong during the editing, maybe Schlick wanted to make a stand against Kant’s statement that even a population of devils would be able to have a state, maybe it is only a shorthand for something more complex, or maybe Schlick was too much under the influence of Wittgenstein. I am unable to solve this riddle. So I shall leave it, together with my best wishes for the next ten years, to the Institut Wiener Kreis.

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REFERENCES Beran, H. (1984): A Liberal Theory of Secession, Political Studies 32, p.21-31. Buchanan, Allen E. (1991): Secession: The Morality of Political Divorce from Fort Sumter to Lithuania and Quebec. Boulder, Color., Westview Pr. Buchanan, Allen E. (1996): What’s So Special About Nations? in Couture, Nielsen, and Seymour (eds.): Rethinking Nationalism, Univ. of Calgary Pr., p.283-310. Moore, Margaret (edit.) (1998) National Self-Determination and Secession, Oxford UPr. Schlick, Moritz (1930): Die Wende der Philosophie,“ Erkenntnis” Bd. 1, p. 4-11. Schlick, Moritz (1952): Natur und Kultur. Aus den Nachlaß des Autors herausgegeben von Josef Rauscher. Humboldt-Verlag Wien-Stuttgart 1952. 125 pg. (Sammlung die Universität, Bd. 30). All quotations are translated from this edition; page numbers refer to this edition. Toynbee, A.C. (1966) : Change and Habit. The Challenge of Our Time. Oxford UPr. (German translation: Menschheit – woher und wohin? Plädoyer für den Weltstaat. Stuttg. 1969.) Voltaire (1972): Philosophical Dictionary, transl. Th. Besterman, Penguin Classics.

SCHLICK-ZITATE (1) In unserer ganzen europäischen Kultur … ist nichts, was dem Menschen größere Daseinsnot bereitet, als der Staat. An ihm leiden wir am meisten. Da nun an der ursprünglichen Idee des Staates – Zusammenschluß zu Schutz und Hilfe durch vernunftgeschaffene Institutionen – nichts auszusetzen ist, so muß der Fehler in der Durchführung der Idee liegen … Die erste Frage wäre: Wer nimmt denn an der Vereinigung teil? Nach welchem Prinzip findet die Auswahl statt? (S. 67) (2) … Bürgerkrieg … So schrecklich solche Ereignisse auch sind, so ist doch zu bemerken, daß sie ungleich weniger verlustreiche und blutig zu verlaufen pflegen, als Kriege zwischen räumlich getrennten Staaten, also zwischen feindlichen Ländern. Dies spricht wiederum dafür, daß man entgegengesetzte Tendenzen, … nicht auch räumlich voneinander trennen soll, sondern die Gegner untereinander mischen. Dann erfolgt der unvermeidliche Ausgleich in geringeren Katastrophen. (S. 101) (3) Unser Begriff vom Staate ist: Zusammenschluß zum Schutz aller gemeinsamen Lebensnotwendigkeiten. Bei dieser Definition bleibt es gänzlich offen, ob die Grenzen des Staates – das heißt: der Umkreis der Bürger, die zu ihm gehören – durch örtliches Zusammenwohnen bestimmt werden, … , oder ob die Trennung durch ein anderes Prinzip erfolgt. (S.101) (4) Stellen wir uns einmal vor, daß die Trennung nach politischen Überzeugungen an die Stelle der Einteilung in geographische Staaten träte. Dann gäbe es keine Länder im üblichen Sinn, wohl aber politische Organisationen, deren Mitglieder durch alle Erdteile und Gegenden zerstreut ihre Wohnsitze hätten. Jede dieser unsichtbaren Gemeinschaften könnte ihre eigenen Gesetze, ihre eigenen Sitten, ihre eigene Rechtspflege und Exekutive und auch ihre eigene Staatsform haben. Es könnte unsichtbare Republiken und Monarchien geben, aber die Präsidenten und Fürsten würden nicht über Territorien herrschen, sondern nur über Menschen, die ihrem Staat freiwillig angehören. Denn da die Über-

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zeugungen des einzelnen sich ändern können, so liegt es im Prinzip der Sache, daß der Übertritt von einer Organisation zur anderen jederzeit stattfinden kann. (S. 102/3) (5) Allerdings wäre eine solcher Zustand nur dann von innerer Festigkeit, wenn es auch besondere Regeln für das gegenseitige Verhältnis zwischen den Mitgliedern verschiedener Organisationen (ich sage absichtlich nicht: zwischen den Organisationen selbst) gäbe; man müßte sich also auf ein gewisses Minimum von überstaatlichem oder interstaatlichem Recht geeinigt haben und, wenn man will, kann man sagen, daß dies eben auf die Konstitution eines einzigen Weltstaates hinausliefe … Der ,,Weltstaat“ wäre unter den gedachten Umständen sehr verdünnt, er wäre durch relativ sehr einfache Regeln konstituiert, … Es wäre durchaus nicht schwer, derartige Weltstatuten aufzustellen. (S. 103) (6) Die wesentliche Voraussetzung ist allerdings wieder, daß die Mitglieder der Gruppen miteinander vermischt leben, denn sowie eine räumliche Trennung eintritt, entstehen neue Interessen und Komplikationen. (S.103). Streben nach Abtrennung, Isolierung verhindert die Entwicklung eines Zustandes friedlichen Zusammenlebens, es verhindert die Entstehung einer Völkermoral. Sittlichkeit ist immer das Produkt des Zusammenlebens. (S. 107) (7) Wenn das räumliche Beisammenwohnen zum Prinzip der Zusammengehörigkeit gemacht wird, so entstehen alle jene Übel des Gegeneinander, unter denen die in Staaten zerstückelte Welt am meisten leidet. (S. 97) (8) Das Unnatürliche an unseren Staaten sind ihre Grenzen. Jede räumliche Grenze ist unnatürlich, weil es nie einen vernünftigen Grund gibt, daß auf der einen Seite gut heißen sollte, was auf der andern schlecht heißt. (S. 104) (9) Werde ich nicht tausendmal lieber mit einem Chinesen gemeinsame Sache machen, den ich als zuverlässig und von gütiger Gesinnung erkannt habe, als mit einem Europäer, der unaufrichtig und selbstsüchtig ist? (S. 99/100) (10) die einzig zuverlässige Grundlage ist der Charakter der Menschen, ihre ethischen Eigenschaften (nicht ,,Überzeugungen“). Die Menschen von Charakter, die Gütigen und Friedfertigen, gehören ,,von Natur“ zusammen, sie bilden die unsichtbare Civitas dei … (S. 99/100) (11) Der gute Wille allein kann letztes Prinzip des Zusammenschlusses sein; der so gebildete Staat ist die wahre Civitas dei … (S. 107)

FB Philosophie Universität Konstanz, Fach D17 D 78457 Konstanz Germany [email protected]

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MASSIMO FERRARI

AN UNKNOWN SIDE OF MORITZ SCHLICK’S INTELLECTUAL BIOGRAPHY: THE REVIEWS FOR THE “VIERTELJAHRSCHRIFT FÜR WISSENSCHAFTLICHE PHILOSOPHIE UND SOZIOLOGIE” (1911-1916)

Moritz Schlick’s intellectual biography constitutes a very interesting or – more precisely – unavoidable issue for the scholarship of the history of logical empiricism. Nevertheless, it still lacks extensive inquiry and has seldom been studied1, whereas in the last years some research on the leading figures of the movement such as Neurath, Carnap and Reichenbach has begun. At least count, there is a lot of material which will enable us in the near future to satisfy the desideratum of biographical reconstruction2. And yet this exciting argument by no means signifies simply archeological research. On the contrary, Schlick’s scientific and philosophical development represents a paradigmatic aspect of the Vienna Circle: it exemplifies in the best way both the intricate roots of the “scientific worldview” and the relationship between continuity and discontinuity within the history of logical empiricism. Similar research is particularly illuminating when we consider Schlick’s intellectual adventure “before Vienna”3, namely the long period ending with the publication of the first edition (1918) of the General Theory of Knowledge 4. The terminus a quo of Schlick’s early theoretical philosophy may be considered his Habilitationschrift of 1910, which concluded his development of thought from the apprenticeship as a physicist at the school of Max Planck until he began to devote himself to philosophy, in particular to ethical problems5. Now, it is especially our knowledge of Schlick’s philosophical biography in the years from his call to the University of Rostock (1911) to the conclusion of his opus magnum that still seems to lack many details, also as a result of the fact that Schlick published few contributions in this period. Schlick’s philosophical work after the publication both of the Habiltationschrift devoted to The Nature of Truth in Modern Logic and of the nearly contemporaneous study on The Boundaries of Scientific and Philosophical Concept-formation 6 is above all documented in four essays – apart from the unpublished lectures he gave in Rostock, only partially available in English translation7 –, namely the papers on intuitive knowledge, on the philosophical significance of the principle of relativity, on the ideality of space and, finally, on the epistemological consequences of the general theory of relativity for the concepts of space and time8. To be sure, these studies are of 63 F. Stadler (ed.), The Vienna Circle and Logical Empiricism: Re-evaluation and Future Perspectives, 63–77. © 2003 Kluwer Academic Publishers. Printed in the Netherlands.

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greatest importance for an understanding of Schlick’s early epistemology as well as of the background of the General Theory of Knowledge. Nevertheless, they are not the only available ones giving an account of Schlick’s philosophical framework during these years. From 1911 to 1916 Schlick wrote a number of critical reviews which appeared in the “Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie”: more precisely, some 30 reviews, which, to the best of my knowledge, have not been cited in any bibliography of Schlick, although they deserve careful analysis. Indeed, Schlick’s activity as contributor to an influential German philosophical journal offers not only an exhaustive survey of his philosophical and scientific opinions, but also the opportunity to trace Schlick’s intellectual development within both the historical context and the philosophical debates of his time. Schlick had a good relationship with the review founded in 1877 by Richard Avenarius and later edited by Paul Barth with the collaboration of the neoKantian Alois Riehl. Schlick’s papers of 1910 as well as the essays of 1913 and 1916 quoted above appeared in this tribune of “scientific philosophy”, which sought at a kind of harmonization of positivism and neo-Kantianism.9 Moreover, as we can see from some of the letters Riehl addressed to Schlick, Schlick had been well acquainted with Riehl since 1910 and had an opportunity to visit him in Berlin before he moved to Rostock10. Riehl was, on the other hand, one of the thinkers Schlick had studied more intensely in the years of his training, especially as regards Riehl’s fundamental work Der philosophische Kritizismus, the main outcome of which was a realistic interpretation of the Kantian theory of knowledge which certainly influenced Schlick’s conception of critical philosophy11. No wonder, then, that at the very beginnig of his academic career Schlick contributed to the philosophical journal edited by Riehl and published a series of reviews in the “Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie”. Schlick’s attitude as reviewer is based on the conviction that the most important aspect is “to reach an understanding about matters of principle despite all the different points of view”.12 However, this doesn’t imply that Schlick’s reviews lose their strength or do not take a critical position. The examination of authors such as Natorp, Enriques, James, Frischeisen-Köhler, Dingler, Driesch or Cornelius, in particular, makes it clear that Schlick grounded his examination of the main issues of epistemology in his own philosophical achievements and, to some extent, on the point of view he later endorsed in the General Theory of Knowledge. Apart from some reviews which today have only bibliographical significance13, documenting, for example, Schlick’s interest in the history of ancient philosophy14, it seems useful to divide this unknown aspect of his philosophical activity into thematic areas. Schlick reviews a number of books and contributions dealing for the most part with problems of psychology, logic, epistemology and philosophy of science; but from the philosophical point of view he pays special attention, on the one hand, to both the problem of realism and the critique of the so-called empirio-criticism15, and, on the other, to the

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critical interpretation of Kant’s philosophy within the more general framework of an enduring discussion of Neokantianism. From these quite different reviews Schlick emerges as a typical supporter of the “scientific philosophy” in the German culture at the beginning of the century; and so it is very well understandable why Schlick became a regular contributor of the philosophical journal founded by Avenarius, playing a role of some importance in the contemporary debates about both epistemological questions and puzzles posed by the developments of science to the scientific worldview.16 But it is also worth noting that Schlick discussed authors and epistemologic-philosophical problems which are at the core, in the period from 1907 to 1917, of the activity of the so-called “first Vienna Circle”, as is easy to see from the many reviews of Mach, Dingier, Duhem, Enriques, Zilsel, Rey, Planck, Stallo and Poincaré written by Philipp Frank and Hans Hahn17. Schlick, for example, introduced the readers of the “Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie” to the work of Paul Volkman (Erkenntnistheoretische Grundzüge der Naturwissenschaften) and, later, to Hugo Dingler’s Grundzüge der Naturphilosophie, although he criticized both the inadequacy of the way Volkman dealt with physical problems and Dingler’s unrigorous argumentation18. Even more important, though, is Schlick’s review of Federigo Enriques’ main work, which was published in German in 1910 as Problems der Wissenschaft. To be sure, Schlick admired the encyclopedic outlook of contemporary sciences offered by Enriques in his valuable book; nevertheless, he raised a fundamental objection to the relativism endorsed by Enriques on the basis of his positivistic point of view, namely against the idea according to which nothing absolute exists, it being impossible to put an end to any infinite series of relative elements or degrees. But Schlick argued that this argument has no validity, for the good reason that it contradicts the “spirit of critical philosophy” by concluding from the failure of a definition the “nonexistence of the object to define”19. Schlick thus rejected the “fundamental point” of Enriques’ theory of knowledge and he praised, on the contrary, the other parts of his work (for today’s reader, indeed, the most questionable), which offer a survey of logic, methodology and scientific development up to the present20. Let us now turn our attention, first of all, to Schlick’s discussions of psychological books. It should be noted here that Schlick seemed interested in the classical topics of contemporary psychology, for example in the theory of feelings and reflexes21; but he was altogether attracted by the recent results of Gestaltpsychologie, and in his opinion the concepts of quality and form allow “a broader potential for application than is usually assumed”22. On the other hand, Schlick engaged himself in the defence of the scientific character of psychology against the unjustified demands of traditional philosophy23. This tension between philosophy and psychology is the main topic dealt with in the review of William James’s Psychologie, that is of the German, abridged edition of his main work. Schlick considers it an excellent “handbook”, having great merits particularly in its argument on the basis of real experience in everyday life, although this by no

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means is intended “to damage the scientific nature of the book”. Nevertheless, Schlick adds a critical and meaningful remark: “The philosopher James”, he says, “fades quite into the background; and this is to the best advantage of the work” 24 . Here, it is not difficult to recognize Schlick’s polemical assessment of James’s philosophy which he had already expressed in his Habilitationsschrift where he completely rejected James’s “unacceptable” concept of truth inasmuch it is essentially characterized by its “mutability” 25 . This objection represents, of course, the last consequence of Schlick’s general critique of pragmatism, the “unscientific view” of which to him seemed destined to collapse because of its untenable concept of truth, according to which the truth of a proposition depends upon its consequences. And a similar conception of truth is indeed diametrically opposed, in spite of the principle of verification Schlick himself endorsed, to Schlick’s definition of truth as univocal coordination of judgements with states of affairs26. The other side of Schlick’s reviews concerning contributions to psychology can be summarized as an attempt to call attention to the “boundary questions” of logic, psychology and theory of knowledge. This is, for example, the case of Joseph Klemes Kreibig’s book devoted to the study of intellectual functions, which Schlick evaluates as a typical result of the Austrian way of philosophical thinking promoted by authors such as Bolzano, Meinong, Höfler and so on27. Schlick’s arguments in this context are the same ones he developed in 1910 in his paper on the nature of truth as regards the relationship between logic and psychology. It is well known that Schlick discussed here Edmund Husserl’s Logical Investigations and questioned his refusal of psychologism, arguing that it is right for logic to abstract from the individual-psychical aspect, but it is misleading to ignore the psychological element as such. “We cannot […] regard the logical propositions,” he says, “as structures devoid of any mental character” 28. In order to contrast Husserl’s theory of “pure logic” as well as Bertrand Russell’s “platonism”, Schlick refers to the concept of the “organisation of our minds (Organisation des Geistes)”, that is, by the way, to a concept which had been elaborated, most notably, by Friedrich Albert Lange in his History of Materialism29. In Schlick’s opinion, the necessity of truth by no means implies that it can subsist independently from our psychological “organisation” or as something “external of the mind”. “Our truths – this is Schlick’s claim – are dependent upon the organisation of our minds, though it is precisely for that reason that they are necessary for us” 30. Starting from this background, Schlick reviewed, for example, Adolf Stöhr’s Lehrbuch der Logik in psychologisierender Darstellung and others contributions to logical inquiry such as Johannes von Kries’s Logik31 considering, more generally, “the great problem of the relationship between logic and reality” 32 . Two main points seem to emerge here. On the one hand, it is a comprehensive “image” of logic which can be derived from Schlick’s critical notices. So it is remarkable that Schlick, on the occasion of the publication of Ernst Schröder’s Abriss der Algebra der Logik, expressed some doubts regarding its importance

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for the great “revolution” within 20th century logic. Schlick, by contrast, did not believe that the idea of a logical calculus was a very fruitful one, although already the great Leibniz – the hero of modern symbolic logic – placed all his hopes in the calculemus! offering a solution to every philosophical problem. The reason for Schlick’s skepticism was his conviction that a similar optimistic point of view presupposes the entire set of the fundamental concepts representing the reality and the relations underlying the reality itself. “Yet the solution of such a problem – Schlick comments – probably presupposes the solution of all the greatest problems and the algebra of logic would come too late. In the field of mathematics, the algorithmic language of signs is possible and successful because here the basic concepts and the axioms are very few in number. It follows that up to now the algebra of logic has found extensive application in only one field, namely in the field of mathematics itself, which does not require its aid despite the assurances of some spokesmen of logistics (Logistik)” 33 . Schlick’s polemical attitude towards the “logistics” doubtless represents the premise of the more general critique of modern logic he formulated later in the General Theory of Knowledge, in which he stressed, in fact, the still enduring validity of Aristotele’s syllogistic34. To be sure, it is astonishing that in the age of Frege, Peano, Russell and Couturat one of the most influential figures of the future Vienna Circle held a similar idea. And yet the philosophical framework of Schlick’s logical conception must still be clarified. This is exactly the second point emerging from Schlick’s reviews in the period before the publication of his main work. It is thus necessary in this context to recall some others aspects of Schlick’s early thought, especially as regards his theory of knowledge revealing the great influence – or, to some extent, the complex mixture – both of Poincaré’s philosophy of science and of the heritage of Kant’s critical philosophy. Two elements here seem to be meaningful. First of all, Schlick maintained that the philosophy of logic cannot give up the “fundamental difference” between analytic and synthetic judgements as well as between ideal truths and factual truths35. According to Schlick, a similar difference, that is, the difference posed by Leibniz and Hume between vérités de raison (or relations of ideas) and vérités de fait (or matters of fact), is indispensable for constructing logic – in the spirit of Johannes von Kries’s book – as the critical and formal doctrine of judgements36. This point of view, also stressed in the General Theory of Knowledge 37, of course is related to the studies on the criterion of truth Schlick had already pursued in his Habilitationsschrift. Here the distinction between vérités de raison and vérités de fait seeks to prove that, in spite of every difference of principle, both the fields of truth require, at any rate, a procedure of verification consisting in the establishment of “identity (Gleichheit) of judgements” 38. In order to fully understand Schlick’s thesis we have to add another piece to this puzzle. In his reviews as well as in the Habilitationsschrift, Schlick acknowledged again and again Poincarés’s great merits and raised no doubts as to the latter’s scientific genius and the importance of his epistemological work39. According to Schlick, Poincaré definitively demonstrated, on the basis of a

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general Kantian point of view, that “the present-day philosophy of mathematics has abandoned radical empiricism”40. Moreover, Schlick pointed out that Poincaré’s “nominalism” (as Enriques defined it)41 played a leading role within the debates on the relationship between logic and mathematics; in particular, his objections against the logistics and the reduction of mathematics to an “enormous tautology” lie at the core of contemporary disputes on the nature of mathematics, casting a new light upon the classical problems of epistemology since Kant.42 How are all these different remarks Schlick makes in his short contributions to the “Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie” to be understood? Once again, the answer may be found in his Habilitationsschrift, where both themes, namely the distinction between ideal truths and factual truth as well as the philosophy of science endorsed by Poincaré constitute the centre of gravity of Schlick’s early philosophical views. In fact Schlick is convinced that “all judgements having a purely logical or mathematical dignity” are absolutely true and universally valid, whereas this is not the case with empirical judgements or factual truths. But the question is precisely if, and, if so, in what sense, the apriori status of the first kind of judgements and the absolute validity of the first kind of truths enable any a verification of this sort of proposition. Now, according to Schlick, the solution of this problem can be found by conceiving the verification as a procedure that occurs in our inner experience, thus enabling mental experiments or, as in the case of geometry, resorting to intuitive representations. Surprisingly enough, Schlick concluded from these assumptions that inner experience constitutes the ground for every verification of apriori, logical or mathematical judgements and that, therefore, their apodictic character rest upon the “organization of our own understanding”. “So – Schlick says – whereas in empirical truths our conviction of their correctness is based upon the experiences in which we find them confirmed, in a priori propositions it rests upon the structure of our own mind, which makes possible inner experience and finds its expression therein”. Thus Schlick noted in this context that he fit in “in the field of Kant’s philosophy”, and in this sense the laws of the mind are nothing but what Kant called forms both of understanding and sensibility43. It also becomes clear why Schlick, for the first time in his philosophical writings, referred to Poincaré’s authority. Schlick by no means shared Poincaré’s separation of mathematics from logic, insofar as both are subjected to verification through inner experience or induction; and yet Schlick is “wholly at one” with Poincaré regarding the nature of complete induction as “raisonnement mathématique par excellence”. This kind of reasoning is valid in the field of logic as well as in the field of apriori judgements in general, and taken as a whole it makes it clear the “subjective or a priori origin” of “eternal truth” 44 . Schlick’s epistemological interest in this connection can also be defined as an attempt to use Poincaré for support in finding the criterion of truth in the spirit of Kant’s philosophy (in a broad sense). Poincaré’s conventionalism and his philosophy of geometry, on the contrary, have a very marginal role in this context, unlike what characterized

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Schlick’s later reception of these topics in the framework of his epistemological analysis of Einstein’s theory of relativity. It is not possible here to offer an extensive account of Schlick’s gradual revision of his former commitment to “the field of Kant’s philosophy” and to illustrate his new, surely more anti-Kantian perspective in the General Theory of Knowledge. At any rate, the fact that Schlick moved away from Kantianism and neo-Kantianism is more complicated than is usually maintained, and is well documented by some reviews he published during these years. Schlick, for example, pointed out in his 1916 discussion of Hans Cornelius’s Transzendentale Systematik, that this “excellent publication” has doubtless the merit of aspiring to a “new orientation” of the transcendental method, in particular as a result of the new laws of consciousness Cornelius was able to show (e.g. recognizing, remembering, distinguishing and so on)45. But much more interesting is perhaps Schlick’s agreement with Cornelius on the necessary transformation of the Kantian thing in itself, namely for the good reason, as Schlick says, that “the transcendent, uncognizable thing in itself has to be substituted by the empirical cognizable thing in itself” 46. As is well known, the theory of things in itself as cognizable things is precisely the main point of the General Theory of Knowledge47 ; and yet it is instructive to see how Schlick gradually elaborates this argument during the period of his activity as a reviewer, combining, so to speak, Riehl’s suggestions for a realistic interpretation of Kant with other contemporary sources and philosophical arguments. This is clearly the case of Max Frischeisen-Köhler’s book Wissenschaft und Wirklichkeit, which Schlick reviewed in 1913, agreeing with the proofs in favour of the realism exhibited by this pupil of Wilhelm Dilthey. Schlick had been, of course, deeply interested in this topic since his training with Planck, whose physical realism he for the most part accepted48. Now Schlick found in Frischeisen-Köhler’s book, as well as in some arguments already proposed by Dilthey, the stimulating idea that the proof of the reality of the external world as independent from us does not follow from any theoretical reason, but is only the outcome of the practical, immediate experience (Erlebnis) of something resisting us (Hemmung)49. On the other hand, Schlick suggested that Frischeisen-Köhler’s objections against the neo-Kantian idealism both of the Baden and the Marburg Schools are “absolutely very well selected and perfectly right”50. To be sure, concerning Windelband and especially Rickert, this opinion does not represent any new, considering that Schlick had already expressed it in his Habilitationsschrift, where, once again starting from an essay by Frischeisen-Köhler, he developed a stringent critique of Rickert’s conception of truth as “a total reversal” of the customary and established relationship between judgements and reality51. But in the case of the Marburg school, Schlick was very happy to see that Frischeisen-Köhler criticized, on the basis of “successful” arguments, the conception of the object of knowledge as an “infinite task”, as the X of knowledge determined absolutely through the pure thought. On the contrary, Schlick

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says by quoting Frischeisen-Köhler himself that “the object must have a determination already before the act of knowing” 52 . The polemical attitude towards the logical idealism of the Marburg school also figures centrally in an extensive review Schlick wrote in 1911 on Paul Natorp’s famous book Die logischen Grundlagen der exakten Wissenschaften: a review inaugurating, moreover, Schlick’s engagement as contributor to the “Vierteljahrschrift” 53 . To understand the more general point of view underlying this very meaningful discussion of Natorp’s main epistemological work, it is useful to quote first of all the last passages of Schlick’s review, which include an ironical laudatio of the Marburg neo-Kantianism: “To be sure, even the rival of this logical idealism will find in every chapter of this book, which is indeed very difficult for the reader, a lot of stimulating themes, and it is a pleasure to follow the bold paths covered by the enthusiastic author, although one will, in the end, abandon these lands of “pure thought” with a sigh of relief” 54. Similar skeptical remarks about the role of “pure thought”, and Schlick’s own conception of the object of knowledge as something quite independent from thought, also underlie the critical examination of the Marburg neo-Kantianism in which Schlick engaged still later in his General Theory of Knowledge. And there can be no doubt that for Schlick, in 1911 as well as in 1918, the forms of thought by no means had the status of “creative forms” asserted by Cohen and Natorp; on the contrary, they are purely “ forms of the given”.55 However, what seems noteworthy in the review of Natorp is that Schlick juxtaposed Kant’s pure intuition to the Marburg theory of pure and creative thought as the exclusive ground of knowledge. Whereas Natorp attempted to provide the logical foundation of mathematics by transforming Kant’s transcendental logic, Schlick, by contrast, emphazised that Kant’s critical project depends upon the distiction between transcendental aesthetics and transcendental logic56. According to Schlick, this means that Natorp’s “unfortunate conception” about space and time as mere products of pure thought had to be abandoned. Schlick, in fact, “protested” expressly against the (in his opinion) “Hegelian” misinterpretation of Kant proposed by Natorp. Instead he drew the attention to the circumstance that assuming space and time as mere conceptual orders implies the ignorance of their differentia specifica, that is, the difference based upon pure intuition and distinguishing space and time as mathematical concepts57. Schlick thus informed the readers of the “Vierteljahrschrift” of Natorp’s failure to determine the content of thought by resort to intuition; and he added that “in the reviewer’s opinion, the other chapters of the book also fail to acknowledge the role intuition has played by achieving some results” 58. To be sure, Schlick certainly did not aim at being a kind of “orthodox” Kantian 59 , as he says elsewhere. But, at least at this time, Schlick was convinced that it was still possible to defend Kant’s philosophy of geometry based upon intuition. In 1911, for example, he remarked that the geometrical axioms are characterized by intuitive necessity, but not by conceptual necessity; from this it follows, according to Schlick, that it is possible to reconcile Kant with non-

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Euclidean geometries insofar as geometries belong only to the field of possibilities of thought60. Here Schlick seemed to be acquainted with the “strategies of immunization” put forward by most neo-Kantians and, more precisely, with Riehl’s influential solution to the puzzle about Kant and non-Euclidean geometries61. But this point of view was to be completely given up in the General Theory of Knowledge, in which Schlick no longer considered geometrical space as intuitive representation and, in spite of his former neo-Kantian way out, he defined the space in terms of pure conceptual idealisation62. This collapse of spatial intuition in a Kantian or neo-Kantian sense is surely connected, on the one hand, to Schlick’s more general refusal of intuition within the process of knowledge and philosophical inquiry (as was endorsed, by contrast, by Husserl, Bergson and other thinkers)63, and, on the other hand, to Schlick’s epistemological analysis of Einstein’s theory of relativity since 1915. The last aspect already can be traced back to the review of Natorp64 but emerges most prominently in the discussion about both Natorp’s and Richard Honigswald’s attempts to provide a neo-Kantian foundation to the principle of relativity, according to which pure space and pure time may still play the role of transcendental presuppositions of every empirical measurement of fully relativized spaces and times: i.e., exactly the solution Schlick believed to be incompatible with modern relativistic physics65. And yet in 1915 Schlick was still convinced that Kant’s theory of knowledge and, in particular, his doctrine of space and time had not to be abandoned, but only modified with regard to “essential parts”.66 For Schlick, in any case, a similar modification did not damage the correct point of view endorsed both by Kantian philosophy and neo-Kantianism, that is, the conception of philosophical analysis as “critical inquiry into the ultimate principles of the special sciences”, which together makes possible the epistemological justification of all the “newly discovered principles” emerging from their historical development67. This attitude also characterized Schlick’s reviews during the period from 1911 to 191668 and constituted, more generally, the background of his philosophical activity up to the General Theory of Knowledge. At the end of this long path much of which involved his contributions to the “Vierteljahrschrift fur wissenschaftliche Philosophie und Soziologie”, Schlick was on the threshold to a new development of his thought, which is surely best known and studied largely by the scholars of Schlick’s philosophy. But the period beginning with both the epistemological analysis of relativistic physics and the General Theory of Knowledge of 1918 belongs to another stage of Schlick’s intellectual biography. And this story, we hope, will be told elsewhere.

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APPENDIX: SCHLICK’S REVIEWS FOR THE “VIERTELJAHRSCHRIFT FÜR WISSENSCHAFTLICHE PHILOSOPHIE UND SOZIOLOGIE” P. Natorp, Die logischen Grundlagen der exakten Wissenschaften (Berlin/Leipzig: Teubner 1910), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 35, 1911, pp.254-260 (Schlick 1911a). A. Voß, Über das Wesen der Mathematik (Leipzig/Berlin: Teubner 1908), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 35, 1911, pp. 260-261 (Schlick 1911b). L. Goldschmidt, Zur Wiedererweckung Kantscher Lehre (Gotha: F.A. Peters 1910), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 35, 1911, pp. 261-262 (Schlick 1911c). A. Bilharz, Descartes, Hume und Kant. Eine kritische Studie zur Geschichte der Philosophie (Wiesbaden [unknown publishers] : 1910), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 35, 1911, pp. 262-263 (Schlick 191 1d). G. Mannoury, Methodologisches und Philosophisches zur Elementarmathematik (Harlem [unknown publishers]: 1909), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 35, 1911, pp. 263-265 (Schlick 1911 e). E. Schröder, Abriss der Algebra der Logik (bearbeitet im Auftrag der Deutschen Mathematiker-Vereinigung von E. Müller, I. Teil, Leipzig: Teubner 1910), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 35, 1911, pp.265-266 (Schlick 1911f). F. Enriques, Probleme der Wissenschaft (German transl. by K. Grelling, 2 volls., Leipzig/Berlin: Teubner 1910), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 35, 1911, pp. 266-269 (Schlick 1911g). A. Stöhr, Lehrbuch der Logik in psychologisierender Darstellung (Leipzig/Vienna: Fr. Deuticke [without year]), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 35, 1911, pp. 269-270 (Schlick 1911h). A. E. Haas, Die Entwicklungsgeschichte des Satzes von der Erhaltung der Kraft (Vienna: Hölder 1909), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 35, 1911, pp. 270-271 (Schlick 1911i). R. Eisler, Grundlagen der Philosophie des Geisteslebens (Leipzig: W. Klinkhardt 1908), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 35, 1911, pp. 271 -272 (Schlick 1911l). W. Wundt, Die Prinzipien der mechanischen Naturlehre (Stuttgart: Enke 1910), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 35, 1911, pp. 439-441 (Schlick 1911m). O. Boelitz, Die Lehre vom Zufall bei Emile Boutroux. Ein Beitrag zur Geschichte der neuesten französischen Philosophie (Leipzig: Quelle & Meyer 1907), in: Vierteljahrschrif für wissenschaftliche Philosophie und Soziologie, 35, 1911, p. 441 (Schlick 1911n).

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J. Petersen, Kausalität, Determinismus und Fatalismus (Munich: J.F. Lehmanns Verlag 1909), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 35, 1911, pp. 442-443 (Schlick 1911o). C. Stumpf, Philosophische Reden und Vorträge (Leipzig: Barth 1910); Die Wiedergeburt der Philosophie (Leipzig: Barth 1908); Vom ethischen Skeptizismus (Leipzig: Barth 1909), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 35, 1911, pp.443-444 (Schlick 1911p). P. Volkmann, Erkenntnistheoretische Grundzüge der Naturwissenschaften und ihre Beziehungen zum Geistesleben der Gegenwart (Leipzig/Berlin: Teubner 1910), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 36, 1912, pp. 293-294 (Schlick 1912a). P. Volkmann, Die Eigenart der Natur und der Eigensinn des Monismus. Vortrag (Leipzig/Berlin: Teubner 1910), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 36, 1912, pp. 294-295 (Schlick 1912b). W. James, Psychologie (german transl. by M.Dürr, Leipzig: Quelle & Meyer 1909), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 36, 1912, p. 295 (Schlick 1912c). J. K. Kreibig, Die intellektuellen Funktionen. Untersuchungen über die Grenzfragen der Logik, Psychologie und Erkenntnistheorie (Vienna/Leipzig: Hölder 1909), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 36, 1912, pp. 296-297 (Schlick 1912d). M. Rubner, Kraft und Staff im Haushalte der Natur (Leipzig: Akademische Verlagsgesellschaft 1909), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 37, 1913, pp. 142-143 (Schlick 1913a). K. C. Schneider, Vorlesungen über Tierpsychologie (Leipzig: Engelmann 1909), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 37, 1913, pp. 143-145 (Schlick 1913b). M. Frischeisen-Köhler, Wissenschaft und Wirklichkeit (Leipzig / Berlin: Teubner 1912), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 37, 1913, pp. 145-148 (Schlick 1913c), S. Lourié, Die Prinzipien der Wahrscheinlichkeitsrechnung. Eine logische Untersuchung des disjuntiven Urteils (Tübingen: Mohr 1910), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 38, 1914, pp. 276-277 (Schlick 1914a). H. Lüdemann, Das Erkennen und die Werturteile (Leipzig: M. Heinsius Verlag 1910), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 38, 1914, pp. 277-278 (Schlick 1914b). H. Dingier, Die Grundlagen der Naturphilosophie (Leipzig: Verlag Unesma 1913), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 39, 1915, pp. 374-376 (Schlick 1915a). E. Becher, Weltgebäude, Weltgesetzte, Weltentwicklung (Berlin: Reimer 1915), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 40, 1916, pp. 255-257 (Schlick 1916a). H. Driesch, Die Logik als Aufgabe. Eine Studie über die Beziehung zwischen Phänomenologie und Logik, zugleich eine Einleitung in die Ordnungslehre

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(Tübingen: Mohr 1913), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 40, 1916, pp. 257-259 (Schlick 1916b). F. Raab, Die Philosophie von Richard Avenarius. Systematische Darstellung und immanente Kritik (Leipzig: Meiner 1912), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 40, 1916, pp. 259-260 (Schlick 1916c). A. Lehmann, Die Hauptgesetzte des menschlichen Gefühlslebens (Leipzig: Reisland 1914), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 40, 1916, pp. 372-374 (Schlick 1916d). W. von Bechterew, Objektive Psychologie oder Psychoreflexologie, Die Lehre von den Assoziationsreflexen (Leipzig/Berlin: Teubner 1913), in: Vierteljahrschriftfür wissenschaftliche Philosophie und Soziologie, 40, 1916, pp. 374-376 (Schlick 1916e). J. Burnet, Die Anfänge der griechischen Philosophie (german transl. Leipzig/Berlin: Teubner 1913), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 40, 1916, pp. 376-377 (Schlick 1916f). R. Herbetz, Prolegomena zu einer realistischen Logik (Halle: Niemeyer 1916), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 40, 1916, pp. 377-380 (Schlick 1916g). J. von Kries, Logik. Grundzüge einer kritischen und formalen Urteilslehre (Tübingen: Mohr 1916), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 40, 1916, pp. 380-384 (Schlick 1916h). H. Cornelius, Transzendentale Systematik. Untersuchungen zur Begründung der Erkenntnistheorie (Munich: Reinhardt 1916), in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 40, 1916, pp. 384-386 (Schlick 1916i).

NOTES

1.

2.

Cf. the contributions of Herbert Feigl, “Moritz Schlick”, in: Erkenntnis, 7, 1937/38, pp. 393419, transl. in: Henk L.Mulder/Barbara F.B.van de Velde-Schlick (Eds.), Moritz Schlick: Philosophical Papers, Vol. I (1909-1922), Dordrecht: Reidel 1979, pp.XV-XXXVIII; Friedrich Waismann, “Vorwort”, in: Moritz Schlick, Gesammelle Aufsätze 1926-1936, Vienna: Gerold & Co. 1938 (reprint Hildesheim: Olms 1969), pp.VII-XXXI; Eugene T.Gadol (Ed.), Rationality and Science. A Memorial Volume for Moritz Schlick in Celebration of the Centennial of His Birth, Vienna-New York: Springer 1982; Anthony Quinton, “Vor Wittgenstein: der frühe Schlick”, in: Brian McGuinness (Ed.), Zurück zu Schlick. Eine Neubewertung von Werk und Wirkung, Vienna: Hölder-Pichler-Tempsky 1985, pp. 114-133. A short biography of Schlick together with an extensive bibliography of his writings as well as of his courses at the University of Vienna is offered by Friedrich Stadler, The Vienna Circle. Studies in the Origins, Development, and Influence of Logical Empiricism, Vienna-New York: Springer 2001, pp. 722-730 (see also pp. 869-909 for an impressive collection of documents concerning the murder of Schlick). Finally, I allow myself to refer the reader to my forthcoming essay “Der junge Schlick. Ein Stück intellektueller Biographie“ (lecture delivered in Vienna and Graz, March 2000). Cf. for example Karin Gerner, Hans Reichenbach. Sein Leben und Wirken, eine wissenschaftliche Biographie, Osnabrück: Phoebe-Autorenpress 1997. See also the critical review of this book by Reinhard Siegmund-Schultze in: Miklós Rédei/Michael Stölzner (Eds.), John von

AN UNKNOWN SIDE OF MORITZ SCHLICK’S INTELLECTUAL BIOGRAPHY

3. 4.

5.

6.

7. 8.

9.

10. 11.

12.

13. 14. 15. 16. 17. 18.

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Neumann and the Foundations of Quantum Physics, Dordrecht/Boston/London: Kluwer 2001, pp. 337-340. Alberto Coffa, The Semantic Tradition from Kant to Carnap. At the Vienna Station, Cambridge: Cambridge University Press 1991, pp. 171-188. Moritz Schlick, Allegemeine Erkenntnislehre, Berlin: Springer, 1918 revised ed. 1925 (reprint Frankfurt/Main: Suhrkamp 1979), English transl. General Theory of Knowledge, with an introduction by Albert E.Blumberg and Herbert Feigl, Vienna-New York: Springer-Verlag 1974. Moritz Schlick, Über die Reflexion des Lichtes in einer inhomogenen Schicht, Berlin: Inaugural Dissertation 1904; Lebensweisheit. Versuch einer Gliickseligkeitslehre, Munich: Beck 1908; “Das Wesen der Wahrheit nach der modernen Logik”, in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 34, 1910, pp. 386-477, reprint in: Moritz Schlick, Philosophische Logik, ed. by Bernard Philippi, Frankfurt/Main: Surhkamp 1986, pp. 31-109 (English transl. “The Nature of Truth in Modern Logic”, in: Schlick, Philosophical Papers Vol. I, op. cit., pp.41-103). A brief survey of the young Schlick’s early philosophical attempts may be found in Massimo Ferrari, “Der junge Schlick. Ein Stück intellektueller Biographic”, pp. 2-18. Moritz Schlick, “Die Grenze der naturwissenschaftlichen und philosophischen Begriffsbildung”, in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 34, 1910, pp. 121-142, reprint in: Schlick, Philosophische Logik, op. cit., pp. 11-30 (English transl. “The Boundaries of Scientific and Philosophical Concept-formation”, in: Schlick, Philosophical Papers Vol. I, op. cit., pp. 25-40). Cf. Schlick, Philosophical Papers Vol. I, op. cit., pp. 104-140. Cf. Moritz Schlick, “Gibt es intuitive Erkenntnis?”, in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 37, 1913, pp.472-488, English transl. “Is There Intuitive Knowledge?”, in: Schlick, Philosophical Papers Vol. 1, op. cit., pp. 141-152; “Die philosophische Bedeutung des Relativitätsprinzips”, in: Zeitschrift für Philosophie und philosophische Kritik, 159. 1915, pp. 129-175, English transl. “The Philosophical Significance of the Principle of Relativity”, in: Schlick, Philosophical Papers Vol. 1, op. cit., pp. 153-189; “Idealität des Raumes, Introjektion und psychophysisches Problem”, in: Vierteljahrschrift für wissenschaftliche Philosophie und Soziologie, 40, 1916, pp. 230-254, English transl. “Ideality of Space, Introjection and the Psycho-Physical Problem”, in: Schlick, Philosophical Papers Vol. I, op. cit., pp. 153-189; “Raum und Zeit in der gegenwärtigen Physik”, in: Die Naturwissenschaften, 5, 1917, pp. 161167, 177-186, English trans, of the enlarged edition (Berlin: Springer 1922) “Space and Time in Contemporary Physics”, in: Schlick, Philosophical Papers Vol. I, op. cit., pp. 207-269. See Klaus Christian Köhnke, Entstehung und Aufstieg des Neukantianismus. Die deutsche Universitätsphilosophie zwischen Idealismus und Positivismus, Frankfurt/Main: Suhrkamp 1986, pp. 388-404. We refer to Schlick’s Nachlaß , Inv. Nr. 114. See once again Schlick’s Nachlaß, Inv. Nr. 163 “128” (it is about Schlick’s notes from vol. II of Riehl’s book). For a survey of Riehl’s neo-Kantianism cf. Wolfgang Röd, “Alois Riehl und der Herbartianismus in Österreich”, in: J.C. Nyiri (Ed.), Von Bolzano zu Wittgenstein. Zur Tradition der österreichischen Philosophie, Vienna: Hölder-Pichler-Tempsky 1986, pp. 132-140; Massimo Ferrari, Introduzione a II neocrilicismo, Rome-Bari: Laterza 1997, pp.36-40, 90-92; Manfred Pascher, Einführung in den Neukantianismus, Munich: Fink 1997, pp. 67-69; Renato Pettoello, “De Herbart à Kant. Quelques considérations sur le réalisme de Alois Riehl”, in: Revue de Mêtaphysique et de Morale, 102, 1998, pp. 347-366. See Schlick 1916c, p. 260. We quote Schlick’s reviews only giving the year of publication and following, within the same year, an order indicated by alphabetic letters. The complete list of the reviews can be found in the appendix to this paper. See Schlick 1911d, 1911i, 1911l, 1911n, 1911o, 1911p, 1912b, 1913a, 1914b. Schlick 1916f. Schlick 1916c, p. 260. See e.g. Schlick 1916a. Cf. Thomas Uebel, Vernunftkritik und Wissenschaft. Otto Neurath und der erste Wiener Kreis, Vienna-New York: Springer 2000, p. 182. Schlick 1912 and Schlick 1915.

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19. 20. 21. 22.

23. 24. 25. 26. 27. 28. 29.

30.

31. 32. 33. 34.

35. 36. 37. 38. 39.

40. 41. 42. 43. 44. 45. 46. 47. 48.

49. 50. 51.

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Schlick 1911g, p. 268. Ibid, pp. 268-269. See Schlick 1916d and Schlick 1916e. Schlick 1912d, p. 297; see also Schlick 1916b, p. 258, Schlick examines Gestaltpsychologie still later, during a seminar at the University of Vienna in the years 1933-1934 (cf. “Gestaltpsychologie”, ed. by F.Stadler, in: Conceptus, 21, 1987, 53-54, pp. 127-142). Also see Schlick, General Theory of Knowledge, op. cit., pp. 68-69, concerning especially a brief discussion of Ehrenfels. Schlick 1913b, p. 145. Schlick 1912c, p.295 Schlick, “The Nature of Truth in Modern Logic”, loc. cit., pp. 64-65. Ibid., pp. 64-68, 88,94 ff. Schlick 1912d, p.296. Schlick, “The Nature of Truth in Modern Logic”, loc. cit., p. 54. Schlick expresses his esteem for Lange’s masterpiece elsewhere too: see “The Boundaries of Scientific and Philosophical Concept-formation”, loc. cit., p. 30 and General Theory of Knowledge, op. cit., p. 327. Schlick, “The Nature of Truth in Modern Logic”, loc. cit., p.98. Cf. also pp. 55-56, where Schlick considers “perfectly correct” Herbert Spencer’s psychological interpretation of the principle of contradiction (a point sharply contradicted by Husserl’s critique of psychologism). Schlick 1911h and Schlick 1916h. Schlick 1916g, p. 377. Schlick 1911f, p. 266. Schlick, General Theory of Knowledge, op. cit., p. 107. See also Warren Goldfarb, “The Philosophy of Mathematics in Early Positivism”, in: Ronald N. Giere/Alan W. Richardson (Eds.), Origins of Logical Empiricism, Minneapolis/London: University of Minnesota Press 1996, p.215. Schlick 1916f, p. 378. Schlick 1916h, p. 381. Schlick, General Theory of Knowledge, op. cit., p. 170. Schlick, “The Nature of Truth in Modern Logic”, loc. cit., pp.80, 86-88 (translation slightly modified). Schlick 1912a, p. 294; Schlick 1913, p.486. Schlick’s admiration for Poincaré concerns at the same time his contribution to the theory of probability: “Anybody who looks for clarity about the principles of the calculus of probability has to consult the books of a mathematician such as Poincaré. One will find therein, although condensed in few propositions, more correct insights into the essence of probability than are offered by the long and to some extent metaphoric arguments of Lourié” [Schlick was referring here to Samuel Lourié’s Prinzipien der Wahrscheinlichkeitsrechung, i.e. the book which he is just reviewing] (Schlick 1914a, p. 277). Schlick 191 le, p. 265. Schlick 191 lg, p. 268. Schlick 191 lb, p. 260. Schlick, “The Nature of Truth in Modern Logic”, loc. cit., p. 84 (translation slightly modified). Ibid.,p. 85. Schlick 1916i, p.385. Schlick 1916i, p. 386. Schlick, General Theory of Knowledge, op. cit., pp. 88ff., 194ff., 235ff. Cf. Joia Lewis Turner, “Conceptual Knowledge and Intuitive Experience: Schlick’s Dilemma”, in: Ronald N. Giere/Alan W. Richardson (Eds.), Origins of Logical Empiricism, op. cit., pp. 292294; Ferrari, “Der junge Schlick. Ein Stück intellektueller Biographic”, pp. 4-11. Schlick 1913c, p. 146. See General Theory of Knowledge, op. cit., p. 176 and Coffa, The Semantic Tradition, op. cit., p. 406. Schlick 1913c, p. 145. Schlick, “The Nature of Truth in Modern Logic”, loc. cit., pp.45 ff., especially p.49. See also Max Frischeisen-Köhler, “Über die Grenzen der naturwissenschaftlichen Begriffsbildung”, in: Archiv für systematische Philosophie, 12, 1906, pp. 225-266.

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52. 53. 54. 55. 56. 57. 58.

59. 60. 61.

62. 63. 64. 65.

66. 67. 68.

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Schlick 1913c, p. 145. Schlick 1911a. Schlick 1911a, p.260. Schlick General Theory of Knowledge, op. cit., p. 382. See also ibid., p. 366: “In our view, facts stand fixed even without being captured by concepts“. Schlick 1911a, p. 255. Schlick 1911a, p. 257. Schlick 1911a, p.258. Schlick remarks, furthermore, that Natorp’s claim to draw all the determinations of thought from the principle of the pure “origin” (Ursprung) is untenable: “Indeed, the concepts at work here are so abstract, that it seems impossible to employ them without building unvoluntarily intuitive images, and the language must be therefore a metaphoric one in order to describe similar concepts” (Schlick 1911 a, p. 257). Schlick 1911c. Schlick 1911b, p.261. See Alois Riehl, “Helmholtz in seinem Verhältnis zu Kant”, in: Kant-Studien, 9, 1904, pp. 261285 (esp. pp. 276-277) and Alois Riehl, Der philosophische Kritizismus. Geschichte und System, vol. II, Die sinnlichen und logischen Grundlagen der Erkenntnis, (1879), 2nd revised edition, Leipzig: Kröner 1925, pp. 216-221. Schlick General Theory of Knowledge, op. cit., pp. 352-353. See Schlick, “Is There Intuitive Knowledge?”, loc. cit., especially p. 149 for a similar critique of Kant’s pure intuition. Schlick 1911a,p.260. Schlick, “The Philosophical Significance of the Principle of Relativity”, loc. cit., p. 176-178. On the discussion between Schlick and Hönigswald see Massimo Ferrari, “Eine Diskussion über die Relativitätstheorie. Richard Hönigswald und Moritz Schlick”, in: Wolfdietrich SchmiedKowarzik (Ed.), Erkennen-Monas-Sprache. Internationales Richard-Hönigswald-Symposion Kassel 1995, Würzburg: Königshausen & Neumann 1997, pp. 183-194. Schlick, “The Philosophical Significance of the Principle of Relativity”, loc. cit., p. 178. Ibid., pp. 153-154. See for example Schlick 1911m, p. 441.

Dipartimento di Storia University of L’Aquila I-67100 L’Aquila, Via Roma 33 Italy [email protected]

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HANS JUERGEN WENDEL

BETWEEN MEANING AND DEMARCATION

1. A CRITERION OF DEMARCATION DOES NOT DISTINGUISH BETWEEN MEANING AND NONSENSE BUT BETWEEN CONCEPTUALLY DIFFERENT KINDS OF KNOWLEDGE – IN THIS RESPECT, IT IS A CRITERION OF MEANING.

In his Critique of Pure Reason, Immanuel Kant’s main intention was to demarcate justifiable and legitimate cognitive claims within metaphysics in order to place philosophical knowledge on secure foundations. His much-discussed conclusion was that all metaphysical cognitive claims that go beyond subjective conditions of possible knowledge remain unjustifiable. As a result of the breakthroughs in the empirical sciences and the advances in the quest to clarify the foundations of logic and mathematics in the 20th century a need for demarcation arose not only with respect to exaggerated philosophical deliberations but also to all non-science and thus to philosophy as a whole. In the process, possible factual knowledge has been restricted to the domain of scientific knowledge alone. Logical Empiricism employs verifiability as a criterion of meaning primarily to demarcate a meaningful use of language with rich empirical content from empty and therefore meaningless use of language by stating the basis of the validity of experience. In their characterization of scientific statements, the members of the Vienna Circle took a methodological demarcation of scientific method as their starting point, relying on Bacon’s characterization of the natural sciences as inductive sciences. In their view, general statements about nature can only be justified through repeated observations or experiments. This inductive method seemed to be a positive feature of all science. By resorting to this supposed characteristic of empirical science, the members of the Vienna Circle wanted to demarcate it from metaphysics. Simultaneously, however, this demarcation meant to them a demarcation between the meaningful and the meaningless. It should be noted, however, that their position identifies being meaningful with being empirically meaningful, empirical verifiability – that is, inductive provability through observational statements – being regarded as the criterion. This characterization leads not only to insuperable difficulties in the demarcation of what is to be regarded as scientific, but, combined with the view that this exclusively determines the meaning of ‘knowledge’ in general, it also makes its adherents regard all other statements as meaningless or as pseudo-statements. 79 F. Stadler (ed.), The Vienna Circle and Logical Empiricism: Re-evaluation and Future Perspectives, 79–94. © 2003 Kluwer Academic Publishers. Printed in the Netherlands.

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In his critical analysis of the inadequacy of the empirical criterion of meaning, Karl Popper emphasized the importance of an adequate criterion of demarcation: 1. No significant part of science must be excluded; 2. It is problematic to use such a distinction not only to demarcate science from non-science (metaphysics) but also to identify knowledge in general with scientific knowledge. In his Logic of Scientific Discovery 1 Popper therefore proposed falsifiability as the suitable criterion of demarcation that enables us to distinguish between scientific and non-scientific knowledge within the realm of knowledge without imposing a verdict of meaninglessness on the realm of philosophy in the way logical positivists of the Vienna Circle2 had wanted to. ‘Falsifiability’, Popper says, ‘separates two kinds of perfectly meaningful statements: the falsifiable and the non-falsifiable. It draws a line within meaningful language, not around it.’3. From this point of view it looks as if this demarcation is indeed of a conceptual nature and, in addition, factually important because inadequate demarcation concerns everything belonging to empirical science, as the critique of the empiricist criterion of meaning has shown. When Popper says that it is not important to define the concept of science but to give a criterion that factually distinguishes scientific statements in order to delimit them from other statements, he is not opposing the indication of linguistic meaning to the indication of a factual criterion, rather is he opposing definition in the sense of explicit definitory stipulation to analysis in the sense of an explication and clarification of actual linguistic usage. On closer examination, Popper’s critique therefore does not replace a criterion of meaning by a criterion of demarcation, rather it is a critique of an inadequate explication of what constitutes the nature of scientific method and a proposal for a better understanding of the peculiar characteristics of science. Nonetheless, Popper rejects all opinions which assume that one could possibly gain insight into the nature of things by conceptual or ‘Wesensanalysis.’ 4 He considers all such positions to be forms of ‘essentialism’ – in his view an untenable doctrine.5 Such a position assumes that conceptual clarification or definition enables us to make ‘a statement of the inherent essence or nature of a thing’.6 A definition in this sense ‘states the meaning of a word – of the name that designates the essence.’ (ibid.). But to Popper’s mind, questions of conceptual clarification or definition have nothing to do with knowledge. Definitions are never factual. If the meaning of terms depends on conventions7 alone, then all arguments about concepts insofar as they are concerned with cognitive claims turn out to be fruitless because – according to Popper – definitions can never add anything to our factual knowledge about the nature of things,8 since the descriptive content connected with linguistic expressions is of a purely conventional nature. For this reason, the argument about concepts or their definitions is, according to Popper,

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an epistemologically fruitless undertaking. Which is why he says: ‘[...] we should altogether avoid, like the plague, discussing the meaning of words. Discussing the meaning of words is a favourite game of philosophy, past and present: philosophers seem to be addicted to the idea that words and their meaning are important, and are the special concern of philosophy.’9 Instead, ‘one should always keep to assertions, to theories, and the question of their truth. One should never get involved in verbal questions or questions of meaning, and never get interested in words. If challenged by the question of whether a word one uses really means this or perhaps that, then one should say “I don’t know, and I am not interested in meanings; and if you wish, I will gladly accept your terminology.” This never does any harm.’10 What we are really interested in, in Popper’s view, are ’our real problems, are factual problems, or in other words, problems of theories and their truth.’11 Thus, Popper wants to have questions of knowledge strictly separated from questions of linguistic meaning. On the other hand the criterion of demarcation should in any event be factual if it is to be useful. 2. WHETHER WE CONSIDER SOMETHING TO BE KNOWLEDGE OR A MATTER OF CONCEPTUAL CLARIFICATION DEPENDS ON THE CONTEXT OF KNOWLEDGE.

Popper rather casually admits that useful conceptual stipulations in particular have to be factually well-founded when he says that it is not important to overthrow metaphysics but, ‘to formulate a suitable characterization of empirical science, or to define concepts such as “empirical science” and “metaphysics”’ (LD 37). Giving a suitable criterion of demarcation can therefore be regarded as a factually justified ‘proposal for an agreement or convention’ (LD 37). What Popper does not see is the connection between questions of linguistic meaning and questions of knowledge. With his explication of the distinction between analytic and synthetic judgements, Kant wanted to emphasize that especially in philosophy, many of our judgements that allegedly extend our knowledge are basically not ampliative judgements but merely hidden clarifications of given concepts in the disguise of ampliative knowledge, a fact we typically tend to overlook. The mere analysis of concepts would therefore often wrongly be regarded as new knowledge. But the extension of knowledge is very different from the clarification of concepts and, therefore, the two have to be kept apart. Kant’s motive for the introduction of the distinction between analytic and synthetic judgements, that is, between conceptual clarifications and factual judgements, was essentially epistemological. He was aiming at a strict distinction between judgements that can rightfully claim to be extensions of knowledge and those that only clarify given knowledge. In making this distinction of cognitive value between different kinds of judgements Kant was concerned with the cognitive aspect of our route to knowl-

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edge, which is why he distinguished (i) acts of judgement with respect to their cognitive value (for the subject). In Kant’s opinion there exists (ii) a fundamental connection between cognitive judgements and the formation of concepts in such a way that knowledge simultaneously influences concepts so that cognition always implies at the same time formation of concepts; he therefore demanded that the appraisal of the cognitive value of a judgement always be referred to a particular level of knowledge (iii). Taking into account the dynamic aspect of knowledge which leads us to look at the progress of knowledge as a succession of levels of knowledge, the cognitive value of acts of judgements – in Kant’s view – changes accordingly: what was informative at a former level of knowledge (and therefore of the formation of concepts) may now be a mere clarification (iv). According to Kant, the distinction between analytic and synthetic judgements refers to the different ways – differing with regard to their cognitive value – in which subject and predicate can be connected with one another in an act of judgement with respect to their content: If the predicate is already inherent in the subject – in the notion I already havel2 – then our knowledge about (the objects subsumed under) the subject cannot be extended by relating it to this predicate; in the act of judgement we have nothing more than a clarification of the subject in question, an explication of what I already know of it. Whereas if subject and predicate differ with respect to their content inasmuch as the given subject does not already contain the predicate, then both become connected only in the act of judgement so that in the process the subject comes to be extended through additional determination: thus we have a synthesis in the act of judgement. In distinguishing between analytic and synthetic judgements, Kant was therefore mainly concerned with different types of connection as differing cognitive acts and not with the sources of the validity of such connections. For this reason, Kant regards the difference in the possible relation between the content of subject and predicate, that is, the distinction between analytic and synthetic judgements, as fundamental in terms of its cognitive value. 13 The point for Kant was to distinguish judgements that only ‘clarify’ already given knowledge (the concept that one already has of the object to be cognized) from those that give some new insight (that ‘extend’ our concept of the thing), and not to assign them to totally different spheres according to their nature so that the one type has to do with semantics and the other with knowledge. If knowledge – including the process of forming concepts – progresses then newly gained knowledge necessarily becomes given knowledge, which is in turn capable of being further extended and so on. Consequently, Kant explicitly stressed the primary character of synthesis, of the extension of knowledge, as compared with analysis when he says in the ‘Transcendental Deduction’: ‘The reader will easily enough perceive that the possibility of conjunction must be grounded in the very nature of this act, and that it must be equally valid for all conjunction; and that dissection, analysis, which appears to be its contrary, must, nevertheless, always presuppose it; for where the understanding has not previ-

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ously conjoined, it cannot dissect! 14. New, newly ‘made’ knowledge, as we might say, leads to a change in the historical level of synthesis, in what is now to be regarded as a ‘given’ concept with respect to which other (additional) – formerly new – judgements now become analytic judgements; for this concept is capable of a more extensive analysis at cognitive level than it used to be at cognitive level The relativity of the analytic-synthetic distinction is thus due to the change in our level of knowledge. Because for Kant, knowledge is essentially the same as the formation of concepts empirical concepts always reflect a certain level of knowledge. The distinction between analytic and synthetic judgements is therefore always related to a respective level of our ‘given’ knowledge and is fixed with regard to this. Thus, the classification of judgements as analytic or synthetic has the character of being relative to a level of knowledge. So we have the following consequence: The difference regarding the cognitive value of judgements results from a) the assumption of already given connections in the case of analytic judgements and b) the creation of new knowledge by a previously not given new connection (synthesis) that goes beyond what was already connected and conceptually ‘sedimented’ (knowledge). The reason for the peculiarity of the cognitive value of empirical judgments (as synthetic) is therefore that they impart new knowledge to us (as opposed to a mere clarification of what was given already) and not that the one type bears a relation to knowledge whereas the other does not. Moritz Schlick also emphasized this reciprocal connection between concepts and judgements, according to which our concepts change with knowledge. Thus in his Allgemeine Erkenntnislehre15 , he explicitly writes: ‘Judgments and concepts stand in a peculiar relationship. Concepts are linked together by means of judgments, since every judgment designates a joining of two concepts.’ And thus ‘a concept constitutes, as it were, appoint at which a series of judgment meet, namely, all those in which the concept occurs.’ (p. 46) And concerning definitions, Schlick holds ‘definitions of a concept are those judgments that, so to speak, put it in touch with the concepts nearest it. The concept can be locked upon as a brief expression of these connections.’ (ibid.) In the progress of scientific knowledge – because this is ‘never strictly selfcontained’ – ‘we constantly become acquainted with new properties, so that the concepts of these objects acquire in time an even richer content.’ (p. 47). Conceptual contents, to Schlick as to Kant, are relative to knowledge. And for this reason it is not ipso facto clear whether a judgement is a definition or knowledge. Schlick says: ‘Every judgment places a concept in relation to other concepts [...] If the concept in question is already familiar and defined, then we have an ordinary judgment. If this is not the case, then the concept is to be regarded as having been created by the judgment. The latter thus becomes the definition [...]’ (p. 47). For Schlick, definitions are basically also factual judgements: ‘theoretically, definitions do not occupy a special position’ (ibid.). With this, the difference between definitions and judgements also changes as knowledge progresses and is

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proven to be relative to knowledge. Insofar as the same linguistic term can stand for different conceptual contents in the course of the progression of knowledge, ‘one and the same sentence may, depending on the particular state of the inquiry, serve either as a definition or as an instance of knowledge’ (ibid.) 16. In a similar way, Willard Van Orman Quine later pointed out that it is basically the same whether we speak of the linguistic knowledge of concepts or of empirically founded knowledge universally shared by a language community.17 In this respect the distinction made by Quine between universally shared semantic knowledge and empirically attained additional knowledge roughly corresponds to the relativity of the distinction between given and constructed concepts in Kant’s philosophy, and to Schlick’s considerations on the cognitive relativity of definition and knowledge.18 Quine, like the other two, assumed that universally shared knowledge, knowledge about ‘concepts’, originally was additional knowledge. But after its acquisition (by the members of a language community) it is no longer a question of knowledge to be capable of evaluating statements based on such knowledge. In their view, this could also be interpreted as changing the ‘meaning’ of the terms involved.19 Thus the distinction between agreement to statements on the basis of knowledge universally shared by the language community and agreement on the strength of additional knowledge corresponds approximately to the understanding of the distinction between analytic and synthetic knowledge according to Kant, as expounded above.20 Once it has become part of general background knowledge (formerly) ‘new’ knowledge has nothing more than a clarificatory character. On closer inspection, Quine does not give up the distinction between analytic and synthetic; rather he places it in an epistemological context with regard to the cognitive value it has in a language community (knowledge universally shared by the members of a language community versus additional information), and in doing so he is building upon Kant’s original intention in making this distinction according to which there exist judgements of fundamentally different cognitive value with reference to a given level of knowledge.21 When Quine said that no real distinction can be made between the two types of judgement he took no notice of the fact that, with respect to a given level of knowledge, the distinction is already perfectly clear. It would thus appear that we can interpret linguistic meaning of descriptive terms as something that is relative to knowledge: It is only with respect to given knowledge that something is informative (synthetic) or not. That is to say, we always have to take into account the given cognitive horizon (of a certain person or language community) before we are able to say something about the merely ‘clarificatory’ or truly ‘knowledge-extending’ character of certain cognitive elements. Therefore we can conclude: concepts demarcate, and factual criteria of demarcation can become components of the meaning of concepts. One might even say that it is especially the most important factual insights into something that are later essential to the defining characterization of a thing. If we see this

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connection, then our position towards questions concerning conceptual features gets to be quite important factually, as they enter into factual questions. Therefore, linguistic meaning and factual demarcation cannot be separated and, with this, questions of meaning obtain a far greater factual importance than Popper was willing to concede to them. One might just as well say that in the discussion of conceptual questions we touch on factual questions too and, therefore, they are not fruitless. In the case of empirical concepts this may be relatively unproblematic, but it turns out to be rather far-reaching in the case of epistemological – and thus philosophical – concepts, because this bears on the question of the possibility of metaphysical knowledge. 3. T HE CRITERION OF FALSIFIABILITY ONLY GIVES A POSITIVE CHARACTERIZATION OF EMPIRICAL SCIENCE AND THEREFORE DEMARCATES METAPHYSICS ONLY NEGATIVELY.

Popper’s criterion of demarcation was intended to avoid problems in connection with inductive logic. It should enable us ‘to admit a system as empirical or scientific only if it is capable of being tested by experience’22. Popper therefore proposed as a criterion of demarcation not the verifiability but the falsifiability of the system concerned. To Popper’s mind it is not important that the system ‘shall be capable of being singled out, once and for all, in a positive sense’, but one has to demand ‘that its logical form shall be such that it can be singled out, by empirical tests, in a negative sense: it must be possible for an empirical scientific system to be refuted by experience.’ 23 For such ‘statements, or systems of statements, convey information about the empirical world only if they are capable of clashing with experience; or more precisely, only if they can be systematically tested, that is to say, if they can be subjected’ 24. For Popper, the problem of demarcation consists primarily in delimiting scientific complexes of statements from other non-scientific complexes through a characterization of empirical science25. At the same time, the delimitation from metaphysics is also important to Popper. But he only clarified positively what the characteristic feature of scientific statements is. Thus he gives us nothing more than a negative demarcation from everything else, which is non-science. Whether this is a demarcation from metaphysics or from something else is so far not clear. So it remains to be clarified from what Popper actually wanted to demarcate the scientific kind of knowledge.

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4. A CLOSER ANALYSIS OF THE CRITERION OF DEMARCATION SHOWS THAT IT IMPLICITLY CONSISTS OF TWO INDEPENDENT DIMENSIONS OF DEMARCATION.

A closer examination of the criterion of demarcation reveals that one can make a distinction that Popper has not made explicit, but that seems to form the implicit basis of his considerations and that allows us to make a multiple demarcation and thus to say something about the peculiarity of the other non-empirical kinds of judgements. There are two main characteristics of statements of empirical science: (1) first of all their logical form of refutability and (2) moreover refutability by experience. That is to say, empirical scientific (systems of) statements must not only be refutable in general but refutable empirically in the sense of methodical testability. Therefore the criterion of demarcation has, strictly speaking, two independent dimensions which Popper does not keep apart, thus incurring a risk of confusion. Popper’s criterion of falsifiability is usually referred to as the criterion of demarcation of scientific statements, although falsifiability as a logical property does not delimit science from metaphysics. For Popper unites two aspects in the criterion of falsifiability: one logical, the other having to do with highlighting a particular basis of validity, i.e. experience. That is to say, falsifiability, on the one hand, deals with the logical structure of statements and the logical relation of classes of statements and, on the other, with methodologically characterized statements of these classes that refer to experience in the sense of empirical testability.26 It is, however, extremely important to keep apart both aspects, the logical one and the one that characterises the basis of validity, because these are two different criteria. It is therefore called for that we take a closer look at the demarcatory capacities of the two dimensions: (1) On the logical form of refutabilty (falsifiability as a logical relation between classes of statements): Scientific statements – and systems of statements, in particular – are essentially universal statements (universal if-then statements); from them one can deduce certain negative existential statements (existential bans); hence they can conflict with certain statements by virtue of their logical form.27 It was exactly this feature that made the criterion of verifiability problematic. Another consequence is the logical ‘asymmetry between verifiability and falsifiability’28 that allows us by logical means of the ‘modus tollens’ to draw inferences from particular statements accepted as true to the falsity of a universal statement.29 This logical relationship between kinds of classes of statements initially has nothing to do with the fact that empirical statements have this feature. It is only in the ensuing examination – which is guided by the interest in scientific statements – that the investigation is confined to this subclass of statements, which is

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characterized by this relationship. It is typical of statements in empirical science that they belong to the classes of statements that stand in this logical relationship. If by falsifiability in general we understand this logical relationship, then the same fact might also be expressed as follows. Falsifiability in general and empirical falsifiability do not coincide. The first characteristic of scientific statements is therefore that by asserting something they simultaneously exclude something. Hence informativity always entails the possibility of refutability – in a case where what was excluded by the assertion is for whatever reason admitted, the assertion must be rejected. One might call this the logical aspect of falsifiability.30 But this is not an exclusive property of empirical statements alone. (2) On empirical falsifiability (reference to experience): Popper demands not only falsifiability in the sense of the mere logical possibility of refutability, but also in the sence of refutability by experience, empirical falsifiability. That is, scientific statements have to be such that they exclude not just any statements, but certain statements about our experience – basic statements – whose truth would imply the falsity of the respective scientific statement.31 The aspect of refutability by experience gives the statements empirical informative content and makes them empirically scientific. Demarcation is thus based on the logical property of refutability – falsifiability (or non-falsifiability) – in general, on the one hand, and on the particular kind of refutability by experience, the method of empirical testability, on the other. For only the two taken together define the realm of empirical science.32 Hence what makes any (informative) theoretical system empirically scientific is this reference to our methodical experience. Testability by experience ‘appears as a distinctive method whereby one theoretical system may be distinguished from another’33 Given this positive characterization of empirical scientific (systems of) statements as empirically falsifiable, we might be able to say something about the other systems of statements from which scientific statements are delimited respectively by the two dimensions of the criterion of demarcation. 1. The logical property of falsifiability delimits analytic from synthetic judgements. Synthetic judgements – metaphysical as well as empirical – are formally delimited by the common logical property of falsifiability (the logical possibility of being refuted). Therefore, the characteristic of falsifiability (testability) has to be regarded as a feature of all informative (synthetic) judgements. We also find this relationship in the case of metaphysical judgements, as in the case of empirical statements, where negations of metaphysical judgements also define contents that are excluded by them in the case of non-empirically testable (metaphysical) statements. Thus, for instance, metaphysical determinism (every event has a cause) excludes something (there is no event that has no cause); an uncaused – free – event of volition even though it is not empirically testable, would at least be something that is subject to this ban. That is to say, the fundamental logical asymmetry between verifiability and falsifiability, between

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logical provability and logical refutability, also exists in the case of – nonanalytic – metaphysical statements. Consequently, falsifiability distinguishes informative judgements from contradictions and tautologies and thus determines their synthetic character. 2. In opposition to this sole criterion of demarcation between empirical and metaphysical statements (which are falsifiable as well) is empirical testability (i.e. refutability though the property of being related to experience) which, however, does not coincide with falsifiability as a logical property.34 The difference between metaphysical and empirical statements is therefore solely due to the methodical difference in the type of empirical and non-empirical testability, it being an open question as to what might be regarded as testability in various cases. Since empirical testing is determined by ‘methodology’, there can also be criteria for the testing of metaphysical statements.35 If content is determined by the degree of falsifiability, then content and empirical content do not coincide, i.e. there are non-empirical but by virtue of their logical form nonetheless falsifiable (synthetic) statements that have to be considered as rich in content even though they are empirically empty. Thus we have to distinguish between testability and scientific testability. Which criteria of testability would have to be applied for metaphysical as well as for scientific considerations, respectively, is another question. 5. ANALYSED IN ITS DIMENSIONS, THE CRITERION OF DEMARCATION LENDS GREATER PRECISION TO KANT’S STATEMENT WITH REGARD TO THEIR COGNITIVE VALUE AND THE FOUNDATION OF KNOWLEDGE.

If we consider both dimensions of demarcation separately, it follows that (a) with the logical aspect of falsifiability or, minimally, the logical possibility of refutation, Popper is basically giving us a reformulation (and in some respects a reformation) of the Kantian distinction between analytic and synthetic judgements, for the criterion of falsifiability in the general sense of refutability delimits empirical from non-empirical judgements – but only from those nonempirical judgements that are, in addition, analytic. So on closer examination it turns out to be rather a criterion of demarcation between analytic and synthetic than between metaphysical and empirical judgements.36 (b) Furthermore we find that the explication of experience as scientific, methodically obtained knowledge (objective testability) is a reformulation of Kant’s distinction of the foundations of the validity of knowledge, the distinction between validity a priori and validity a posteriori – though (this being how it differs from Kant) not of experience in general but of scientific experience. However, only validity a priori is positively characterized in this way. Popper reconstructs validity by virtue of scientific experience with ‘the rules of the game “empirical science”’as their internal ‘logic’ 37 .

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But even if falsifiability must be regarded as a – logical – property of synthetic judgements that results from their informative character – and Popper in the main reformulates a criterion for synthetic, i.e. ampliative judgements – something else becomes apparent that Kant had considered to be negligible. In making his distinction Kant was only looking at true judgements, whereas Popper takes into account that when making judgements we never know whether they are true. By making falsifiability the criterion of demarcation, Popper therefore connects two insights: (1) the distinction between informative and non-informative judgements

and: (2) the independence of informativity and truth. Therefore, all synthetic judgements as cognitive claims can also be false without our being able to know it. Syntheticity – informational content – of judgements and their truth are thus independent properties. That is to say, informativity and possible falsity must be able to coincide. Hence, synthetic judgements are not ipso facto extensions of knowledge as Kant assumes, but are only possible extensions of knowledge. A synthetic judgement is an extension of knowledge only in so far as it is true. This property of being merely a possible extension of knowledge finds expression in the logical structure of synthetic judgements: Syntheticity – or informativity – always means: there exist logically possible classes of events that are incompatible with the assertion in question. With the insight that synthetic judgements are always possible extensions of knowledge but that this is not guaranteed, synthetic character (informational content) and falsifiability coincide both for empirical and metaphysical statements. As a result of the foregoing considerations, we can conclude that: 1. Meaning and factual demarcation do not contradict each other.

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2. The criterion of demarcation can well be interpreted as a criterion of meaning. There is no conflict here if one takes into account the connection between meaning and cognition. 3. Clarifications of concepts originate in factual judgements (in cognitive claims). 4. Philosophical and especially epistemological concepts are therefore such that they are also based on cognitive (epistemic) claims, albeit not to empirical knowledge.

6. INASMUCH AS EPISTEMOLOGY ELUCIDATES CONCEPTS, THE CONNECTION BETWEEN THE CLARIFICATION OF CONCEPTS AND JUDGEMENTS OF KNOWLEDGE MEANS THAT THERE MUST ALSO BE A DIMENSION OF COGNITIVE VALUE IN EPISTEMOLOGY.

In conclusion, let me return to the appreciation of epistemological considerations within the framework of a science-oriented philosophy as professed by Schlick. Summing up our deliberations so far we arrive at the question of what this means for the question as to what extent epistemology (or philosophy as a whole) possesses a cognitive claim. The modification of Popper’s considerations on the criterion of demarcation allows a more precise determination of the peculiar characteristics of metaphysical judgements. To my mind, they also permit a critical investigation of the farther-reaching assertion that philosophical reflection is nothing more than a mere analysis of concepts. If we consider the epistemological problems that occupied Schlick from the beginning, we realize that they concern the philosophical elucidation and justification of the empirical sciences’ cognitive claim, especially the understanding of the conceptual apparatus we need for the description, elucidation and explanation of all that can be termed knowledge or scientific cognition.38 Along with the basic syntactic and semantic concepts of ‘meaning’, ‘reference’, ‘fulfilment’ and ‘truth’, these would include the conceptual instruments of epistemology like ‘existence’, ‘cognition’, ‘experience’ and ‘reality’ or the question as to the aim of knowledge. In his Allgemeine Erkenntnislehre Schlick still regarded the elucidation of problems related to epistemological realism as factually meaningful and important, questions which under the influence of Wittgenstein he later came to consider as questions of merely conceptual clarification to which no synthetic cognitive value is attached. The connection between the extension and the mere clarification of knowledge as described above should have made it clear that it does not help if, in the treatment of philosophical problems, one withdraws to the position that the elucidation of epistemological questions is nothing more than an analysis of concepts. For analysis, as we were able to see, refers to previous synthetic acts of

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judgements except in the case of abbreviations introduced for the sake of economy of language If what Schlick says about concepts in general is also true for epistemological concepts, then definitions and judgements must in principle refer to each other in this field, too. This can only be avoided if we are willing to go as far as Wittgenstein and deny that epistemological questions have any cognitive value. Then, as a consequence, there can no longer be philosophical concepts or definitions thereof. Cognition must then really be replaced by pointing. Beyond verificationism there is, however, no longer any need to do this, especially since this assumption about the nature of philosophical considerations is a presupposed metaphysical thesis. Hence those who are unwilling to banish philosophy completely to the silent world of pointing, and who concede to philosophy at least the status of concepts we must presuppose for the investigation of knowledge, we cannot avoid conceding a status of knowledge to them as well. To my mind, the proposed improvement or modification of the basic concept of falsificationism gives us a good starting-point for the treatment of epistemological considerations, especially since it is also an alternative to verificationism. The latter should be acceptable to a scientific philosophy if one gives up Popper’s pretence to a methodology that aims to standardize scientific method in a way that is probably incompatible with what we know about scientific progress. Epistemological judgements and concepts can thus also be regarded as rich in content (factual), even though they are not empirically factual because they are not empirically falsifiable. This, of course, raises the question as to whether we are not reanimating a synthetic apriori though this approach. As far as I can see, this cannot be claimed in the Kantian sense because, for him, a synthetic apriori would have to be an apodictic judgement that must necessarily be decidable by pure reason. Metaphysical judgements as judgements which are not justifiable by experience but formulated with a cognitive claim can only be tested in view of their explanatory capacity as conditions of empirical knowledge in the light of alternatives and in view of their consistency with other philosophical considerations. Therefore, they are to be regarded as metaphysical hypotheses. An acceptable system of philosophical concepts can only be one that is as complete and coherent as possible and that also integrates all philosophical solutions to problems in a consistent manner.

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NOTES

1. 2. 3. 4.

5. 6. 7.

8. 9.

10. 11.

12. 13.

14.

15. 16.

17. 18.

19.

Karl Popper, Logic of Scientific Discovery (LD) (orig. Logik der Forschung (1935)), New York 1965, Ch. I. Paradigmatic for this are especially Rudolf Carnap’s expositions in: Scheinprobleme in der Philosophie (1928), repr. Frankfurt am Main 1966. Logic of Scientific Discovery, p. 40 fn. *3. Cf. K.R. Popper, Conjectures and Refutations. The Growth of Scientific Knowledge (1963), especially part XII of the introduction and passim, as well as Objective Knowledge. An Evolutionary Approach, rev. ed. Oxford (Clarendon) 1979, p. 309ff. und p. 122ff. Cf. (together with the works quoted in fn. 4 above) ‘Three Views Concerning Human Knowledge’, in his Conjectures and Refutations, p. 97ff. Conjectures, p. 20. Conventions need not be the result of explicit stipulations as claimed by Carnap for ‘postulates of meaning’ in artificial languages. For natural languages this will, rather, be the exception. Here we are dealing with conventions in the sense of historically crystallized habits in the use of language that were never defined explicitly. David Lewis tries to interpret conventions as the result of problems of coordination (cf. D. Lewis, Konventionen). But the basic idea in this is also: ‘It is a platitude that language is ruled by convention. Words might be used to mean almost anything; and we who use them have made them mean what they do because somehow, gradually and informally, we have come to an understanding that this is what we shall use them to mean. We could perfectly well use these words otherwise’. (Lewis, Konventionen, p. 1) Conventions are regularities of behaviour (cf. Lewis, Konventionen p. 59). Conjectures, p. 20. Popper, Objective Knowledge, p. 309. Popper regards the position of essentialism as an erroneous view commonly held in the history of philosophy. Cf. Popper, Objective Knowledge, p. 122f. Objective Knowledge, p. 309 f. Objective Knowledge, p. 310. Popper also devotes an entire chapter of his autobiography to this question. Cf. Popper, ‘Autobiography’ in: Paul Artur Schilpp (ed.) The Philosophy of Karl Popper, Book I, La Salle, Illinois (Open Court), Ch. 7: ‘A Long Digression Concerning Essentialism: What Still Divides Me from Most Contemporary Philosophers’, p. 12-23. Kant, Critique of Pure Reason, A 8 (‘Begriff, den ich schon habe’). Kant says that this distinction is ‘in Ansehung der Kritik des menschlichen Verstandes unentbehrlich’ and must be regarded as ‘klassisch’ . (Kant, Prolegomena, § 3). Critique of Pure Reason (1781/1787), B 130 (my italics): ‘Man wird hier leicht gewahr, daß diese Handlung ursprünglich einig, und für alle Verbindung gleich geltend sein müsse, und daß die Auflösung, Analysis, die ihr Gegenteil zu sein scheint, sie doch jederzeit voraussetze; denn wo der Verstand vorher nichts verbunden hat, da kann er auch nichts auflösen.’ Moritz Schlick, General Theory of Kowledge, Wien-New York (Springer) 1974. (orig. Allgemeine Erkenntnislehre, Wien (Springer) 1918), p. 45. The dynamic element in Schlick which changes the content of concepts was also pointed out by Haller in: ‘Erkenntnisprobleme bei Moritz Schlick’, in: Zurück zu Schlick. Eine Neubewertung von Werk und Wirkung. (ed.) Brian McGuiness, Vienna (Hölder-Pichler-Tempsky) 1985, p. 35. Word and Object, Cambridge, Mass. 1960, ch. II. Cf. my analysis in: Moderner Relativismus, Tübingen (Mohr Siebeck) 1990, Ch. II. Cf. ch. IV: ‘Wissen und Sinn’ of my book: Benennung, Sinn, Notwendigkeit. Eine Untersuchung über die Grundlagen kausaler Theorien des Gegenstandsbezugs, Frankfurt am Main (Athenäum) 1987, p. 170-177. Quine (Word and Object, § 9, p. 38) himself says that one might interpret the situation after the aquisition of some additional knowledge C as change in meaning of a sentence S. We could ask: “Now couldn’t we just as well have said, instead, that on acquiring C, men have found it convenientimplicitly to change the very ‘meaning’ of S”?

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20. With the difference that this is referred to subjectivity according to Kant, which was replaced by Quine with the respective language community. 21. Interesting in this context are remarks made by Dudley Shapere about changes in scientific language. According to Shapere, changes in science also involve ‘the building of well-founded information into our descriptive vocabulary’ (Shapere, ‘Reason, Reference, and the Quest for Knowledge’, Philosophy of Science 49, 1982, p. 14). We have ‘a process of gradual reformulation, in the light of what we have learned’ (p. 13). This is a process of ‘internalizing of relevant considerations’ (ibid.). 22. Logic of Scientific Discovery, p. 40. 23. Logic of Scientific Discovery, p. 40. 24. Logic of Scientific Discovery, p. 313f. 25. ‘The ‘problem of demarcation’ is what I call the problem of finding a criterion by which we can distinguish the statements of empirical science from non-empirical statements’. Popper, ‘Conjectural Knowledge; My Solution of the Problem of Induction’ (1979) in ch. 1 of: Objective Knowledge, p. 1 2 f n . 19. 26. That we are dealing with two aspects here becomes clear when Popper explicitly talks about empirical falsifiability, something that would only be analytic if falsifiability were ipso facto empirical falsifiability. Just because Popper is always concerned with empirical falsifiability he mostly uses both terms interchangeably. 27. That is why nomological statements as we find them in the sciences not only assert something but simultaneously exclude something. So, for instance from the universal if-then-statement ‘All planets describe orbits around the sun’, there follows the negative existential statement ‘There exists no planet that does not describe an orbit around the sun’; i.e., such nomological statements exclude the occurrence of certain events. 28. Logic of Scientific Discovery, p. 41. 29. By taking recourse to the Aristotelian apagoge, Schopenhauer had already pointed out that one can reap the benefits of this asymmetry in order to oppose potential falsifiers to statements. Schopenhauer said that against an universal statement one needs ‘nur einen einzigen Fall aufzustellen, zu dem der Satz nicht paßt, und derselbe ist umgeworfen: ein solcher Fall heißt Instanz [...] Z.B. der Satz: “Alle Wiederkäuer sind gehörnt” wird umgestoßen durch die einzige Instanz der Kameele. Die Instanz ist ein Fall der Anwendung der allgemeinen Wahrheit, etwas unter den Hauptbegriff derselben zu Subsumirendes, davon aber jene Wahrheit nicht gilt und dadurch ganz umgestoßen wird’. Schopenhauer, ‘Eristik’, in: Aus Arthur Schopenhauer’s handschriftlichem Nachlaß. Abhandlungen, Anmerkungen, Aphorismen und Fragmente. Herausgegeben von Julius Frauenstädt. Leipzig 1864, p. 26. There we also find the remark that even potential falsifiers are not certain. In the quoted passage Schopenhauer continues: ‘Allein dabei können Täuschungen vorgehen’. 30. This aspect of refutability (the existence of the logical possibility of refutation) coincides with the informative content of a statement. That is to say, informativity always involves falsifiability. 31. Experience in this context always means methodically acquired experience (cf. Logic of Scientific Discovery, p. 53ff.). By empirical we therefore understand ‘was durch die empiristische Methodologie, durch die Theorie der “Erfahrung”, erst genauer zu präzisieren ist’ (Popper, Die beiden Grundprobleme der Erkenntnistheorie, Tübingen (Mohr Siebeck), 1979, p. 360). Therefore, there is a need for an independent elucidation of the ‘problems concerning the empirical character of singular statements’ (the basic statements) Logic of Scientific Discovery, p. 43. For their scientific character cannot be grounded in their empirical falsifiability alone. 32. This difference seems to be what Popper is emphasizing when he says that ‘empirical science seems to be characterized not only by its logical form but, in addition, by its distinctive method’ (Logic of Scientific Discovery, p. 39), the reference to experience through methodical tests. 33. Logic of Scientific Discovery, p. 39. 34. That the logical characteristic of falsifiability alone – the feature of refutability – is in general not sufficient as a criterion for the characterization of empirical science is pointed out by Popper in connection with the difficulty, ‘that there must be many theoretical systems with a logical structure very similar to the one which at any particular time is the accepted system of empirical science’ (Logic of Scientific Discovery, p. 39). That is to say, we are able to give a factual

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description of distinct possible worlds which as descriptions really exclude something. But it is not sufficient that statements are informative (and hence exclude something); they must moreover be empirically testable (exclude something empirical), for only then are they of the kind that describes our world. Not the synthetic character – the informative content – alone is thus decisive, but also the types of possible instances of testability. That is to say that a scientific system that intends to describe our world should not only be informative but also true; at least it should claim to be true. Therefore, what distinguishes empirical science as a form of knowledge from other forms of knowledge is methodically obtained experience, objective empirical testing. Later, Popper also thought about possible ways of testing metaphysical considerations. On this cf. ‘On the Status of Science and of Metaphysics’ (1958) in: Conjectures and Refutations, especially p. 193-200. For only with analytic statements can one show in a way which can be decided by logical analysis that for such statements there exist no possible falsifiers. When Popper, for instance says: ‘the statement, “It will rain tomorrow” will not be regarded as empirical, simply because it cannot be refuted’ (Logic of Scientific Discovery, p. 41), the demarcation is only due to the fact that the ‘logical form’ of a system ‘shall be such that it can be singled out by means of empirical tests in a negative sense’ (Logic of Scientific Discovery , p. 41; my italics). The aspect of testability by experience does not play any role here at all. Another example would be a statement like: ‘Entrepreneurs have productive factors at their disposal.’ If one takes into account that an entrepreneur is by definition someone who has the productive factor capital at his disposal, then it follows that this statement is analytically true and insofar not empirically scientific. But in the same manner, one could delimit informative metaphysical from merely metaphysical elucidations of concepts. As is well known, even Kant pointed out that many supposed instances of metaphysical knowledge are nothing but concealed analyses of concepts. Logic of Scientific Discovery, p. 53. Cf. also Haller, ‘Erkenntnisprobleme bei Moritz Schlick’, p. 34.

Institut für Philosophie Universität Rostock 18051 Rostock Germany [email protected]

DAGMAR BORCHERS

“LET’S TALK ABOUT FLOURISHING!” – MORITZ SCHLICK AND THE NON-COGNITIVE FOUNDATION OF VIRTUE ETHICS

1. LET’S TALK

ABOUT

VIRTUES!

My intention here is to make a case for the moral philosophical work of Moritz Schlick which, in my opinion, has not been adequately appreciated in the discussion between two different groups within analytic philosophy, i.e., those who prefer virtue ethics and those who do not. One aspect of their controversy is the rating of the virtues within analytic moral philosophy. Protagonists of virtue ethics like Philippa Foot claim that the analysis of virtues has been neglected for a long time, mainly for methodological reasons, and that the necessary revival must be seen as starting something totally new within the tradition of analytic ethics. But, keeping Schlick in mind, it seems as if there is no need for a revival – a promising start has already been made. The justification of my claim proceeds by the following steps: The first step presents Foot’s argument and my own. The second step concentrates on Foot’s historical error. Referring to the ethical studies of Moritz Schlick, I want to show that – contrary to a widespread assumption – there was a profound interest in the relationship between happiness and moral practice within the Vienna Circle. The third step will reveal that Foot’s attemption is itself flawed and, therefore, does not offer a promising route for those who want to do virtue ethics. The fourth step finally takes us in the right direction, i.e., to Moritz Schlick’s inspiring influence concerning the perspectives of virtue ethics within analytic philosophy. This is our program. Let’s start with Foot’s argument. Foot’s Argument There is an increasing number of moral philosophers who have noted a lamentable neglect of virtues within analytic moral philosophy. One of the most vehement pioneers of this development within analytic ethics has been the English 95 F. Stadler (ed.), The Vienna Circle and Logical Empiricism: Re-evaluation and Future Perspectives, 95–106. © 2003 Kluwer Academic Publishers. Printed in the Netherlands.

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philosopher Philippa Foot. In her well-known paper “Virtues and Vices” she makes the following claim: For many years the subject of the virtues and vices was strangely neglected by moralists working within the school of analytic philosophy. The tacitly accepted opinion was that a study of the topic would form no part of the fundamental work of ethics; and since this opinion was apparently shared by philosophers such as Hume, Kant, Mill, G. E. Moore, W. D. Ross, and H. A. Prichard, from whom contemporary moral philosophy has mostly 1 been derived, perhaps the neglect was not so surprising after all.

My Argument In referring to the moral philosophical work of Moritz Schlick, I want to show the following: (1) Foot’s interpretation is historically false. It can be shown that there is a deep interest of philosophers of the Vienna Circle in the virtues and especially in questions concerning possible ways of flourishing. One of the most prominent example is Moritz Schlick. In his ethical work we can find a kind of NeoHumean virtue ethics. It is based on (a) noncognitive meta-ethics and (b) a descriptive theory of action. (2) This analysis is methodologically false. The background of this misinterpretation is a fixed opinion on how a virtue ethics conception should look. When elaborating her own position, Foot assumes that without criticizing (a) and replacing it by an cognitive view and criticizing (b) and replacing it by a unified conception of practical reason, there will be no working virtue ethics. I will show that her arguments in favour of this project are not convincing. In fact, both the cognitive meta-ethical basis (a) and the non-Humean theory of action (b) turn out to be flawed. Furthermore we will see, that with regard to the content of the theory of the virtues, there are great similarities between Schlick and Foot, despite their differences in (a) and (b). The result of this will be the following. Whoever wants to convince other moral philosophers of the outstanding potential of virtue ethics has to present an elaborated theory of the virtues. As we see, a practicable start has already been outlined by Moritz Schlick. The consequence will be the quest for an elaborated noncognitive virtue ethics build upon the foundations laid by Hume and Schlick. The prospects for such a project are promising. I will conclude with a number of proposals on how such a theory could look. But the next step must be to correct the historical assumptions made by Foot.

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2. THE HISTORICAL CORRECTION OF FOOT’S THESIS: SCHLICK AND THE VIENNA CIRCLE

Ancient Ethics and the Vienna Circle Anyone familiar with the work of the members of the Vienna Circle knows that, although they rejected the possibility of talking scientifically about normative questions, they were nonetheless very interested in moral problems. Even radical noncognitivists like Carnap or Wittgenstein were deeply convinced that ethical considerations – formulated as questions “How should I live? What sort of person should I intend to be?” – are the most important ones in our life. In answering them, we do not have to put up a catalogue of moral duties or complicated abstract considerations. These are not questions that call for a theory. Instead, we are asking for practical advice, looking for examples. As Manfred Geier has pointed out, this anti-theoretical approach to ethical problems, together with the deep conviction that moral obligations must be compatible with our inherent search for happiness clearly prove that members of the Vienna Circle could identify with ancient moral philosophy:

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When Karl Popper spoke about morality and ethics, he referred to Socrates. Confronted with a threatening fate, Ludwig Wittgenstein turned to Stoicism for orientation in his intellectual efforts. Schlick responded to ‘ethical questions’ as an eudemonist whose primary interest was pleasure, taking recourse to Socrates, Aristippus and Marcus Aurelius. Otto Neurath’s holistic social ethos revealed shades of an Epicurean happiness where a certain joie de vivre figured centrally.2

So we have to stick to the fact that there is at least, in principle, no gap between ancient virtue ethics and the outlook on morals of the first generation of analytic philosophers – on the contrary, there seems to be a certain affinity.

Moritz Schlick and the Question for Morals and Happiness One prominent example is Moritz Schlick. Although Schlick was not concerned with a foundation of morality in the quasi-scientific, theoretical way ethics is done today, we should now be permitted to take an analytical look at the formal structure and the metatheoretical implications of his ethical theory. Accordingly, his conception, reconstructed as it is put forward in his two studies in ethics3, is based on two columns: noncognitive meta-ethical assumptions and a descriptive theory of action. (a) A noncognitive meta-ethics: The background of his conception is an empiricist epistemology that acknowledges only two forms of cognition. Sensible statements are either analytic a priori or synthetic a posteriori. In the first case, cognition may be seen as undoubtable, but it will tell us nothing about the real world. In the second case, we will have a cognition about the world, but it will have only hypothetical character. Statements that are neither analytic a priori nor synthetic a posteriori must be regarded as senseless. Senseless statements are pseudo-statements; they can’t even be true or false. Normative judgements belong to the class of statements that are neither analytic priori nor synthetic a posteriori. Being senseless in principle, they do have two characteristics: First, they do not depict a cognition but an emotion, a desire or an interest. Second, they are not descriptive but prescriptive. This means that a scientifically respectable moral philosophy can only be done as a descriptive ethics that refrains totally from normative statements. (b) A descriptive theory of action: According to Schlick, the main task of ethics is to deliver a causal explanation of moral behaviour. Before it is possible to answer the question “Why does man act morally? ” it must be clear why he generally acts to begin with, how human action works. The premise of the analysis is that each act is constituted by an inner disposition (“natural or artificial desires”) and an outer effect (“motive”). The result of Schlick’s analysis is the so-called “law of motivation”, which states that the motive that turns out to be the strongest one will determine the action. Taking the action of drinking water as an example, thirst will be a desire; the sight of water the motive. If the thought of drinking is the most powerful one among other competing ideas, it will there-

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fore be decisive for the action itself. Reasoning has no direct influence on action. Only insofar as it creates a desire that turns out to be the most craving one does thought direct action. Principally, action is based on the pursuit of pleasure. The latter is synonymous with the pursuit of happiness, even if we can’t explain in detail what happiness means. All we can say is that it does not only include actual pleasure, but also the hope for future enjoyment. The art of life consists in the maximazation and harmonization of both components. What are the implications for morality and moral action? (c) Schlick’s virtue ethics: Contrary to Foot’s assumption, we will discover a profound virtue ethics-conception within the work of Schlick, focused on the interrelation of morals and happiness. The first thing we have to understand is: How is morality possible in general? Morality will only have a chance to work if it is directly rooted in the structure of human needs. Moral motivation will be solid, if– refering to our law of motivation – the pleasures of the imagination of moral action correspond to the pleasures of the realization of moral action itself. In other words: moral action must be a real pleasure. Fortunately, we are able to say: Virtue and happiness are compatible. That we are capable of maintaining a certain harmony between virtue and happiness is due to a widespread experience. The common roots of virtue and happiness are the social desires (as part of the natural desires) we find in every individual. Without the company of other people, happiness is hardly imaginable. But happiness has its price. We are urged to shape our desires in a way that makes us sociable. Experience shows that being virtuous is the best way to happiness. An unfortunate constellation of desires will prevent the enjoyment of life. This is why it proves necessary to tame some of them and to strengthen others. This kind of education and practice aims at the harmonization of the desires and the development of our character. To be virtuous means to act morally without reasoning, beyond the pressure of sanctions or conscience. The more virtuous one is, the easier it is to do the right thing. The most important moral virtue is justice; other important moral virtues are benevolence and friendship. All these virtues will make happiness more probable, but not certain. Experience shows that chance and fate, as well as the amorality of others, may thwart the pursuit of happiness and limit the radius of the virtues. But, all things considered, they are the best recipe for flourishing. What about the epistemological status of virtues? Moral virtues represent the experience an individual or a society (as a group of individuals) has made with different kinds of human behaviour. To say that something is good or should be done expresses the positive experience society has had with this special kind of action. Based on social experience, moral norms and the relevant virtues are principally objects of modifications and change over years and centuries. Generally, acting morally is defined as being the opposite of acting thoughtlessly. For Schlick, there is only one fundamental moral insight – “Be ready for happiness” or, more elegantly, “Be inspired”: 4

Whoever is able and ready to share in the joys of life is invited to them.

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Characteristics of Schlick’s Conception Now, what are the results of this investigation of Schlick’s virtue ethics? We can say that his conception is ... Naturalistic; as it is willing to integrate the explanation of human action and the general function of morality into a biological description of human behaviour and the world; Empiristic; as it works on the basis of empirical theories and refers to common social experience for its explanations of human behaviour and the content of certain moral principles; Consequentialistic; as it is embedded in an neo-Humean consequentialism – criterion of moral actions and principles are their (good) consequences for agents and their surroundings; Noncognitive; as it is based on a noncognitive meta-ethics and as it refuses to impose moral norms or a binding set of virtues; although it is at the same time able to provide a general moral principle – morality has to improve our lives. And it fulfills two central claims of a “real” theory of virtue ethics. Schlick puts the virtues in the centre of his conception and formulates the decisive moral questions the way virtue ethics does: “How should I be?” and “How should I live? ” Its fundamental question is not ‘What is demanded of me?’ but ‘How must I live to be happy?’ It has its source in the desires of the individual, of the agent himself, and thus bears the character not of demand but of desire.5

Conclusion For this reason, it is absolutely puzzling to hear Foot say that the topic of the virtues has been neglected ever since within analytic philosophy and, moreover, that this neglect has programmatic causes. By putting the stress on happiness and pleasure, Schlick resolutely turned against modern justifications of a pure, categorical ethics of obligation which excludes the tendencies of empirical subjects to seek happiness and to make them responsible for the tender death (euthanasia) of all morals. Instead of adhering to the rigorous Kant and other advocates of 6 an abstract morality based on imperatives, Schlick recalls the ancient art of life. Hence it seems as if, according to Foot, only the fulfillment of very special criteria guarantees that a virtue-ethical theory is “real”. So let’s have a look at what she herself proposes.

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3 . THE METHODOLOGICAL CORRECTION OF FOOT’S THESIS: FOOT’S CONCEPTION AND ITS PROBLEMS

Foot’s Conception So why are Hume and Schlick not considered moral philosophers doing virtue ethics? The reason is not the disapproval of (c), but the disapproval of (a) and (b). Foot claims that without abolishing (a) and (b) there will be no satisfying virtue ethics. Criticizing (a) means submitting a cognitive meta-ethical basis. Its two decisive arguments are, first, a semantic argument and, second, the conception of “Aristotelean necessities” (which originally had been developed by E. Anscombe). Moral judgements can qualify as objective insofar as the semantic features of the word “good” and the word “man” do provide the decisive criteria for a good person or a good action. Generally, the relevant criteria of what it means to be good are not up to the speaker, but are determined by the function of the object itself – the descriptive meaning of “good” is variable, not a matter of choice. As the purpose of man is in principle explicable, there exists a chance to determine criteria for a good action or a good person. The characteristics of a flourishing human life determine the purpose of man and apply a strict standard to the good which, in principle, could be recognized by any intelligent agent. For Foot, it is obvious that a behaviour that undermines the fulfillment of these needs can never be called a good one. Moral procedures are part of the pursuit of pleasure, the fulfillment of human desires. Without these procedures, leading a good life would be impossible. All in all, someone who does not understand that being moral is as necessary for human beings as hunting in packs is for wolves, is suffering from a cognitive deficit. Criticizing (b) means submitting an anti-Humean theory of action. Foot accepts the fact that moral judgements are practical – they aim to direct our actions. Nevertheless, in her eyes the noncognitive reconstruction of moral judgements is flawed: in fact, a moral judgement does not depict a desire or a certain interest, but a cognition. The foundation of a moral statement is an insight into the necessities of human life or other causal relations. The recognition of the brute facts of human nature provides reasons for moral acting. The statement “Torturing children is bad” is based on the cognition that such a behaviour hurts the child mentally and physically and will in no way contribute to a good human life. It is the cognition that is basic, so there needn’t be added a special interest in the child’s not being beaten. Men act for reasons. Much of what has to be said here will depend on a feature of the operation of human beings to which Aquinas drew attention, when he said that while animals perceive things that are good and go for them, human beings go for what they see as good. […] In fact the

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truth and great importance, of what Aquinas said comes out in the recognition of the whole conceptual structure belonging to the idea of human action and desire; as for instance the fact that they can say why they want something, can conduct practical 7 reasoning, and defend a choice.

(c) Foot’s virtue ethics: Both components together motivate her special conception of the virtues (c). Acting virtuously means doing the right thing for adequate reasons. The function of the virtues is to correct our motives - supporting those that are too weak and limiting those that are too strong. They adjust motivational deficits and enable us to do the right thing each one standing at a point at which there is some temptation to be resisted or deficiency 8 of motivation to be made good.

A life without virtues will not be a good one; there will be no flourishing without them: Nobody can get on well if he lacks courage, and does not have some measure of temperance and wisdom, while communities where justice and charity are lacking are apt to be wretched places to live, as Russia was under the Stalinist terror or Sicily under the Mafia.9

Foot’s Problems Foot’s own conception claims to be the one that is based on adequate metaethical considerations and a well-founded theory of action. I argue that it is not. Let me briefly explain why. First, there are objections to Foot’s cognitive meta-ethics. Foots’s way of making the nature of human beings the basis of morality seems to be a methodologically daring enterprise. To be successful, one must be able to determinate the relevant characteristic features of human beings precisely and free of doubt in order to be able to say, in a second step, what kind of behaviour we should perform. But there is no reason to be too optimistic. Indeed, the facts about human nature and the necessities of the species do not provide the purpose of man and, furthermore, no standard of the good. First, we do have a problem of choice: It is not obvious which features will characterize our species. Without doubt it will only be our genes, but they do not give us any information as to how to act and what to do. Other features like the ability to speak, to think or to construct things will also apply to some mammals. Second, we have a problem of relevance; Even if it were possible to determine the relevant characteristics, their normative relevance would be questionable. Facts about our species do not lead to the consequence that we should act morally. They may also suggest that we follow an immoral strategy. In sum, then, since knowledge about human nature is not capable of providing definite normative insights, the claim that moral judgements provide cognition seems to be untenable.

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Second, we also have some objections to Foot’s theory of action, for nearly the same can be said about her conception of practical reasoning. First, reasonable thinking is not necessarily moral thinking. McDowell has pointed out10 that a reasonable wolf will immediately see that hunting in packs may be alright – for the others. He himself would be better off if he would not join the hunting but only the eating pack. Therefore, we do have the problem of immoral action often being a much better strategy for a happy life. Even if we concede that, all in all, life will be better in harmony with others, this insight will not prevent numerous “minor” immoral activities. Second, it is not knowledge that leads to action, but an interest: A cognition alone will not help us, as we can easily see in cases of giving up smoking or a diet. It is not knowledge that smoking will be destructive to our health, but feelings like fear or ambition. So we have to realize: Neither facts about human beings nor rational thinking prove that we should act morally. Although it is possible to support a moral standard through reasonable arguments or certain facts about humans, it must be clear that no one is forced to accept the standard by simply being human: […] it is one thing to say that by calling a creature a man we imply that he belongs to a species having certain capacities, and quite another thing to say that by so calling him we imply that he belongs to a species whose specific good is of a certain kind. [...] Similarly, if ‘horse’ is used as a functional word, meaning ‘charger’, a horse that throws his rider becomes eo ipso a bad one; but the horse might say to himself ‘I am not trying to be a horse in that sense; I am only a solid-hoofed perissodactyl quadruped (equus caballus), having a flowing mane and tail’, and proceed to throw his rider without offence to anything but the rider’s standards. [...] The horsebreaker’s art would be easy, if one could 11 turn horses into chargers by definition.

Thus we must conclude that, contrary to Foot’s intentions, moral action still is an explanandum, not an explanans. Nevertheless, Foot’s conception of the virtues is a very instructive one and there are no direct contradictions to Foot’s virtue ethics as such. Although we will say that (a) and (b) are both defective, we can discover a lot of similarities between Foot and Schlick concerning their conceptions of morals and virtues. Both see morality as a source of happiness and virtues as promising tools for flourishing. Moral action must be a source of happiness, for otherwise it will not be possible. They both insist that the virtues are needed to shape our motives and enable us to react in a competent manner when confronted with a moral problem. That means, that conerning (c), the core of the virtue ethics-conception, they are very close to each other. My suggestion is to follow the path they sketch, but with the meta-ethical background provided by Schlick. So finally, let’s have a look at the perspectives of virtue ethics.

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4. L ET ’ S T ALK ABOUT V IRTUES – THE W AY S CHLICK D OES !

After all, it seems to be the most promising strategy to follow Schlick when choosing the foundations of virtue ethics. So I will conclude by presenting some metatheoretical suggestions. An adequate virtue ethics-conception should be … Naturalistic: It turns out that the most fruitful background of this examination would be a naturalistic conception of the world. What does this mean? It means seeing the world as a continuous system that exists independently from human perception in time and space. The world as a whole and all its subsystems are the object of an universal evolution. In principle, it is possible to gain insight into the structure of world, how certain things in nature interrelate and how they work. For this purpose, the empirical sciences have proven to be the best tool. Morality has to be seen in the context of human evolution, too. It is part of the history of human evolution and human culture. As such, morality is a legitimate object of scientific research. For me, this is not a point of disagreement between Foot and Schlick as well as the following two items. Empiristic: Our moral life contains a vast amount of heterogeneous phenomena, of which the virtues form a subset. Thus, the examination of the virtues is embedded into a scientific project seeking to improve the understanding of human development. As a descriptive enterprise, ethics is well-advised to bear in mind the methodological standards of the empirical sciences. As an empiristic enterprise, it should be grounded in our social and moral experience and depict it. In addition, its results should at least not be incompatible with such widely accepted theories in anthropology, sociology and biology as, for example, the theory of evolution. Consequentialistic: Morality has to be seen as part of the human pursuit of happiness. An action can qualify as morally good if it is the one with the best consequences. The best consequences are those that will support the pursuit of happiness and minimize suffering. A character trait or a disposition can count as a virtue if it enables flourishing and supports personal or social welfare. Virtues allow for cooperation, shorten moral decision procedures and, all in all, make an indispensible contribution to the stability of morals. Their instrumental function makes them useful. At this point, Foot’s inspiring remarks on the function of virtues should be taken into account. Noncognitive: Many moral philosophers have tried to develop a cognitive foundation of virtue ethics, for example Aristotle, Aquinas and, nowadays, not only Philippa Foot but also Martha Nussbaum, John McDowell and Alasdair MacIntyre. As I have shown elsewhere12, none of these attempts is really convincing. This is why I vote for a noncognitive meta-ethics (though it’s absolutely clear that this topic needs additional discussion), and it seems

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to me that Schlick’s version is a fitting one. A consequentialistic background will suffice to promote certain relevant virtues. There is no need for a cognitive foundation. For many reasons the concentration on the moral agent, especially his character, seems to be reasonable. Character plays an important role concerning the perception of a situation as morally problematic with certain relevant features, as well as concerning the reaction of the agent and, finally, his will to make the best of this situation for all participants. It is important to keep in mind that moral questions are embedded in general considerations of one’s identity, personal development and life plans. Obviously there are degrees of moral competence and moral knowledge, and it seems promising to ask what that precisely means. Within such an analysis, virtues and character will play a key role. Conclusion There might be a need for intensive study of virtues. We are even willing to concede that this enterprise will be a real improvement for analytic moral philosophy as it reintroduces a variety of neglected topics into modern ethical theorizing. Thinking about virtues might lead to a deeper understanding of our moral life and moral practice: In ancient Greece, moral philosophy started as a study of ethical and social excellence. But over the centuries, this enterprise has become trivial: The search for moral excellence degenerated into an analysis of the question how to prevent moral faults [...] 13

The various studies of virtues could be regarded as an attempt to halt this process of trivialization. But it is not necessary to demand a new start or even a revival. All we need for a good working virtue ethics already exists in nuce in the work of Moritz Schlick. Therefore, prospering in virtue ethics does not mean quitting analytic ethics, but going back to its beginnings and having a look at its roots.

NOTES

1. 2.

3.

4. 5.

Foot, Philippa, Virtues and Vices. Oxford: Basil Blackwell 1978, p. 1. Manfred Geier, “The Quest for Happiness: Traces of Ancient Life Wisdom within the Moral Philosophical Context of the Vienna Circle”, in: Herlinde Pauer-Studer (Ed.), Norms, Values, and Society, Vienna Circle Institute Yearbook. Dordrecht: Kluwer Academic Publishers. p. 13. I am referring to: Moritz Schlick, Problems of Ethics, translated by David Rynin; New York: Dover 1961,-and: Moritz Schlick, Lebensweisheit. Versuch einer Glückseligkeitslehre. Munich: C.H.Beck 1908. Moritz Schlick: Problems of Ethics, loc. cit. p. 102. Ibid., p. 80.

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6. 7.

8. 9. 10. 11. 12. 13.

Geier, “The Quest for Happiness: Traces of Ancient Life Wisdom within the Moral Philosophical Context of the Vienna Circle”, loc. cit., p. 17. Philippa Foot, “Rationality and Virtue”; in: Herlinde Pauer-Studer, H. (Ed.), Norms, Values and Society, Vienna Circle Institute Yearbook, Dordrecht: Kluwer Academic Publishers 1994, p. 210. Foot, Virtues and Vices, loc. cit., p. 8. Ibid., p. 2. John McDowell, “Two Sorts of Naturalism”; in: John McDowell, Mind, Value, and Reality, Cambridge (Mass.): Harvard University Press 1998, p. 170. Richard Hare, “Geach: Good and Evil”, in: Philippa Foot (Ed.), Theories of Ethics, Oxford: Oxford University Press 1967, p. 82. Dagmar Borchers, Die neue Tugendethik – Schritt zurück im Zorn? Paderborn: mentis 2001. Jaakko Hintikka in: Dagmar Borchers/Olaf Brill/Uwe Czaniera (Eds.), Einladung zum Denken. Ein Streifzug durch die Analytische Philosophic. Vienna: Hölder, Pichler, Tempski 1998.

Institut für Philosophie Universität Bayreuth 95445 Bayreuth Germany [email protected]

III.

HANS REICHENBACH

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CARSTEN KLEIN

COORDINATION AND CONVENTION IN HANS REICHENBACH’S PHILOSOPHY OF SPACE The concept of coordination (“Zuordnung”) was central to the writings of some of the early followers of Logical Empiricism. In his Allgemeine Erkenntnislehre (1918), Moritz Schlick characterized the process of cognition as a coordination of concepts with objects and of judgements with facts, while defining truth as uniqueness of coordination. Whereas Schlick’s conception was realistic in spirit, Hans Reichenbach used in his Relativitätstheorie und Erkenntnis apriori (1920) the concept of coordination in a framework that was still influenced by NeoKantianism. He emphasized the role of coordination with respect to the constitution of objects and introduced the idea of coordinative principles (“Zuordnungsprinzipien”) which are apriori in a relativized sense.1 Later, he abandoned the Kantian approach and moved on to a conventionalist epistemology, trying to separate factual and conventional kinds of coordination and calling the latter coordinative definitions (“Zuordnungsdefinitionen”). I would like to take a closer look at the concept of coordinative definition as it is employed in Reichenbach’s Philosophy of Space and Time (1928).2 I will argue that he employed two quite different concepts of coordinative definition here without distinguishing properly between them. The first one bears a strong similarity to the conception of definitional coordinations that can be found in Schlick’s Allgemeine Erkenntnislehre, regarding them as interpretation rules for the concepts of an axiomatic system. But without proper differentiation, Reichenbach used a different type of ‘coordinative definition’ in the broader sense of conventional elements of our world descriptions, despite their not being coordinations in a proper sense. I will try to show that the most prominent example of a so-called ‘coordinative definition’ in Reichenbach’s philosophy of space, the definition of congruence, is of such a kind. In his Philosophy of Space and Time, Reichenbach introduced the concept of coordination within the context of his distinction between mathematical and physical geometries. He took the idea that the application of a mathematical system to reality can be interpreted as a coordination of implicitly defined concepts with real objects from Moritz Schlick’s book General Theory of Knowledge (Allgemeine Erkenntnislehre, 1918).3 This way, a mathematical geometry is turned into an empirical theory. But not all coordinations can have a factual content and, hence, be true or false. Rather, there must be some coordinations that are definitional in nature, called coordinative definitions.4 109 F. Stadler (ed.), The Vienna Circle and Logical Empiricism: Re-evaluation and Future Perspectives, 109–120. © 2003 Kluwer Academic Publishers. Printed in the Netherlands.

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Reichenbach explains the idea of coordinative definitions by presenting a simple example. If a distance is to be measured, the unit of length has to be determined beforehand by definition. But that cannot be done by an ordinary conceptual definition, since such a definition does not say anything about the size of the unit. This can only be done by “reference to a physically given length” 5, i.e. by a coordinative definition. Before such “metrical coordinative definitions” are given, statements about distances do not have factual meaning. In this sense, Reichenbach calls them “logical presuppositions concerning measurements”.6 It is possible to express this insight in a different way: the adoption of a unit of measurement is not determined by facts, but is rather a matter of stipulation. Thus, coordinative definitions are examples of conventional elements in our world-description. In the given example, the coordinative definition is ostensive in nature, it can only be achieved by reference to a physical object: “‘that thing there’ is to correspond to such and such a concept”.7 According to Reichenbach, there is no difference in principle when there is an “insertion of some further concepts” between the concept to be defined and the real object. His example is the coordinative definition “a meter is the forty-millionth part of the circumference of the earth”. Here too we refer to a “physical length”, the circumference of the earth, even if the reference here is “rather remote” by means of the interposition of conceptual relations.8 And the situation is the same when we define the unit of length by reference to a certain wavelength. It is true that not the wavelength itself is observable but only certain phenomena like interference patterns, which are theoretically related to it. Nevertheless, the wavelength is “a piece of reality”, and thus it can play its part in a coordinative definition.9 That the unit of length must be defined before measurements are possible is not a very profound insight. But Reichenbach gives us this rather trivial example only in order to clarify the main characteristics of coordinative definitions. After this is done, he turns to the far more interesting case of the relation of congruence.10 But it will turn out that, contrary to Reichenbach, the definition of congruence is very different in nature compared to the definition of the unit of length. To determine whether two distances at different locations in space are congruent, we have to measure their respective lengths. The standard procedure is to carry a measuring rod from one place to the other and read off the respective numbers. By taking up insights of Hermann von Helmholtz, Reichenbach saw that the measuring procedure just described is subject to a hidden premise – namely, the presupposition that the length of the measuring rod did not change while transported. That this is by no means a matter of course becomes clear once we consider the question of determining such changes of length: it seems obvious that this can only be done by comparison with a different measuring rod. Now imagine a force that has the same effect on all objects regardless of their composition, and let this effect be of such a kind that the lengths of these objects change by the same factor while in transit from one point to another. It is easy to

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see that such a “universal force” could not be detected, since all relations of length would remain the same, and it is only such relations that can be measured. 11 Therefore, the assumption that such an effect does not arise cannot not be derived from observable facts.12 Reichenbach concludes: The problem does not concern a matter of cognition but of definition. There is no way of knowing whether a measuring rod retains its length when it is transported to another place; a statement of this kind can only be introduced by a definition.13

Thus the relation of congruence that holds between objects that are divided spatially is undetermined unless the concept of congruence has been fixed by definition. In this sense, the definition may again be called a “logical presupposition concerning measurements”. And since it is achieved by a coordination of the concept of congruence with “a real object”, here again we have a case of a coordinative definition.14 At least that is what Reichenbach tells us. But is this really a tenable point of view? When Reichenbach says that it is the function of coordinative definitions to give such statements that express the results of measurements an objective meaning, he seems to have a certain semantic model in mind. Coordinative definitions are regarded as semantic designation rules that determine the reference of geometrical concepts. And after their reference is fixed, they can be used in the context of a physical geometry to make assertions about the real world. This way of looking at coordinative definitions obviously follows the model of defining the unit of length: before the concept of a unit is given a reference, it cannot be used to make statements about the lengths of physical objects. But it would be a mistake to over-emphasize the similarity between this simple case and the definition of congruence. With respect to the coordination between concept and object, there is a principal difference between these two cases. It is plausible to consider the definition of the unit of length to be an ostensive definition. There is a physical object, the standard meter in Paris, that can be identified by an ostensive gesture as reference for the concept in question. And an interposition of other concepts does not change the way in which the coordination works. It does not matter whether one has a measuring rod or a pattern of interference: there is always an observable object that can be identified by an ostensive gesture, even if in the latter case the object of reference is not the observable pattern itself but the non-observable wavelength, which is connected to the observed phenomena by a simple conceptual relation. The case of the definition of congruence is completely different. Since it is a two-place-predicate, the coordinated entity can only be a relation, i.e. the relation which obtains between two spatially separated physical objects if their lengths turn out to be equal when measured by a transported rod. The extension of the congruence-predicate, then, is the class of pairs of congruent objects. This reading is supported by Reichenbach’s formulation that the concept ‘equality of length’ is coordinated to a “physical structure”.15 At first sight, this seems to be an acceptable view – why should we not regard relations as being real in the

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same sense as objects? 16 But since we can hardly point to a relation, the claim that coordinative definitions must be achieved “by reference” can no longer be maintained. To salvage the ostensive nature of coordinative definitions, we could say as an alternative that the objects taken to be congruent are themselves the entities coordinated with the concept. In Reichenbach’s text, a hint for this reading can be found as well: There is no way of knowing whether a measuring rod retains its length when it is transported to another place; a statement of this kind can only be introduced by a definition. For this purpose a coordinative definition is to be used, because two physical objects distant from each other are defined as equal in length. 17

The coordinative nature of the definition is substantiated by the fact that it determines physical objects which will be elements of the extension of the concept of congruence. But even if we regard the objects themselves as the “piece of reality” coordinated to the concept in question, the ostensive nature of the definition cannot be maintained. If we point to two objects and utter the words “these objects shall be equal in length”, we have not said anything at all about the congruence of all the other existing objects. The stipulated congruence of these two objects implies that a measuring rod does not change its length when transported from one to the other if the measurements give the same numbers. But it does not imply anything about universal changes of measuring rods between any other two objects. But there is another reading of Reichenbach’s definition of congruence which, at first glance, seems to avoid all these difficulties. Cannot the transported rod itself be the real object coordinated to the concept in question? 18 After all, the definition of congruence stipulates a certain behaviour of such rods when they are transported. And since it is sufficient to make such a stipulation with respect to one measuring rod only, it could simply amount to an utterance of the sentence “this rod does not change its length when being transported” together with an ostensive gesture. Is this not a definition by ostensive reference to a “piece of reality”? This conclusion, however, would be unjustified. In this definition, the ostensive reference is an accompanying element only. It serves as a means for identifying an object, whereas the actual definition is a statement about the behaviour of this object. This definition does not just consist in an ostensive gesture, accompanied by the utterance of the concept in question, as it is the case in the definition of the unit of length. In the latter case we just utter the words “unit of length”, pointing to the standard meter, but in order to define the concept of congruence we do not just point to a measuring rod and say “congruent”. It is not a definition by ostension, but with the help of an ostension. Whereas in the case of the unit of length the function of the ostension is to fix the reference of the concept by a kind of baptism, in the case of the definition of congruence the reference is fixed by a stipulative statement about the behaviour of the object identi-

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fied by the ostension. In order to make the definition, we have to point to the rod, but the concept defined does not refer to the rod but to a relation obtaining between certain pairs of objects. This fundamental difference is substantiated by the fact that an ostensive gesture is not an essential element of the definition of congruence but only a feature of a certain formulation. In the subsequent parts of his book, Reichenbach goes on to formulate the definition of congruence as a statement about the absence of universal forces.19 This is a definition of congruence because without universal forces, the change in the lengths of transported rods is no longer a matter of stipulation but an observable fact. Thus, statements about the congruence of spatially separated objects now have factual content, are true or false. The stipulative statement about the absence of universal forces still determines the extension of the congruence-predicate, but there is no longer a direct reference to a physical object. Hence, this formulation of the definition is not ostensive but discursive. It is because of this that one might claim that Reichenbach uses the concept of coordinative definition in two respects in his Philosophy of Space and Time: One the one hand, this concept is used for ostensive definitions in analogy to the definition of the unit, where something real gets coordinated to a concept by way of ostension. Typical for this kind of definition, which can be taken as a coordinative definition in the stricter sense, is the property that what we are dealing with are singular sentences which can be substituted in principle by the mere utterance of the word in question together with an ostensive gesture. On the other hand, there can be no doubt that the term ‘coordinative definition’ is used in a more general sense for definitions which determine the reference of a concept, even if this method of determination does not proceed in an ostensive but in a discursive way. Besides formulating the definition of congruence by way of stipulative elimination of all universal forces, this becomes clear especially with respect to Reichenbach’s claim that the specification of a certain physical geometry is a coordinative definition of congruence. For not only does it hold that, given a concept of congruence F, the physical geometry G is empirically determined in a unique way. Given a certain geometry G, the concept of congruence F is also no longer a matter of free choice but is determined by the results of observation. Reichenbach is of the opinion that this case is of the same kind as the coordinative definition of the unit of length by reference to the circumference of the earth. But while it may be possible (with a grain of salt) to treat the circumference as a physical object that can be identified by an ostensive gesture and one that is connected to the unit to be defined by an interposition of concepts, it is hardly possible to point to a geometry in any particular sense. The coordinative definition that is achieved by specifying a geometry is discursive, the reference to a physical object being nowhere necessary. Moreover, this second, discursive type of a coordinative definition which I shall call here a coordinative definition in the more general sense differs from ostensive definitions with respect to its logical form. Definitions of the first type

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are singular sentences and can also be expressed as a metalinguistic designation rule: “The unit length is the length of the standard meter in Paris” or “‘1m’ refers to the length of the standard meter in Paris” or “‘1m’ refers to this length over there” together with an ostensive gesture.20 Its only function is to supply the definiendum with a reference in order to use it for the formulation of physical statements. By contrast, coordinative definitions in the more general sense are universal statements like “rigid rods do not change their lengths when transported”, “there are no universal forces” or “the geometry of physical space is Euclidean”, sentences, that is, which make a general statement about a certain type of physical objects. It is clear that these statements cannot be (re)formulated as simple rules of designation of the type “‘x’ refers to y”, for what these sentences express is a law-like statement which is part of the theoretical description.21 It is by virtue of its completely different logical status that the definition of congruence plays an important role within the structure of the theory of physical space in the first place, even if it cannot be denied that it also plays a role in determining the extension of the predicate. For as we have seen, different coordinative definitions lead to different geometries, and even our “physics of everyday life” would have to undergo radical changes if we were to assume that objects change their lengths when transported. Thus the concept of congruence plays an important role within the theoretical description of our world. Similar things cannot be said with respect to the concept of the unit of length. Changing the definition of unit has no effect whatsoever on the structure of the theory: although it would lead to a change of all metrical statements by a certain factor, the formulation of theoretical laws would not be effected.22 To use an expression of Carl Gustav Hempel, one could say that the concept of congruence has considerably more systematic import than the concept of the unit of length.23 This is exactly why the freedom with respect to determining the relation of congruence is so interesting: it reflects certain structural properties of the theoretical description of physical space. And as Reichenbach has correctly recognized,24 the systematic import of the concept of congruence is even considerably higher. For the concept of the equality of length plays a role in nearly all physical laws, since it occurs in almost every physical quantity of derivative nature. Thus, changing the definition of congruence would not only have an effect on physical geometry but on nearly the whole spectrum of physical theories, while changing the concept of the unit of length would only result in a new scaling of metrical statements. This justifies us in taking the concept of congruence as a law cluster concept; that is, as a concept which occurs in a large number of natural laws and the meaning of which is given by these laws. And it is exactly this property that renders the conventionality of congruence an interesting question. That the reference of a concept like ‘unit of length’ must first be determined by a definition before it can be used to formulate results of measurement is of no significance. That a law-like statement about the behaviour of rigid bodies or the existence of universal forces must be made in order to determine

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the reference of ‘congruent’, by contrast, is by no means a matter of course but provides an interesting insight into the structure of physical theories. This result, however, should rather be formulated within Reichenbach’s terminology of equivalent descriptions: The equivalent descriptions which result from changing the standards of length differ only with respect to a constant factor in the numerical values of their metric statements. That the descriptions are equivalent and that the choice between them is of a conventional nature is easy to see; everybody will agree that this conventionality is hardly of any specific epistemological significance. By contrast, the descriptions which result from changing the definition of congruence differ with respect to the premises about the geometry of space and the occurrence of universal forces. That these descriptions are equally admissible and empirically indistinguishable is a significant property of the theory in question. If we consider the complete description G + F, the nature of the definition of congruence becomes clear: It is a stipulative determination of the conventional element of this description. And it is because one part of the description, the Fcomponent, refers to the relation of congruence that the specification of the conventional element results in a coordination. This holds even if it is formulated as a statement about the geometry G. Hence, it is not completely wrong when Reichenbach states that the specification of a geometry G is just a different way of giving a coordinative definition of congruence. But it is misleading, because it seems to imply the view that conventionality is a property not of the whole description but of particular statements within the description, whereas other statements are factual in nature. As a consequence, there would be a definite and unique separation of conventional and factual elements in our description of physical space. In fact, this seems to have been Reichenbach’s position in 1928. But it is difficult to follow him on this point. Since there is a symmetry in the two methods of determining the conventional element inherent in the description G + F, viz. the specification of F or the specification of G, there is no reason to ascribe the conventionality to F alone in both cases. Reichenbach points out correctly that a statement about the geometry G has no factual meaning unless the concept of congruence is determined. But the same holds the other way round: a statement about universal changes of transported rods has no factual meaning unless the geometry G is specified. Because of this symmetry, calling the specification of G a definition of congruence seems unjustified. As Quine emphasized a couple of years later, we should rather adopt the view that conventionality and factuality are spread out over the whole description.25 Interestingly enough, this is exactly the position Reichenbach held in 1923: We have a certain freedom in employing definitions and facts. It is only when a definition is given in one place that another assertion becomes an assertion of fact; conversely, the second may be regarded as a definition, which makes the first into an assertion of fact.26

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If this is true, then conventionality can only be ascribed to the whole description, and the existence of a conventional element is shown by the fact that there are alternative descriptions that are logically incompatible but equally true. Why did Reichenbach change his position between 1923 and 1928? I think that one of the reasons is to be found in his aim of arguing against the geometrical relativism he ascribed to Poincaré. He takes the latter to be of the opinion that “it is impossible to make an objective statement about the geometry of physical space, and that we are dealing with subjective arbitrariness only”, which for Reichenbach amounts to saying that the concept of the geometry of real space itself is “meaningless”.27 By contrast, Reichenbach wants to hold on to the view that the concept of a geometry of physical space is meaningful and that statements about this geometry have objective factual content. In order to defend this position, he feels compelled to ascribe the definitional character solely to the relation of congruence, thus preserving the purely factual character of the geometry: Although the statement about the geometry is based upon certain arbitrary definitions, the statement itself does not become arbitrary: once the definitions have been formulated, it is determined through objective reality alone which is the actual geometry. ... it is the significance of coordinative definitions to lend an objective meaning to physical measurements.28

This argument, however, does not succeed. If the statement of the geometry is based on arbitrary definitions, then it is itself arbitrary. For it is possible to obtain any geometry by choosing an appropriate definition of congruence. Reichenbach’s real achievement in his efforts to avoid Poincaré’s scepticism is the insight that, though not G alone, the combination of G and F does have factual content. Hence, not the physical geometry alone is rescued from arbitrariness by Reichenbach’s argument, but the combination of geometry and the concept of congruence. But according to this reading, there is no reason to ascribe conventionality to the specification of congruence alone. The whole description G + F is conventional insofar as there are different but equally admissible descriptions G’ + F’. And it is factual because the class of admissible descriptions is restricted by physical reality: if one of the two components is given, the choice of the other component is a matter of fact. The decision which component, G or F, is specified by stipulation is itself arbitrary. There is no unique separation of factual and conventional components.29 But there seems to be another reason for Reichenbach’s view that conventionality can be ascribed to the specification of congruence in an absolute way: his belief in the alleged similarity of the two kinds of coordinative definitions I have tried to keep apart. Reichenbach seems to think that the connection between the concept of congruence and the geometrical concepts is of the same kind as the connection between the concept ‘unit of length’ with the concept ‘forty million times the unit of length’. According to Reichenbach, the specification of

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the physical geometry is a definition of congruence in the same sense in which the specification of the physical object coordinated to ‘forty million times the unit of length’ is a definition of the unit of length.30 But this analogy is not as farreaching as Reichenbach thinks. There is a very simple derivative relation between the concepts ‘forty million times the unit of length’ and ‘unit of length’. It makes good sense to call the one concept primitive and the other derivative, and it seems therefore natural to read the specification of the derivative concept as a definition of the primitive concept from which it was derived. But the relation between the geometrical concepts (e.g., ‘straight line’) and the concept of congruence is far more complicated, and we have no good reason to insist that ‘congruent’ is primitive and ‘straight line’ is derivative. Thus, it is not at all clear why we should read the specification of the geometry as a definition of congruence. That Reichenbach held a different and, I think, more correct view in his 1923 paper may be explained by the influence of Schlick, which is more prominent in this paper than in The Philosophy of Space and Time. The view that the conventionality is spread over the whole system of coordinations and cannot be located in some particular coordinations in an absolute sense is inherent in Schlick’s original conception of the coordination of a system of implicitly defined concepts with real objects. Why should any of these concepts be special in the sense that the procedure of coordination must begin with this particular concept, making its coordination definitional and all the others factual? If we consider Reichenbach’s argument for the necessity of coordinative definitions: “... certain preliminary coordinations must be determined before the method of coordination can be carried through any further; these first coordinations are therefore definitions ...”31, we can see no reason why one particular coordination has to be the first and, therefore, definitional one. So even if we conceded, for the sake of argument, that the definition of congruence would work in the way Reichenbach says, viz. by a simple coordination with a physical object, there is no reason why the status of definition should be ascribed to this coordination in an absolute way. To conclude: I hope to have shown that the conception of coordinative definition in Hans Reichenbach’s philosophy of geometry is burdened by the fact that it stretches this concept too far. There are conventional stipulations in a description of physical space that are not coordinative definitions in the strict sense, although they do indeed specify the extension of the concept in question. One of these kinds of definitions is the definition of congruence, erroneously presented by Reichenbach as a paradigmatic example of coordinative definitions. Furthermore, the alleged similarity of the definition of congruence to coordinative definitions proper may have been one reason why Reichenbach changed his position concerning the localizability of conventional elements in our descriptions of the physical world. I want to suggest that we should rather describe the situation from the point of view of the whole description: Every description has conven-

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tional elements that have to be specified by stipulations. However, only some of these stipulations are coordinative definitions in the strict sense, and these are not the really interesting ones.

NOTES

1.

For Reichenbach’s relativized notion of the a priori cf. Michael Friedman, “Geometry, Convention and the Relativized A Priori: Reichenbach, Schlick, and Carnap”, in: Wesley Salmon, Gereon Wolters (Ed.), Logic, Language and the Structure of Scientific Theories, Proceedings of the Carnap-Reichenbach Centennial Konstanz 1991. Pittsburgh: Pittsburgh University Press 1994, pp. 21-34. 2. Hans Reichenbach, Philosophie der Raum-Zeit-Lehre. Berlin/Leipzig: Walter de Gruyter 1928. All further references will be made to the English translation: Philosophy of Space and Time, trans. Maria Reichenbach and John Freund. New York: Dover Publications 1958. 3. Moritz Schlick, Allgemeine Erkenntnislehre. Berlin: Springer 1918, 2 1925, §§5-10. Translated as General Theory of Knowledge, trans. A.E. Blumberg. New York: Springer 1974. An explicit reference to Schlick can be found in the Philosophy of Space and Time, loc.cil., on p. 14, fn. 1. As early as 1923, in his paper “Ziele und Wege der physikalischen Erkenntnis”, Reichenbach had adopted some essential features of Schlick’s epistemology: the idea that knowledge can be understood as coordination of concepts with objects, the idea that truth is uniqueness of coordination and the interpretation of concepts as signs. (M. Thirring (Ed.), Allgemeine Grundlagen der Physik, vol. 4 of Handbuch der Physik, H.Geiger und Karl Scheel (Eds.). Berlin: Springer 1929, pp. 1-80. All further references will be made to the English translation: “The Aims and Methods of Physical Knowledge”, in: Maria Reichenbach, Robert S.Cohen (Eds.), Hans Reichenbach: Selected Writings, vol. 2. Dordrecht: Reidel 1978. 4. Reichenbach, The Philosophy of Space and Time, loc. cit., p. 14. The concept of coordinative definition is already introduced in “The Aims and Methods of Physical Knowledge”, loc. cit., p. 161: “The coordination of concepts with objects that is carried out in natural science is not always such that it yields knowledge. While the matter of which concept should be coordinated is, in general, established as a result of research, the coordination may in particular instances consist of an arbitrary stipulation. These cases constitute physical definition. Their mark of distinction is that, instead of coordinating a concept with a particular combination of other concepts, as done in definitions of concepts, they coordinate a concept with an existing object. ... As the coordination between object and concept is peculiar to this type of definition, we shall refer to it as coordinative definition.” 5. Reichenbach, The Philosophy of Space and Time, loc. cit., p. 15. 6. Ibid., p. 146. 7. Reichenbach, “Aims and Methods of Physical Knowledge”, loc. cit., p. 33. 8. Reichenbach, The Philosophy of Space and Time, loc. cit., pp. 15, 128. 9. Ibid., p.15. 10. Ibid., pp. 15-17. 11. Reichenbach’s notion of a “universal force” is rather obscure. It seems highly questionable to classify a quantity as a force when it has no physical cause, cannot be tested empirically for principal reasons, and can be ‘defined away’ by choosing a different definition of congruence. Perhaps one should use the notion of universal effects instead, leaving it an open question whether there are in fact any forces causing these effects. A coherent interpretation of the notion of universal force is made even more diffcult by Reichenbach’s claim that gravitation is an example of such a force (ibid., p. 256), although gravitational forces are, without question, empirically detectable. Lionel Shapiro claims to have identified no less than four different notions of universal force in the Philosophy of Space and Time (Lionel Shapiro, “ ‘Coordinative Definition’ and Reichenbach’s Semantic Framework: a Reassessment“, in: Erkenntnis 41, 1994, pp. 287-323). And according to Adolf Grünbaum, the notion of universal force has to be under-

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13. 14. 15. 16. 17.

18.

19. 20.

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24. 25.

26. 27.

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stood in a metaphorical way, with the consequence that the definition of congruence can be formulated without saying anything as to the existence or non-existence of universal forces (Adolf Grünbaum, Philosophical Problems of Space and Time (Second, enlarged edition) (= Boston Studies in the Philosophy of Science, Vol. 12). Dordrecht/Boston: Reidel 1973, pp. 8197). (What Grünbaum has in mind is Carnap’s definition of congruence as put forward in his dissertation Der Raum.) An appeal to different methods of metric measurement does not invalidate the argument since the universal force can always be constructed in such a way that it effects the results of all kinds of measurement in the same way. Reichenbach, The Philosophy of Space and Time, loc. cit., p. 16. Ibid., p. 16. Ibid., p. 16. In “The Aims and Methods of Physical Knowledge” Reichenbach explicitly argues for accepting relations as something real in the same sense as objects (loc.cit., pp. 149-150). Reichenbach, The Philosophy of Space and Time, loc. cit., p. 16. “Physical objects” is an incorrect translation of “wirkliche Dinge” (“real objects”) in the German original (Philosophie der Raum-Zeit-Lehre, loc. cit., p. 25). This seems to be Reichenbach’s view in 1949. In his contribution to the Einstein Schilppvolume, he writes: “For instance, the concept ‘equal length’ is defined by reference to a physical object, a solid rod, whose transport lays down equal distances.” (“The Philosophical Significance of the Theory of Relativity”, in: Paul Arthur Schilpp (Ed.), Albert Einstein: Philosopher – Scientist. La Salle, Ill.: Open Court 1949, p. 294.) “It seems that the coordinative definition F = 0 is simpler ...” (Reichenbach, The Philosophy of Space and Time, loc. cit., p. 34). Coordinative definitions of this kind are similar to Carnap’s designation rules for semantic systems. Their task is to supply the descriptive constants of a theory with a physical interpretation. In the case of individual constants, they are of the form “‘mond’ designates the moon”. (Rudolf Carnap, Foundations of Logic and Mathematics (= International Encyclopedia of Unified Science, Vol. I, No. 3). Chicago: University of Chicago Press 1939, p.9.) The objection that a definition cannot be a law of nature is not cogent. I will argue at some later point that there is no unique distinction between conventional definitions and factual assertions. Hence, the statement “rigid rods do not change their lengths during transport” can be regarded as a law of nature, as can the statement “the sum of the interior angles of every physically realized triangle is 180°”. This is only correct if the possibility of a definition of the unit of length by a non-rigid body is not taken into account. If one used a rubber band as a standard of length, every length would depend on the momentary state of extension of the rubber band. This would result in an immense complication of physical laws. The possibility of using a non-rigid body, however, does also exist in the case of the definition of congruence. But in the latter case, even after the exclusion of all non-rigid bodies, there is still room for non-trivial variations, which is not true for the definition of the unit of length. According to Hempel, concepts have systematic import if they open up the possibility for formulating explanatory and predicting principles in the form of general laws or theories. (Carl Gustav Hempel, Fundamentals of Concept Formation in Empirical Sciences (= International Encyclopedia of Unified Science, Vol. II, No. 9). Chicago: University of Chicago Press 1952, p. 46. Reichenbach, Philosophy of Space and Time, loc. cit., pp. 23 f. Willard Van Orman Quine, “Truth by Convention”, in: The Ways of Paradox and other Essays, Cambridge, MA: Harvard University Press 21976, pp. 77-106. (First published in: O.H.Lee (Ed.), Philosophical Essays for A.N. Whitehead. New York: Longmans 1936). Reichenbach, “The Aims and Methods of Physical Knowledge”, loc. cit., p. 163. Reichenbach, Philosophy of Space and Time, loc. cit., pp. 36-37. It has been pointed out several times that Reichenbach’s interpretation does not do justice to Poincarés intentions. For a prominent example, see Grünbaum, op. cit., pp. 127-131. Reichenbach, Philosophy of Space and Time, loc. cit., p. 37.

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29. For a more detailed account of Reichenbach’s conception of equivalent descriptions and the role it plays in the refutation of Poincaré’s geometrical relativism, cf. Carsten Klein, “Conventionalism and Realism in Hans Reichenbach’s Philosophy of Geometry”, in: International Studies in the Philosophy of Science 15, 3, 2001, pp. 243-251. 30. Reichenbach, The Philosophy of Space and Time, loc. cit., p. 34. 31. Ibid., p. 14.

Philosophisches Seminar Universität Bonn Am Hof 1 D-53 113 Bonn Germany [email protected]

ROBERT RYNASIEWICZ

REICHENBACH’S OF S IMULTANEITY IN HISTORICAL AND PHILOSOPHICAL PERSPECTIVE § 1. It is well-known that in the special theory of relativity the simultaneity of distant events is frame-relative: two events that are simultaneous according to the standard Einstein criterion as applied in one inertial frame are not simultaneous according to the same criterion applied in a relatively moving inertial frame. Not so well known is whether, given a fixed inertial frame, there is a fact of the matter whether a pair of distant events are really simultaneous relative to that frame. Einstein thought not. Reichenbach, at least according to the lore philosophers of science are taught, thought not. And up until roughly a quarter century ago, the thesis that frame-relative simultaneity is a matter of convention was the prevailing view. Not any more. There is now a widely espoused anti-conventionalist view inspired by a result published by David Malament in 1977. The standard Einstein criterion is the only candidate for a frame-relative simultaneity criterion definable from the causal structure of Minkowski space-time.1 Hence, according to the neo-anti-conventionalist, if frame-relative simultaneity is conventional, then it is conventional only in some minimal and not very exciting or robust sense. However, claims as to what is exiting or robust, if they are to be meaningful, must be claims about comparisons. I want to take this opportunity to compare and contrast two possible conventionalist positions on frame-relative simultaneity, one of them decidedly more robust than the other. The more robust of these is implicitly suggested by Einstein’s 1905 paper.2 The other, I shall suggest, is the most plausible reading of Reichenbach’s conventionalism in connection with his celebrated of distant simultaneity. This will give me the chance not only to engage in a bit of Reichenbach scholarship, but also to impress upon the neo-anti-conventionalist camp that there is more than a minimal conventionality thesis to take into account. § 2. In order to set up the conventionalist position suggested in Einstein’s original 1905 paper, recall the procedure followed there. One establishes the fixed points of an inertial frame (presumably by testing for inertial forces), lays out a spatial coordinate grid using rigid rods and the laws of Euclidean geometry, and institutes a natural clock at each fixed point. There remains the further task of synchronizing these clocks if one is to be able to describe trajectories as a function of a system-wide time. Without such one cannot assign a three-velocity tan121 F. Stadler (ed.), The Vienna Circle and Logical Empiricism: Re-evaluation and Future Perspectives, 121–129. © 2003 Kluwer Academic Publishers. Printed in the Netherlands.

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gent vector to a point of the trajectory. Thus, one simply stipulates that the time it takes for light to propagate from point A to point B of the frame equals the time of propagation from B to A. From this follows the familiar Einstein synchronization criterion, that a natural clock at A is in synchrony with natural clock at B if

where is the time at A of light emission from A, the time at B of its reflection at B, and the time at A of its return to A. The derivation of the Lorentz transformations proceeds directly from this (and the validity of the light postulate) by assuming that the “moving” frame uses the same synchronization criterion from its point of view for co-moving clocks. In short, the procedure is this. Adopt a synchronization procedure consistent with the empirically testable fact that the average round trip speed of light in any frame is a fixed constant. Then apply the Principle of Relativity to that procedure in order to derive the coordinate transformations to a relatively moving frame. But if, as Einstein insists, the one-way speed of light assumption on which clock synchronization is based is really just a matter of stipulation, what happens if one replaces it with an alternative stipulation compatible with the constancy of round trip average speed, and then applies the Principle of Relativity to the induced non-standard synchronization procedure? Does this yield a consistent alternative 3+1-dimensional formulation of special relativity? § 3. With this question in mind, I began to scour the Reichenbach archives for calculations to see if Reichenbach had indeed thought along these lines in the course of formulating his famous of clock synchronization,

from which, the standard Einstein criterion falls out as the special case In 1921 Reichenbach published a preliminary sketch of his plan to develop an axiomatization of relativity theory in such a way that it would have the virtue of separating out the factual from the conventional components of the theory by instituting only directly testable propositions as axioms and introducing the conventional components as “coordinative” definitions. This “Bericht über eine Axiomatik der Einsteinschen Raum-Zeit-Lehre” introduces only the standard Einstein synchronization criterion as a coordinative definition [Definition 5].3 The first appears in print only in 1924 as Definition 2 of the extensively reworked and vastly expanded culmination of that project, Axiomatik der relativistischen Raum-Zeit-Lehre.4 Moreover, its introduction there appears to have been an eleventh-hour addition. There are two complete copies of a mono-

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graph-length draft, suggesting that Reichenbach thought it ready, or nearly ready for press, but in which still only the standard Einstein definition appears. Only amongst scraps of loose handwritten pages did I find a precursor (see fig. 1) to the in the published version.5

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The portion of typed text is the whole of Definition 5 cut out from a reprint of the “Bericht” (see fig. 2) and the emendations make it accord verbatim with Definition 2 of the Axiomatik. The context of its introduction also accords, although not verbatim, with the published version – the middle of a proof of Proposition 6, which, in order to grasp its upshot, requires some exposition of Reichenbach’s overall strategy. § 4. When Hermann Weyl reviewed Reichenbach’s Axiomatik,6 he confessed that he found it “less than satisfactory: overly tedious and too obscure” [wenig befriedigend, zu umständlich und zu undurchsichtig].7 This, Reichenbach later complained, was based on a gross misunderstanding.8 In the review, Weyl had characterized the Axiomatik as, in the main, not a philosophical, but a purely mathematical investigation, and had registered the above assessment “from a mathematical point of view” [nach mathematischen Gesichtpunkten].9 Reichenbach was dismayed that someone of Weyl’s rank could have missed his main thrust. Weyl, though, may have well have appreciated Reichenbach’s intentions more fully than Reichenbach realized. The execution of the Axiomatik is in fact more easily grasped from a mathematical than a philosophical point of view. Reichenbach begins with the class of all possible world-lines in space-time and then attempts to find conditions, involving only the conformal structure of the space-time, sufficient to select out the distinguished subsets which correspond to inertial frames. Using only the behavior of light rays, he defines separate temporal and spatial metrics for individual frames, which he calls the “light-geometry” [Lichtgeometrie], and then derives the Lorentz transformations as the isometry boosts for the light-geometry. (A defect of this procedure, and one certainly not lost on Weyl, is that the class of inertial frames cannot be singled out in this fashion, but only a wider class of frames related by conformal transformations. Reichenbach had sensed the problem, but probably at a stage too late for him to make major revisions. Only in a later section does he alert the reader to the difficulty, and then only in an attempt to mitigate the extent to which it might be viewed as undermining his program.) So far no mention is made of rigid rods and material clocks. These notions are introduced only after the development of the light-geometry, at which point Reichenbach sets out a series of “matter axioms” which collectively assert that these material structures behave in accordance with the light-geometry and thus the Lorentz transformations. The upshot of the entire work is that, apart from the prohibition on super-luminal causal propagation, it is only these latter assertions that separate relativity theory from classical space-time physics. The physical axioms governing the behavior of light do not depend on a principle of relative motion and are consistent with both the (relativistic) light-geometry and the geometry [or rather, kinematics] of classical optics. As Reichenbach explains:

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It is remarkable that the Lorentz transformation, conceived in light-geometrical terms, does not contain a new axiom but depends solely on definitions and axioms of the single system. With respect to light, there does not exist a special axiom of uniform translation. Our derivation of the Lorentz transformation via the Galilean transformation has shown that it is merely a reorganization of the relations of uniformly moving systems contained in the Galilean transformation into a new metrical determination. Physically new is Einstein’s idea that material structures do not adjust to the Galilean metrical determination but to the light-geometrical one.10

Faintly visible under this thumbnail sketch, in the notion of the “adjustment” [Einstellung] of material structures to the light-geometry, is the specter of Weyl – or more precisely, that of Weyl’s generalization of Riemannian geometry in his attempted unified field theory – which provides a clue as to why Reichenbach pursued the strategy of developing a light-geometry in no way dependent on the use of material metrical standards. Noteworthy is the fact that the first two matter axioms are formulated in tune with the conceptual framework of gauge field theory, asserting the path independence of the behavior of material rods and clocks. Indeed, Reichenbach mentions in a footnote in the Introduction11 that a hint that the construction of a light-geometry is possible occurs in the Appendix to the fourth edition of Weyl’s Raum-Zeit-Materie.12 The notion of “adjustment” [Einstellung] is also taken over directly from Weyl. In his later reply to Weyl’s review of the Axiomatik, though, Reichenbach clarifies that he does not take this to be a concept with explanatory force so much as a shorthand for the problem of finding a fundamental theory of matter. It is worth mentioning that Reichenbach there indicates that he regards the matter axioms to hold only as a “first approximation” (even to the extent that they are locally valid according to the general theory of relativity) and even cites the positive result of Dayton C. Miller’s repetition of the Michelson-Morley experiment as potential evidence (assuming the result is not spurious, as it turned out to be). In contrast to his attitude toward the matter axioms, Reichenbach regards the light axioms as completely secure and describes the light-geometry as the most natural description (from the point of view of descriptive simplicity) of the intrinsic geometry of the electromagnetic field. § 5. What role, then, does Reichenbach’s of simultaneity play in the construction of the light-geometry? The sad answer is, disappointingly little, at least from a formal point of view. It is introduced early on, primarily in order to show how little needs to be assumed in order to introduce a global time function in conformity with causality constraints. The method is to choose a central “clock” in the sense of an arbitrarily parameterized world line and then to export this parameterization to every other world line in space-time via for an arbitrary, but fixed value of Reichenbach quickly specializes to in order to define a time function for each “stationary spatial” frame [stationäres räumliches Koordinatensystem]. The class of inertial frames is later extracted from the class of all “stationary spatial” frames.

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There is thus no inkling of the possibility of an invariant non-standard synchronization criterion for inertial frames. Rather, it is more likely that Reichenbach believed that the restriction to is in fact necessary for selecting the inertial frames in the course of constructing the light-geometry. This surmise is reinforced by a comment four years later in his Philosophie der RaumZeit-Lehre,13 that Einstein’s definition is in fact essential for the special theory of relativity: “Diese Definition ist zwar fuer die spezielle Relativitaetstheorie wesentlich ...”.14 He does go on to say that, nonetheless, this definition is not epistemologically necessary – any choice between zero and one for the parameter wouldwork and could not be said to be false. But work in what regard? In the Axiomatic, after Reichenbach introduces the generalized and puts it to limited technical use, there follows what might appropriately be called a philosophical scholium, though not labeled as such. It begins by characterizing the light axioms so far introduced as the “topological axioms of time order” and proceeds to call attention to the “topological problem of simultaneity”: in essence, does causal structure pick out at a given space-time point a unique hypersurface as causally neither prior nor posterior, or, as is the case if there is a limiting causal process, does there exist an indeterminate region corresponding to an entire family of distinct hypersurfaces? In the former case it is appropriate to speak of absolute simultaneity; in the latter, simultaneity is “relative” insofar as the definition of simultaneity is not uniquely determined by causal structure. The word “relative” here, however, does mean “specific to the special theory of relativity.” In the Introduction to the Axiomatic, Reichenbach carefully distinguishes between what he calls the epistemological and the physical relativity of simultaneity. The former refers merely to the underdetermination by causal structure. The latter is specific to Einstein’s theories of special and general relativity. It says in the special theory that a particular definition of simultaneity for uniformly moving systems gives rise to the complete equivalence of all measurement procedures and in consequence the laws of nature have the same form for all such systems. [Sie besagt in der speziellen Theorie, dass bei einer gewissen Definition der Gleichzeitigkeit (Definition 8) für gleichförmig bewegte Systeme völlige Gleichartigkeit aller Massverhältnisse entsteht und die Naturgesetze dann für solche Systeme die gleiche Form haben.] 15

To summarize in light of the results achieved in the Axiomatik: The epistemological relativity of simultaneity refers only to the fact that numerous distinct light-geometries (e.g., Galilean vs. Lorentzian) are consistent with the light axioms. The physical relativity of simultaneity speaks to the consequences of the further imposition of the matter axioms, to the effect that the standard practices of measurement using material rods and clocks agree with the choice of and the resulting Lorentzian geometry. Thus, as far as the Axiomatik is concerned, any adoption of a non-standard simultaneity criterion would necessitate

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the adoption of a different and highly irregular set of matter axioms appealing to “compensatory” factors and the like. As for the position in his Philosophie der Raum-Zeit-Lehre, Reichenbach sends no signal that he now intends the to pertain to any thesis bolder than the epistemological relativity of simultaneity. The comment that “if the special theory of relativity prefers the ... definition [that] sets equal to ½, it does so on the ground that this definition leads to simpler relations” 16 need not be construed to indicate anything more than a belief that other choices would necessitate the adoption of a different set of more complicated matter axioms. It is true that, in contrast to the Axiomatik, he explicitly mentions directionally dependent choices of but these are in connection with the price of adopting a classical (Galilean) light-geometry.17 The only portion of text that even remotely suggests otherwise reads: It was believed that the coupling of the space and time axes supplied by the Lorentz transformation, according to which every choice of the time axis determines a corresponding space axis as the conjugate diameter, signifies a more fundamental junction of space and time. This coupling, however, is relatively unimportant because it is based on an arbitrary additional requirement, introduced only for descriptive simplicity, for which there is actually no epistemological need.18

But the passage goes on: The mistake committed here is the one pointed out on page 146; it springs from the erroneous conception that there is a relation between the relativity of simultaneity and the relativity of motion.19 And indeed, if one goes back to consult page 146,20 it is clear that what Reichenbach means is that the epistemological relativity of simultaneity “has nothing to do with the relativity of motion. It rests solely on the existence of a finite limiting velocity for causal propagation.”21 § 6. What I have argued is that Reichenbach nowhere suggests the possibility of using a non-standard simultaneity criterion in conjunction with the principle of relativity. Such a criterion would have the following properties. It would result in the same light-geometry as the standard Einstein criterion in the sense that it would yield the same temporal and spatial measures as the standard within each inertial frame. Only the Lorentz transformations would need to be replaced by a conjugate representation of the same group. But each of the matter axioms would remain satisfied without revision, since these in fact do not explicitly involve the Lorentz transformations. I further suggest that Reichenbach believed that this could not be done. Many a reader may wonder whether indeed it can. Rather than formulating such in terms of directly, I’ll simply state a one-way speed of light rule that suffices. Using spherical coordinates, let be the angle from the azimuth. Then stipulate that the speed of light V in the direction satisfies the condition:

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where c is the usual average round-trip speed of light and a is an arbitrary scalar less than c. As an exercise, one can verify that this satisfies the requirement of constancy of average round-trip, derive the corresponding conjugate representation of the Lorentz transformations, and develop a complete, non-standard 3+1dimensional formulation of special relativity. Moreover, it is not too difficult to show that the most general category of frame invariant non-standard simultaneity criteria is given by letting the magnitude of the cosine term in the denominator represent the projection of an arbitrary irrotational vector field (of norm less than c) onto the azimuth. 22 The intent here is not to denigrate Reichenbach for failing to realize a possibility that in fact exists. Rather it is to come to a clear understanding as to the range of possibilities that he in fact did recognize. Indeed, it is to his credit to have articulated the distinction between what he called the epistemological and the physical relativity of simultaneity. For that distinction, just slightly re-articulated, serves to demarcate two distinct levels of convention potentially inherent in the adoption of a simultaneity criterion. The epistemological level concerns the degree of fixity dictated by causal structure alone, entirely apart from constraints deriving from the standard deployment of material measuring rods and clocks for the determination of spatial distances and proper-time lapses, respectively. The “physical” level corresponds to the degree of freedom that remains with these latter constraints in place. Much of the debate on the conventionality of simultaneity has tended to suffer from not tracking carefully enough the difference between these two levels. Acknowledgements. I would like to thank W. Gerald Heverly and his staff at the Archives of Scientific Philosophy, University of Pittsburgh Libraries for their kind hospitality and assistance.

NOTES 1. 2. 3. 4.

David Malament, “Causal Theories of Time and the Conventionality of Simultaneity”, in: Noûs 11, 1977, pp. 293-300. Albert Einstein, “Zur Elektrodynamik bewegter Körper”, in: Annalen der Physik 17, 1905, pp. 891-921. Hans Reichenbach, “Bericht über eine Axiomatik der Einsteinschen Raum-Zeit-Lehre”, in: Physikalische Zeitschrift XXII, 1921, pp. 683-687. Hans Reichenbach, Axiomatik der relativistischen Raum-Zeit-Lehre. Braunschweig: Friedrich Vieweg & Sohn 1924. Definition 2 appears on p. 26. This corresponds to p. 35 of Maria

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6. 7. 8. 9. 10. 11. 12. 13. 14. 15.

16. 17.

18. 19. 20. 21. 22.

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Reichenbach’s translation, Axiomatization of the Theory of Relativity. Berkeley: University of California Press 1969. Document HR-024-15-02 of the Hans Reichenbaoh Collection, Archives of Scientific Philosophy and General Manuscripts. Reproduced by permission of the University of Pittsburgh. All rights reserved. In: Deutsche Literaturzeitung 30, 1924, pp. 2122-2128. Ibid., p. 2128 Hans Reichenbach, “Über die physikalischen Konsequenzen der relativistischen Axiomatik”, in: Zeitschrift für Physik 34, 1925, pp. 32-48. See especially Section II, pp. 37-38. Ibid. Reichenbach, Axiomatik der relativistischen Raum-Zeit-Lehre, loc. cit., p. 58. I have used here Maria Reichenbach’s translation, loc. cit., p. 76. Emphasis is in the original. Ibid., p.10. Berlin, Springer 1921. There are in fact two appendices. Reichenbach obviously intends to refer to Appendix I. Berlin: Walter de Gruyter 1928. Translation by Maria Reichenbach, The Philosophy of Space and Time. New York: Dover 1957. Ibid., p. 151. Emphasis mine. Reichenbach, Axiomatik der relativistischen Raum-Zeit-Lehre, loc. cit., p. 8. The translation is mine. Maria Reichenbach’s translation, loc. cit., p. 11, does not adequately convey the intent of the passage. Maria Reichenbach’s translation, loc. cit. p. 127. See, for example, p. 204 of Philosophie der Raum-Zeit-Lehre, loc. cit. (p. 176 of Maria Reichenbach’s translation, loc. cit.) Note that the example worked at length in §26 is an explicit illustration of this. Maria Reichenbach’s translation, loc, cit., p. 189. Ibid. This pagination refers to Maria Reichenbach’s translation, loc. cit. In the original it is p. 172. Maria Reichenbach’s translation, loc. cit., p. 146. It has recently come to my attention that this result is reported in R. Anderson, I. Vetharaniam, and G. E. Stedman, “Conventionality of Synchronization, Gauge Dependence and Test Theories of Relativity”, in: Physics Reports 295, 1998, pp. 93-180, and can be traced back to section 9.16 of C. Møller, The Theory of Relativity, second edition. Oxford: Clarendon Press, 1972.

Department of Philosophy Johns Hopkins University Baltimore, MD 21218 U.S.A. [email protected]

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OTHER PROPONENTS AND PERIPHERY

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JUHA MANNINEN

TOWARDS A PHYSICALISTIC ATTITUDE In a footnote to his paper ‘Experience, Cognition and Metaphysics’ (1926), Moritz Schlick mentioned the two philosophers he thought to be the most promising to his field, Rudolf Carnap and Ludwig Wittgenstein. According to Schlick, all knowledge had to be communicable and expressed through various kinds of symbols. But everything that had to do with the qualitative contents of our experience remained private: “... the content of the acquaintance cannot be con1 veyed by any knowledge; it is not expressible or communicable.” Schlick emphasized: This account is absolutely fundamental, and of immeasurable import for the whole of philosophy. ... everything qualitative or related to content in our experience must forever remain private and can in no way be known in common to many individuals. However paradoxical it may sound, it is literally true that all our statements, from the commonest utterances of daily life to the most complex assertions of science, reflect only formal relations of the world, and that nothing of the quality of experience enters into them.2

It was a confirmation of this epistemology that Schlick was now expecting from the two authors he mentioned in his footnote: Cf. the acute and irrefutable remarks of Rudolf Carnap in his forthcoming work, Der logische Aufbau der Welt, where he shows that all scientific judgements must confine themselves to purely structural assertions – this concept corresponds to our ‘formal relations’. We may add that this holds good of all meaningful judgements whatsoever, since the arguments remain valid for all statements, even the non-scientific ones. Cf. also Ludwig Wittgenstein, Tractatus Logico-Philosophicus, ...3

THE FORMATION OF A NETWORK

Schlick had published a revised edition of his Allgemeine Erkenntnislehre in 1925, but it was not a foundation for the Circle that was gathering around him, with the sole exception of Herbert Feigl. Schlick’s encounter with the thought of Wittgenstein and also with that of Carnap made him feel that philosophy should take a completely new path. This was reflected in a letter he wrote to Ernst Cassirer in March 1927. Schlick was ashamed of his own epistemology: Ich bin seitdem durch die Schule der Logik Russells und Wittgensteins hindurchgegangen und stelle seitdem an das philosophische Denken so verschärfte Anforderungen, dass ich 133 F. Stadler (ed.), The Vienna Circle and Logical Empiricism: Re-evaluation and Future Perspectives, 133–150. © 2003 Kluwer Academic Publishers. Printed in the Netherlands.

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die meisten philosophischen Erzeugnisse nur mil grösster Selbstüberwindung lesen kann. Den Tractatus logico-philosophicus von Wittgenstein halte ich für die genialste und bedeutsamste Leistung der gegenwärtigen Philosophie. Leider ist er so barock geschrieben, dass wir in meinem philosophischen Zirkel (an dem hauptsächlich mathematische Kollegen teilnehmen) drei Semester gemeinsamer Lektüre gebraucht haben, um uns zum Verständnis durchzudringen. Auch die Persönlichkeit Wittgensteins (der wahrscheinlich nie mehr etwas publizieren wird) ist wahrhaft genial. Ich glaube fest, dass die Philosophie durch die von der neuen Logik ausgehenden Impulse an einen Scheideweg gelangt ist und dass wir uns dem Leibnizschen Ideal des Philosophierens nähern. Die Grenze gegen leeres Reden und Fragen wird noch viel schärfer gezogen werden mussen als bisher. Wir dürfen, glaube ich, unerschütterlich an dem Satz festhalten, dass alle richtig gestellten Fragen prinzipiell lösbar sind, und zwar entweder durch logische Analyse oder durch empirische Feststellung, und das die “unlösbaren Probleme” nur falsch gestellte Fragen sind. Ich hoffe sehr, dass die Wiener Philosophen in der nächsten Zeit auch einige Beispiele der exakten Methode vorlegen werden, die in Vorbereitung sind ... Ein wirklich glänzendes und durchaus grundlegendes Werk dieser Art stellt das Buch Der logische Aufbau der Welt von Catnap dar, der in vergangenen Semester hier bereits gelesen hat. Es macht mit der logischen Methode Russells ernst und wendet sie mit wahrhaft erstaunlichem Erfolge auf die Fragen der Philosophie, z.B. das Kategorienproblem an.4

Schlick had been the first philosopher to understand and defend Einstein’s theory of relativity. Now he felt that something as momentous was happening in philosophy. Again, his services were needed. The problem with Carnap’s book was that it had been lying around for a year but that it was still without a publisher. The huge manuscript containing 566 pages was rejected again and again. Carnap was prepared to delete about a hundred pages, but Schlick was opposed to this. Thus Schlick continued his letter to Cassirer with a request for a favor, knowing that the philosopher’s brother Bruno Cassirer was a publisher in Berlin. The result was that Ernst Cassirer immediately explained the situation to his brother, who in turn wrote to Carnap asking for more information. But in those economically hard times the risks connected with a book of that size were again seen as too high. Schlick had better luck with Wittgenstein who had come back to Vienna to carry out his architectural project. After meeting the man he considered a genius, he was able to organize a series of meetings between Wittgenstein and the younger members of his Circle. Carnap, of course, was present, and so was Herbert Feigl, Friedrich Waismann and Maria Kaspar.5 Wittgenstein, despite his studies with Russell in Cambridge, was as much a Viennese as anybody can be, and he most certainly became a member of Schlick’s network. The idea that Carnap should be a Viennese philosopher was of a much more recent origin than the book that he was writing. Carnap began his studies leading to the book the very same year that Schlick abandoned his earlier post in Rostock and took over the chair in Vienna, in 1922. He took the initiative for the meeting in Erlangen in 1923 where the idea of an exact philosophy, using the logic of Russell, was born in Germany.6 On the very second day of the meeting, Hans

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Reichenbach wrote to Schlick about the need for a journal dedicated to the new philosophy, and he remained the main spokesman for the idea.7 The members of the First Vienna Circle that had gathered together before World War I also had a constitutive role in the founding and work of the Second Circle known as Schlick’s Circle.8 The mathematician Hans Hahn, the physicist Philipp Frank and the economist Otto Neurath were all shaping the Viennese intellectual milieu in their own ways. Frank held Einstein’s former chair of physics in Prague. Reichenbach had only a minor post as an assistant at the Technical University of Stuttgart, but he was busily planning the new journal together with a monograph series. He would have the main responsibility and the publisher would be the Springer Company operating in Berlin and Vienna. However, Springer had been planning to have Frank and Schlick as the editors of a series of monographs in the natural sciences, and now the plans took a different twist. These two had academic chairs and careers that overshadowed Reichenbach, and they were asked in 1925 to edit a completely new series entitled Schriften zur wissenschaftlichen Weltauffassung.9 Frank was planning a new chair for the philosophy of nature at the University of Prague, the speciality of the chair being defined in complete accordance with the interests of Reichenbach. However, with the help of the Berlin physicists, including Einstein, Reichenbach was soon appointed to an extraordinary chair for natural philosophy in Berlin. Carnap was now looking to Prague. In a letter to Schlick at the beginning of 1926 he wrote: Ich bekam einen erfreulichen Brief von Herrn Prof. Frank, dass man mich für eine neu zu schaffende Lehrkanzel für Naturphilosophie in Betracht ziehen werde. Frank hat ja anscheinend mit Ihnen darüber gesprochen. Da er angibt, dass die Sache soweit in Zukunft liegt, dass ich auch im günstigen Falle die Wiener Privatdozentur einige Zeit würde ausüben können, so habe ich ihm meine grundsätzliche Bereitwilligkeit ausgesprochen. ... Jedenfalls bin ich zunächst eindeutig auf die erstrebte Wiener Tätigkeit eingestellt und bereite mich innerlich auf diese vor.10

Carnap was still living in Germany, in Buchenbach near Freiburg. The book was growing to about twice the size of the originally planned 300 pages and Vienna had to wait for its completion. It was a precondition for a lecturer to present the manuscript as a Habilitationsschrift. Finally, in 1926 Carnap was able to give the MS to Vienna, but he missed the Circle’s reading of Wittgenstein’s work. Still he hoped “mindestens noch die Nachwirkungen einmal spüren zu können”.11 NEURATH’S COMMENTS TO CARNAP

After only short visits to Vienna Carnap was able to begin his lectures near the end of 1926. By then his MS had already been circulating among the members of Schlick’s Circle. However, the reception of the book was not only laudatory in the style of Schlick. One harsh criticism came from Otto Neurath, but Carnap

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had the patience to listen to criticism and to different philosophical views. Neurath was not one of Schlick’s favorites. His loud voice and his straightforward habits annoyed Schlick, but as a member of the First Circle, Neurath was still unavoidably part of the world that Schlick was inhabitating in Vienna. In addition, Neurath was philosophically and politically a good friend of Frank and a representative of the Austrian radical wing Social Democrats. On November 21, 1926, Carnap jotted down some of Neurath’s objections: Meine Darstellung sei leider mehr gegen Realismus als gegen Idealismus gewendet. Zu starke Betonung des methodischen Solipsismus. Das klinge zu individualistisch. Mehr den “Objektivismus” betonen. Gleich zu Anfang sagen, dass das Ziel eine objektivistische Welt, die gleiche für alle Individuen, sei. 12

It is clear that this was a summary of Neurath’s wishes. Carnap’s second note can be seen as belonging to the same category, but it can also be his attempt to take into account the main emphasis of Neurath’s objections: § 224 Der Realismus des Physikers bleibt bestehen, nur wird er korrigiert zu einem Objektivismus. Vielleicht so: Die gesetzmässigen Zusammenhängen sind objektiv, d.h. dem Willen des Einzelnen enthoben; es gibt aber keine Materie, der man “Realität” zusprechen könnte; das ist ein metaphysischer Begriff.13

Neurath had also made some suggestions about how the text could be condensed. Among them was the proposal to leave out Chapter V. In Carnap’s letter to Schlick in May 1926 the content of Chapter V was explained: philosophical problems. At that time, Carnap himself had been prepared to exclude it: “... könnte ganz wegfallen, da er für den Zusammenhang der Darstellung der Theorie nicht notwendig ist, sondern nur Anwendungsbeispiele bringt; möglicherweise lässt er sich dann später zu einer selbständigen Veröffentlichung verarbeiten.” 14 But now, probably because of Schlick’s attitude against the shortening of the MS, Carnap commented: “Vielleicht ja, aber dann das wichtigere daraus in die vorderen Abschnitte verarbeiten.” 15 Carnap’s last note is enigmatic, not because of its content, but because of its origin: S. 566. Es wird zuweilen gesagt, dass dem praktischen Verfahren der Realwissenschaften, insbesondere der Physik, ein unausgesprochener Realismus zugrunde liege. Hier muss aber deutlich unterschieden werden zwischen der Verwendung einer gewissen Sprache und der Behauptung einer These. Die realistische Einstellung des Physikers äussert sich zunächst in der Verwendung der realistischen Sprache; sie ist berechtigt und häufig zweckmässig und berechtigt (vergl. § 52). Ein darüber hinausgehender Realismus als explizite These ist dagegen unzulässig; er muss zu einem “Objektivismus” (wenn man so sagen will) korrigiert werden. Die gesetzmassigen Zusammenhänge (die in den Naturgesetzen als Implikationen formuliert werden), sind objektiv, dem Willen des Einzelnen enthoben; dagegen würde die Zuschreibung der Eigenschaft “real” an irgendeine Substanz (sie sei nun Materie, Energie, elektromagnetisches Feld oder was immer) aus keiner Erfahrung herzuleiten, also metaphysisch sein.16

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The reference to page 566 alluded to the last page of Carnap’s own MS, but Carnap was certainly not quoting from his own MS. So how much of the passage quoted belongs to Neurath and how much to Carnap? Carnap included the passage without any alteration of content in his final printed Der logische Aufbau der Welt, where it is to be found as the last paragraph of Part V, §§ 175-178 on the metaphysical reality problem. The passage was probably Carnap’s own formulation to which Neurath’s objections gave rise. It was a denial of metaphysical theses, but an acknowledgement of the justified use of realistic language in physical science. But was this something new with respect to the original MS? The question must be left unanswered at this stage. In any case, it can be observed that there was also a fundamental agreement between Neurath and Carnap. In fact, it was the very same feature that attracted Schlick. Carnap recorded Neurath as commenting: Gut ist: dass der gesamte Raum auf einmal konstituiert wird; nicht ein ganzes aus Teilen zusammengesetzt! Sondern die Teile bekommen erst ihre Bedeutung aus dem Ganzen. (Das ist ja überhaupt eine grundsätzliche Einstellung der Relationstheorie: Die Glieder bekommen ihren Charakter nur durch ihre Stellung im Ganzen).17

The shift toward the acknowledgement of the realism implied by the language of the physicists was a significant step. A precondition for it had been the concentration on language that Wittgenstein had prepared and that was adopted by the Vienna Circle. It is not important whether Carnap’s remarks were written down immediately after Neurath’s comments or only later. The important thing is that Carnap no longer was completely “neutral” in his conception of science and that he still was not forced to make concessions to ontological metaphysics. Carnap’s first approach had been neutrality backed by a belief in the power of topology and Bertrand Russell’s logic of relations. That kind of exact or scientific philosophy had been the theme of the meetings in Erlangen where Carnap circulated the first sketch of his forthcoming big book, then entitled Vom Chaos zur Wirklichkeit. There seems to be no indication of an essential change of his programme before his remarks on the comments made by Neurath. In the invitation to Erlangen, Carnap had stressed that the discussions should concentrate on die methodischen Prinzipien zur Konstituierung der “Naturwirklichkeit” aus dem “Gegebenen” und die Struktur des Wirklichkeitsbereiches. “Wirklichkeit” im Sinne der materiellen oder physischen Welt, “Aussenwelt”; “das Gegebene” im Sinne der ungedeuteten Sinnesempfindungen (Machs “Elemente”, Ziehens “Gignomene”). Alle diese Ausdrücke sind ohne ihre metaphysische Nebenbedeutungen zu verstehen; neutral ausgedrückt: Konstituierung des sekundären Bereiches aus dem primären. Die metaphysische Frage nach dem Realitätswert der beiden Bereiche wird nicht behandelt (z.B. ist das Primäre “bloslich Gegebene” und das Sekundäre eine “ökonomische Fiktion”?) 18

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Reichenbach was immediately critical of Carnap’s approach when he read the MS of the big book. But he had nothing new to offer, only a plea for a realism of the external world.19 Later on, Carnap’s terminology of a “primary” and a “secondary” area or system began to circulate in Vienna, as was evidenced by Wittgenstein’s adoption of it.20 A quite different development became viable when Carnap agreed, in his notes on Neurath, that the physicist’s realistic language was practical and justifiable, as opposed to realism as an explicit thesis. The epistemological path was now in need of a complementary treatment, doing justice to the ways of science.

A REMARKABLE YEAR OF CRYSTALLIZATION

In the fall of 1927, Frank wrote to Schlick about the planned monograph series they were to edit together. He listed of seven authors and their themes, among them Otto Neurath and “die Fragen einer exakten Wertrechnung, insbesondere über ihre Möglichkeit”.21 It was not listed among the books that were to appear first. Later, when the Circle had gone public, Neurath’s theme was announced in a different form: Der wissenschaftliche Gehalt der Geschichte und Nationalökonomie, vol. 4 of the series. Finally, in 1931 Neurath’s Empirische Soziologie really appeared in the series with the title announced earlier as its subtitle and with a changed volume number, number 5. The delay cannot be explained simply by the fact that Neurath had no academic position and no opportunity to be a full-time writer. The theme that Frank mentioned in his letter was one that had been attracting Neurath since before the First World War, but there is no indication that he began to work on it when the planning of the book series started. It is probable that Neurath had talked about it with Frank only to reserve a place for the scientific book that he would like to write. Four of the names on Frank’s list were members of the First Vienna Circle: Frank, Hans Hahn, Neurath and Richard von Mises. The logician Paul Bernays and the physicist Paul Hertz, both from Göttingen, were also on the list. Hertz had edited together with Schlick the epistemological writings of Hermann von Helmholtz. Frank mentioned further the contributions of “Karnap” whom he apparently knew through discussions with Schlick. And in a second letter Frank agreed with Schlick’s proposal to include Friedrich Waismann.22 The first book to appear was in fact that by von Mises, his Wahrscheinlichkeit, Statistik und Wahrheit. It was published as vol. 3 in 1928. The second book was Carnap’s Abriss der Logistik, published as vol. 2 in 1929. As time went on, Bernays, Hahn and Hertz withdrew from the project and new authors appeared on the scene. Waismann’s book never actually appeared in the series, but it would be constantly in preparation and despite the publisher’s protests Schlick reserved for it the number 1 for all eternity. The summer of 1927 was quite unique in the history of the Vienna Circle. Schlick was sure that philosophy had come to a turning point. Both Wittgenstein

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and Carnap, in Schlick’s eyes the main figures behind the big reform, were in Vienna. Discussions with everybody were possible, both in Schlick’s official seminar and outside it. Of course, Neurath had been critical of Wittgenstein and the “metaphysics” he saw in the Tractatus. Thus the genius could not be brought together with Neurath in the formal seminar, but Schlick’s network was not restricted to the meetings on Thursday evenings. Schlick could not foresee that communication between Carnap and Wittgenstein would come to an end after only a few meetings. However, something from the encounter with Wittgenstein’s Tractatus was impregnated in everybody within the Circle. A touch of Wittgenstein was the Circle’s distinguishing feature, for instance, as compared with Reichenbach’s Circle in Berlin.23 Even Neurath admitted later to a young friend of his: Wir – die älteste Gruppe – hatten Logisierung, Axiomatisierung geschätzt, was die Publikationen deutlich zeigen, aber jene Betonung des logischen Instruments war uns nicht so wichtig erschienen, das Problem der Sprachanalyse nicht so abgesondert zum Bewusstsein gekommen. Da war die Lektüre Wittgensteins sehr heilsam. Einerseits entwickelte sich so zum ersten Mal die gemeinsame Plattform so richtig, andererseits entstanden so die ersten Keime gewisser Gegensätze.24 For Carnap, the summer of 1927 also meant a renewed and deeper contact with Neurath. This time Carnap was lecturing in Vienna from the beginning of May and he left the city only after the first week of August. In addition to the meetings of the Circle and the meetings with Wittgenstein Carnap had meetings in Neurath’s home where Neurath’s wife Olga, Hahn’s sister, also was present, together with Friedrich Waismann. The letters sent the next winter contain remembrances of this “unofficial” Circle. Carnap did not come to lecture in Vienna in the winter 1927/1928. He went to Davos in Swizerland for health reasons, but he continued writing at an unhealthy pace. On the last day of 1927, Neurath sent Carnap a letter displaying both politeness and undoubted genuine feeling: Lieber Carnap! Gute Grüsse, Frohe Weichnachtswünsche von mir, meiner Frau und unserem Symphilosophanten Waismann, ditto Neujahrswünsche! Ich nehme wenige ehrwürdige Philosophen öfter zu mein ungewachsenes Maul, als gerade Sie – anerkennend und milde aberkennend. Es wäre mir wesentlich wohler auf Erden, wenn Sie den Ruhm der “Wiener Schule” vermehren würden nicht in Davos, sondern meinen altmodischen Räumen – Lassen Sie es sich gut sein, schreiben Sie mir und meiner Frau, die wir Sie lieb haben. Schreiben Sie lang, belebt und belehrend, uns, die wir der Weisheit beflissen, die Verknüpftheiten des Daseins erleben und kaum durchschauen. Ihr O.N.

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[Here was a picture drawn by Neurath, presenting two dragonheads threatening each other but with one body, J.M.] Alles Schöne zum Neuen Jahr! In den nächsten Tagen schreibe ich ausführlich. Fritz Waismann 25

Carnap began his reply when his stay in Davos was coming to its end. The letter to “Lieber Neurath und liebe Neuräthin” had the first sentence dated February 25, 1928 in Davos, and the rest March 3, 1928 in Tyrol. Carnap wrote: Auch ich freue mich darauf, im Sommer wieder in Wien sein zu können und dann mit Ihnen wieder unsere Diskussionen aufzunehmen. Oder haben Sie inzwischen schon mit Waismann das geschichtsphilosophische Thema zu einem abschliessenden Ende gebracht? Es wird uns aber an Problemen niemals fehlen, denke ich. ... Ja, die Verknüpftheiten des Daseins sind wohl manchmal schwer durchschaubar, aber ich bin trotzdem nicht geneigt, sie als ein dräuendes Drachengewirr [a reference to the picture drawn by Neurath, J.M.] anzusehen; ich denke, dass sie sich schon irgendwie entwirren werden, wenn man sie mit Zuversicht, Ruhe und Geduld ins Auge fasst.26

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This was actually what Carnap had done during the winter. First, he finished his Abriss der Logistik, accepted for the Circle’s series. The manuscript was not too long. It did not need much editing. Second, he wrote the Aufbau afresh and decided on how to publish it. The manuscript had been rejected by Meiner, Mohr, Cassirer, Markus, de Gruyter and a few others. In Schlick’s opinion, the big book should have been volume number one in the Schriften zur wissenschaftlichen Weltauffassung, beginning the whole series, but Schlick did not succeed in persuading the publisher to make such a spectacular prelude.27 Springer had shown interest in the book, but would make no commitment until seeing how the smaller Abriss sold. Carnap felt that he could not wait. Wilhelm Benary had advised applying for subsidies from the Notgemeinschaft Deutscher Wissenschaft.28 Benary was running the Weltkreis publishing company which had a small but impressive profile. Weltkreis Verlag in Berlin had grown out of the now defunct Erlangen Academy where the first colloquium of scientific philosophy had been held and Benary had edited the Academy’s journal Symposion where Carnap had already published some of his work. Before Carnap left Vienna in the summer of 1927, he learned that he would get from the Notgemeinschaft a sum of 1000 German marks for the publication of the Aufbau.29 It was then that Carnap sold his house in Jena and so he had some money that he decided to put into the same project with the Weltkreis company as publisher.30 Thus in Davos, Carnap had devoted his energies to his MS, rewriting substantial parts of it.31 Thirdly, Carnap also decided to use the Weltkreis also to publish as a small book two of his essays that had been rejected by the journals KantStudien and Annalen der Philosophie. This book was to be the Scheinprobleme der Philosophie. Das Fremdpsychische und der Realismusstreit (1928). The health cure in Davos had been effective, and Carnap then spent a couple of weeks in Tyrol. NEURATH’S UNPUBLISHED MANUSCRIPTS

The discussions in Vienna in the summer of 1927 also seem to have prompted Neurath’s activity. Unlike the Abriss and the Aufbau, Carnap probably wrote the two essays that were to form his Scheinprobleme in Vienna. The manuscripts of the small pieces were certainly debated in Neurath’s Circle. This can be inferred from a letter that Carnap sent to Neurath in October 1928: “Heute erhielt ich eine Karte von Ph. Frank über die Scheinprobleme. Ich zitiere daraus, weil es Sie und besonders Ihre Frau sicher interessieren wird, die ja an dem MS so tätigen Anteil genommen hat...” 3 2 It is said that Olga Neurath never spoke in Schlick’s Circle, but the opposite seems to have been the case in a smaller and more familiar circle. In the same letter, Carnap sent his regards to “Liebe Frau Neurath!” concerning their recent discussion of the views of Eino Kaila with whom Carnap was then corresponding about the structural conception of knowledge. Olga Neurath ought to call

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Waismann and ask him to read from Kaila’s letters the passages about the reality problem, obviously confirming Carnap’s confidence in Kaila.33 It was quite natural that Olga Neurath, the blind female logician, was enthusiastic about Carnap’s relational, structural conception of knowledge. And again we find Carnap in contact with the Neuraths and in the company of Waismann. Back in the summer of 1927 Neurath was either writing his Marxist book Lebensgestaltung und Klassenkampf (l928), or – possibly – awaiting its publication. Toward the end of the book Neurath expressed his hopes that the working class would take over the task of carrying on science without metaphysics.34 What exactly was “the theme in the philosophy of history” that Carnap had been debating with the Neuraths in the summer of 1927 and to which he wanted to return again the next summer? What did Carnap mean here with his talk of Neurath’s and Waismann’s joint work that they would continue while he was absent? In the Vienna Circle Archives of the Rijksarchief in Noord-Holland, Haarlem, there are two unpublished manuscripts entitled Der wissenschaftliche Gehalt der Geschichte und Nationalökonomie. One of them is handwritten, contains 65 pages and has the code K.3. The text is written on the right sides of the notebook with a few additions on the blank left sides, sometimes even in the margins. The second one is typewritten. It consists of 155 pages, including some advice for the printer. In the eyes of its author, it is a finished MS. It has the archive sign K.2. The shorter text is the older one. The longer text is definitely from a later time. The older text is very tentative. Let us call it the WG1 and the other one WG2. The earlier MS probably dates from the summer 1927 or from the months immediately following it. The text is by no means finished, but a sketch of interconnected themes, of something only in the planning. The handwriting of the sketch is not Neurath’s. A comparison with Waismann’s handwriting from manuscripts in the Bodleian library, Oxford, shows that it was Waismann who wrote down Neurath’s ideas.35 I cannot exclude the possibility that WG1 was already written before the summer of 1927, but there are indications that it was written just that summer or a little afterwards, at the same time as and independently of Carnap’s Davosian efforts. Actually, Carnap’s letters to Neurath contain almost a definite description of the process that led to WG1. The title of the MS suggests that the author was aware of attempts to formulate a criterion of “scientific content” with the aim of separating science from metaphysics. Carnap’s two Viennese papers that Neurath read in the summer of 1927, the later Scheinprobleme, developed this line of thought. According to Carnap, every scientific proposition had to express a state of affairs consisting of elementary experiences. Neurath had no sympathy for such experiences, but he was eager to find ways of separating science from metaphysics. Both the WG1 and Scheinprobleme are concerned with this task, but in different ways. Characteristically, Carnap was in search of a logical criterion, whereas Neurath believed that only by developing a new, structurally oriented science could everyday intuitions be left behind.

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OF

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Neurath’s WG1 was a the sketch for a study of concept formation in history and the social sciences. It was concerned with the language, conceptual structure and, in the end, with the common tasks of all areas of research, seeing them in a perspective which contains a number of the elements of Neurath’s later physicalism, but not all of them. It was completely different from the explorations in Lebensgestaltung und Klassenkampf, and it belongs clearly to the history of the Vienna Circle. Neurath’s manuscript was not concerned with Carnap’s method of constitution, his quasi-analysis, or with the Russellian part of Carnap’s programme. Instead, Neurath’s text began directly with the quantitative physical world and the presuppositions for its description. Das physikalische Weltbild ist dasjenige Weltbild, welches unabhängig von der spezifischen Sinneserfahrung ist. (Gegen Mach. Mach stützt den Individualismus!) Objektiv kann nur dasjenige Weltbild sein, das allen Erfahrungen gemeinsam ist – daher ist es mathematisch. Blinden und Tauben muss etwas gemeinsam sein. Dass es etwas gemeinsames gibt – das physikalische Weltbild – ist nicht selbstverständlich.36 For Neurath, numbers were the basis for intersubjective knowledge. People could agree about them much more easily than about such subjective elements as sensory qualities like colors. This pragmatic argument was in accordance with Neurath’s work in visual statistics. In Neurath’s opinion, the physical world picture was both intersubjective and intersensual. But is it also universal? In the WG1, Neurath denies the possibility of this universality: Die Welt könnte in Teilwelten zerfallen, die nichts gemeinsam haben – ja, jede solche Welt könnte noch für sich mathematisierbar sein, ohne dass es ein gemeinsames Weltbild gäbe. ... Es kann Welten geben – aus verschwommenen Objekten, nebelgleich ineinander fliessend, ohne scharfe Grenze, ja ohne schaft gesonderte Sinnesqualitäten – die sich der Logik und Mathematik entziehen.37 In this and other passages Neurath argued against the universality of physics. He was skeptical about Carnap’s ideas: “Prinzipiell lässt sich alles darstellen wie das Physikalische. Aber diese Möglichkeit ist noch weit entfernt von der wirklichen Durchführung. Gefahr der Überschätzung des Bloss-Möglichen (z.B. bei Carnap).” 38 In his essays on the history of optics, Neurath had adopted the specific view that Pierre Duhem had about the relations of everyday language and the concept formation of physics. Duhem had thought that at the bottom of our most clearly formulated doctrines we always find a confused collection of common sense truths that are deficient in detail and precision, unable to be decomposed into

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simpler elements. Still, “all scientific clarity and certainty are a reflection of the clarity and an extension of the certainty of these common sense truths”.39 Duhem presupposed a continual circulation and a “mixed zone” between these two: “... physical science is both certain and clear because the streams which spring from these two sources run together and mingle their waters intimately.” 40 In the WG1, Neurath coined the term Ballungen or “aggregations” for these imprecise and yet important elements of everyday experience. He introduced the term with a reference to the holistic outlook that was being developed in Gestalt psychology as a criticism against Mach. Everyday objects escaped the purity of both the phenomenal and the physical. However, there was nothing wrong with them: Das meiste, worüber wir Aussagen machen, ist gar nicht präzisiert. Die Schwierigkeiten beginnen erst mit dem Präzisieren. Unpräzisiert sind manche Aussagen oft ganz richtig und werden erst problematisch, wenn sie präzisiert werden sollen. Wir haben eine lange Erfahrung, mit Begriffen zu hantieren, die nicht ganz präzis sind.41

Developing the ideas first presented in his essay about the lost wanderers of Descartes (1913), Neurath emphasised the importance of decisions for all of science. A preliminary map can only be made better by adopting it, working with it and then correcting it. Science was just such a map. Research presupposed continuous decision making. Metaphysics was the result when these decisions were made tacitly. Once one became aware of them, metaphysics was obsolete.42 But this was also true of the philosophy of history. According to Neurath’s view, every comprehensive philosophy of history was built on decisions. Consequently, none should ever be upheld by coercive means against dissenters. “Ich möchte zeigen, dass das Ergebnis einer geschlossenen Geschichtsauffassung ein Entschluss ist und nicht eine durch Erfahrung gegebene Tatsache. Ich möchte zeigen, dass die Erfahrung stets vieldeutig ist.” 43 History and the social sciences were at bottom unified and embedded in a broader context of nature. Only the living conditions of people can be seen as something immediately given, but one should search for structures that were theoretical constructions. In the manuscript, Neurath did not deny the necessity of empathetic understanding in the social sciences. In the course of time such an approach could perhaps be replaced by a more scientific one, but Neurath was still warning about overrating causalistic ways of thought. Neurath was sure that there were objects that should be eliminated altogether from a scientific approach, for instance the racial construction of history. However, Neurath did not find it easy to delineate the objects of history and the social sciences. Actually, the sketch ended with an open question: “ Welche Objekte gestatten zusammenfassende Aussagen?” 44

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THE SIMULTANEOUS BIRTH OF TWO PHYSICALISMS Neurath’s remarks from the end of the year 1926 were not unimportant to Carnap when he finally rewrote his Aufbau. One has to keep in mind that these remarks were followed by intensive discussions in the summer of 1927.45 There was an important passage in the notebook that found its way directly into the Aufbau. Moreover, Neurath suggested that Carnap should say in the very beginning that the aim of the book was an objectivistic world shared by all individuals. Carnap did what he was encouraged to do, saying exactly this at the end of his § 2. With the original manuscript still missing, it is difficult to speculate what else there might be along the same lines. All traces have not been lost, however. Special weight must be given to a letter that Carnap wrote while revising and completing the book. Carnap’s family had come to Davos for Christmas, but the philosopher still wrote a letter to Schlick. He was wondering whether he should save the name of the book, suggested by Schlick, for a later, quite different study. The title was now misleading, he explained: Der bisher beabsichtigte Titel Der logische Aufbau der Welt. Versuch einer Konstitutionstheorie der Begriffe scheint mir in Konflikt zu geraten mit einer Arbeit, die ich für später plane. Das Konstitutionssystem des Buches hat eine eigenpsychische (“solipsistische”) Basis. ... An einer Stelle des Buches deute ich kurz an, dass ein anderes Konstitutionssystem möglich ist; mit physischer (“materialistischer”) Basis. Reihenfolge: Physisches, psychisches (ohne Unterscheidung des Ich), Geistiges. Die Leistung dieses Systems ist eine andere: es dient nicht der Erkenntnistheorie, sondern der Realwissenschaft. Es hat als Basisgebiet dasjenige Gebiet, das als einziges eine durchgehende eindeutige Gesetzmässigkeit seiner Vorgänge besitzt. Die psychischen und geistigen Gegenstände werden hier aus den physischen konstituiert ... Das zweite System kann aber vielleicht stärkeren Anspruch auf den Namen geltend machen: es baut die Wirklichkeit auf als das eine gesetzmässige Gesamtgeschehen in Raum und Zeit; und ist es nicht vor allem dieser Geschichtspunkt, den wir in der Realwissenschaft bei dem Wort “Wirklichkeit” vor Augen haben? 46 However, Carnap did not change the title to Erkenntnislogik or to Der logische Aufbau der Erkenntnis as he was planning. In this, he followed Schlick’s advice to keep the old name. When Carnap left Davos, he sent Neurath a copy of the page pondering the title, with the following wishes: ... da Sie, wie ich vermute, gerade besonderes Interesse haben werden für das Begriffssystem mit physischer Basis. Ich vermute, dass wir über die Mehrleistung, aber auch über die Wenigerleistung dieses Systems im Vergleich zu dem mit eigenpsychischer Basis einig sein werden.47 Why did Carnap not suggest anything similar to Schlick? Of course, he had discussed these questions with Neurath, and he knew Neurath’s philosophical

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preferences which were quite different from Schlick’s. Moreover, the letter could be read as an invitation to continue the memorable discussions. Neurath’s WG1 did not, in fact, go as far as Carnap. What Carnap called “eine [sic!] gesetzmässige Gesamtgeschehen” as it was characterized physically in time and space would also be an answer to Neurath’s concerns about the objects of history and social science. When the Aufbau appeared in August 1928, Neurath could read that fundamentally there is only one object domain and that each scientific statement is about the objects in this domain.48 Carnap’s one domain thesis, a corner stone of the Aufbau, may, of course, be much older than the book, even a continuation of his old interest in monism. What made the thesis appealing to Neurath was that this system could also be construed in a physical, materialistic way. Thus, in his WG2, Neurath was no longer worried about the limits of physical language. Within Schlick’s network, criticism against the Aufbau was launched very soon. In January 13, 1929, Kaila said in a letter to Schlick how very much he was interested in the “von Ihnen angedeutete, von Wittgenstein gegen die Konstitutionstheorie erhobene Einwand, dass es nämlich unmöglich sei, ‘von den Momentan-Gesamt-Erlebnissen als Basis auszugehen’ ”.49 A few days later, Carnap noted in his diary: “(Nachdem ein [fruchtloses] Gespräch vorhergegangen, in dem Waismann vergeblich bemühte, Wittgensteins Meinung deutlich zu formulieren.)” And further: “Über Extensionen. Veranlasst durch Wittgensteins Kritik der Quasianalyse (über die wir gestern gesprochen haben) wollen wir einige logische Fragen klären.” 50 These discussions with Waismann and Feigl continued for a number of days in a stricly logical form, but nothing that could be called “physicalism” was formulated. Neurath was not present, Wittgenstein had already left for Cambridge. Wittgenstein certainly was a critic of Aufbau’s starting point and its method, but somehow he did not succeed in saying clearly enough what he had to say. If he had something to replace Carnap’s approach, its meaning remained buried and hidden from the Circle, at least from Neurath and Carnap. At the Circle’s first conference in Prague, September 1929, Neurath introduced unified science. In the next winter he wrote the first draft of the book planned to carry the title of WG. It was announced that the new book would appear in the Schriften zur wissenschaftlichen Weltauffassung, but Schlick was horrified with the MS and especially with its exclamatory style. He rejected the book.51 Carnap saw himself in an embarrassing position and offered Neurath help in rewriting the book.52 Independently, Neurath produced another draft in an astonishingly short time, in just a few weeks. At the beginning of August 1930, Carnap was in Biberwier, Tyrol, together with Feigl and Kaspar. Two years later he told Schlick that he had written the first draft of the essay ‘Die physikalische Sprache als Universalsprache der Wissenschaft’ during that summer visit.53 A card that he sent to Schlick from Biberwier reveals how worried he was about the conflict between Schlick and

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Neurath. Carnap was not allowed to make improvements to Neurath’s MS, but instead wrote a paper of his own on the same theme. Then, at the end of the same month, Carnap met Neurath in Vienna, still in the company of Feigl. He wrote to Schlick: Wir haben ihm ruhigend zugeredet. Er war nämlich immer noch erregt und glaubte, dass nicht nur dem MS, sondern ihm persönlich Ungerechtigkeit widerfahren sei. Und nun hatte er tatsächlich schon ein beinahe fertiges neues MS! Er hat uns verschiedene Kapitel daraus vorgelesen. Und wir waren erstaunt zu sehen, dass er hier wirklich in ganz anderem Tone geschrieben hat, sachlich argumentierend, und ernsthaft in der Formulierung. Der Inhalt ist jetzt ein ziemlich anderer, mit gleichen Grundgedanken.54

It was important for Carnap to resolve the conflict as soon as possible, since he was at least partially responsible for the whole. The first chapter of the manuscript WG2, which was omitted when the Empirische Soziologie was finally published in 1931, was not uninteresting. It was there that Neurath first formulated all of the main characteristics of his physicalism: the intersubjectivity, intersensuality and universality of physical language with a starting point in the Ballungen of our everyday language.55 However, Neurath did not yet use the term “physicalism”. This was a term that he seems to have adopted only later in 1930. The WG2 was an openly Marxist text, an attempt to join together Marxism and the Vienna Circle. Neurath’s physicalism was an attempt to present some of his main convictions along these lines in a form that would also be worthy of debate in Schlick’s Circle. With Carnap’s support, the introduction of physicalism succeeded in the spring of 1931, and later on.56 But soon, in the political upheavals of Europe all of Marxism turned out to be a disappointment for Neurath. He never became apolitical, but his interests shifted after his emigration, first to an encyclopedic form of physicalism, then to a defence of a democratic pluralism which he saw as intimately connected with a denial of all “systems” built on One World assumptions.57 Who was the first to discover physicalism? The question does not make much sense. Neurath and Carnap were time and again interacting with each other over the course of years, stimulating and criticising each other, and writing independently of each other. Their personal styles, views and aims were so different that it is not altogether easy to describe them as participating in a joint venture. Nevertheless, they shared a common interest in a uniquely close way. The best picture of the situation was probably Neurath’s drawing of the two dragons with one body. When they published their articles on physicalism in the Erkenntnis in 1932 and Carnap gave priority to Neurath, he was speaking only part of the truth. He forgot to mention his own role in the complicated story that had begun in Vienna way back in November 1926.

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Acknowledgments: I am particularly indebted to Dr. Brigitte Uhlemann (Konstanz) for her transcriptions of Rudolf Carnap’s texts written with a shorthand and for the Archives of Scientific Philosophy (Pittsburgh University) and the Vienna Circle Archives (Rijksarchief in Noord-Holland, Haarlem) for their permission to quote unpublished archive sources.

NOTES

1.

2. 3. 4. 5. 6.

7. 8.

9. 10. 11. 12.

13. 14. 15. 16. 17. 18. 19.

20.

M.Schlick, Philosophical Papers, Vol. II (1925-1936), ed. by H.Mulder and B.F.B. van de Velde-Schlick, D.Reidel, Dordrecht 1979, p.99. Cf. M.Friedman, Reconsidering Logical Positivism, Cambridge University Press, Cambridge 1999. Ibid., p. 102. Ibid., p. 1 1 1 . M.Schlick to E.Cassirer, March 30, 1927. The Vienna Circle Archives in the Rijksarchief in Noord-Holland, Haarlem (=VCA). F. Stadler, Studien zum Wiener Kreis. Ursprung, Entwicklung und Wirkung des Logischen Empirismus im Kontext, Suhrkamp, Frankfurt am Main 1997, pp. 473-4. See C.Thiel, ‘Carnap und die wissenschaftliche Philosophie auf der Erlanger Tagung 1923’, in: R. Haller and F. Stadler (eds.), Wien-Berlin-Prag. Der Aufstieg der wissenschaftlichen Philosophie, Hölder-Pichler-Tempsky, Wien 1993. H.Reichenbach to M.Schlick, March 8, 1923, VCA. Reichenbach planned that he would edit the journal together with Schlick and Kurt Lewin. Carnap was in his opinion too uncritical. Cf. Ph. Frank’s memoirs in the Preface to his Modern Science and Its Philosophy, Cambridge, Mass., Harvard University Press 1949, and especially Th. Uebel, Vernunftkritik und Wissenschaft: Otto Neurath und der Erste Wiener Kreis, Springer, Wien 2000. L. Friedländer was representing Springer in Vienna and he made the agreement with Schlick and Frank, see his letters to Schlick, August 3, 1925, VCA. R.Carnap to M.Schlick, January 15, 1926, VCA. Ibid. ‘Neurath über Konstitutionstheorie’. ASP RC 029-19-03:1R. Archives of Scientific Philosophy of the Twentieth Century, University of Pittsburgh, Special Collections (=ASP). Quoted with the permission of the University of Pittsburgh. All rights reserved. Ibid. R.Carnap to M.Schlick, May 28, 1926, VCA. ASP RC 029-19-03: 1R. ASP RC 029-19-03: 1V. ASP RC 029-19-03: 1R. R. Carnap, ‘Aufforderung zur Teiinahme an Besprechungen über den Aufbau der Wirklichkeit (Strukturtheorie der Erkenntnis)’, ASP HR 102-64-02. “Gewiss können Sie das Realitätsaxiom ein metaphysisches nennen; aber ohne dieses Axiom wäre ihr Konstitutionssystem nur ein Schachspiel, und die ganze Wissenschaft auch. Einen Sinn im Sinne der Naturerkenntnis bekommt die Wissenschaft erst mit dem Realitätsaxiom. – Ich glaube also, dass Ihre Neutralität ein schöner Traum ist ...” H.Reichenbach to R.Carnap, February 20, 1927. ASP RC 102-64-02. See L. Wittgenstein, Wittgenstein’s Nachlass, The Bergen Electronic Edition, Oxford CD-ROM 2000, e.g. Item 105, pp.84-8; Item 106, p.203: Item 107, p.205. The world of data was for Wittgenstein the “primary” or “first” system with respect to the world of physics which was the “secondary” or “second” system. In the Big Typescript, Wittgenstein wrote: “Es gibt nicht – wie ich früher glaubte – eine primäre Sprache im Gegensatz zu unserer gewöhnlichen, der ‘sekundären’. Aber insofern könnte man im Gegensatz zu unserer Sprache von einer primären reden, als

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21. 22. 23. 24.

25. 26. 27.

28. 29. 30. 31.

32. 33.

34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48.

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in dieser keine Bevorzugung gewisser Phänomene vor anderen ausgedrückt sein dürfte; sie müsste sozusagen absolut sachlich sein.” Item 213, p. 488. Ph. Frank to M.Schlick, VCA. The letter is undated but the approximation “Herbst 1927” written by someone else seems reasonable. Waismann had been writing a book for the series, entitled Raumproblem und Phänomenologie; see F. Waismann to M.Schlick, September 20, 1925, VCA. But the idea of writing a book about Wittgenstein went beyond that plan. Reichenbach wrote to Schlick February 22, 1933, VCA, as follows: “Nächstens wollen wir [the Berlin Group, J.M.] auch Wittgenstein’s Traktat vornehmen.” Soon after that Reichenbach was forced to leave Germany, as is well known. O.Neurath to W. Hollitscher, November 22, 1937, in: P.Goller and G.Oberkofler, ‘Walter Hollitscher. Briefwechsel mit Otto Neurath 1934-1941’, Die Alfred Klahr Gesellschaft und ihr Archiv. Beiträge zur österreichischen Geschichte des 20. Jahrhunderts, ed. by H.Hautmann, Wien 2000, p. 184. O. Neurath and others to R.Carnap, December 31, 1927, ASP RC 029-16-06. R. Carnap to O. and O. Neurath, February 25/March 3, 1928, ASP RC 029-16-05. L. Friedländer from Vienna informed Schlick about this in May 25, 1928. But Schlick made a new attempt, now trying to persuade the Berlin head of the publisher. In November 16, 1928, F. Springer told Schlick personally that the book could not open the series. Both letters are in the VCA. R. Carnap to M. Schlick, March 20, 1927, VCA. R. Carnap’s application, April 11, 1927, VCA, and a leaflet informing Schlick about the result in the beginning of August, VCA. R. Carnap to M. Schlick, August 18, 1927, VCA. R. Carnap to M. Schlick, December 23, 1927, VCA: “Das MS ist zu 3/5 druckfertig, der Rest wird wohl auch bald fertig sein. Ich habe alles noch durchgearbeitet und überall lieber im Kleinen gekürzt, keine ganzen Abschnitte gestrichen. Das wird dem MS nur nützen, glaube ich, Freilich macht es mehr Arbeit, viele Teile müssen neu getippt werden.” R. Carnap to O. Neurath, October 7, 1928, ASP RC 029-16-01. Ibid. In his letter in January 28, 1929, Carnap was still teaching the Finnish philosopher: “Sie fügen hinzu: ‘im Sinne der ‘realistischen’ Physik; es gibt aber doch nur eine zulässige, metaphysikfreie Interpretation der Physik.” Carnap’s letters to Kaila are in Prof. G.H. von Wright’s private archive. O.Neurath, Gesammelte philosophische und methodologische Schriften, Vol. 1, ed. by R. Haller and H. Rutte, Hölder-Pichler-Tempsky, Wien 1981, p. 293. See J. Manninen, ‘Wie entstand der Physikalismus?’, Nachrichten. Forschungsstelle und Dokumentationszentrum für Österreichische Philosophie, Vol. 10, 2002. This paper gives a more detailed picture of WG1. VCA ON K.3, pp. 9-10. Ibid. Ibid., p. 22. P. Duhem, The Aim and Structure of Physical Theory, transl. by P.P. Wiener, Atheneum, New York 1981, p. 104. Ibid., p. 267. VCA ON K.3, p. 11. Ibid., p. 14. Ibid., p. 22-3. Ibid., p. 65. Cf. R. Carnap to O. Neurath, October 7, 1928, ASP RC 029-16-01. R. Carnap to M. Schlick, December 23, 1927, a separate sheet ‘Frage über die Wahl des Buchtitels’ added to the letter. The letter was the same as mentioned in note 26. R. Carnap, Der logische Aufbau der Welt, Weltkreis-Verlag, Berlin-Schlachtensee 1928, § 2, § 162 and especially § 16. Cf. also Friedman, Reconsidering, pp. 95-101. A critical analysis of Carnap’s one-domain assumption is given in J. Hintikka, ‘Carnap’s Work in the Foundations of Logic and Mathematics in a Historical Perspective’, J. Hintikka, Lingua Universalis vs.

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49. 50.

51.

52.

53. 54. 55.

56. 57.

Calculus Ratiocinator: An Ultimate Presupposition of Twentieth-Century Philosophy, Kluwer, Dordrecht 1997. Contrary to Hintikka, the one-domain assumption seems to have been an integral part of Carnap’s overall philosophical views. E. Kaila to M. Schlick, January 13, 1929, VCA. To be published in an edition of Schlick’s correspondence by R. Fabian, M. Iven and H. Rutte, Springer, Wien. ‘Gespräch mit Waismann’. ASP RC 102-76-03. Cf. R. Carnap to M. Schlick, September 28, 1932, VCA: “Ja ich weiss bis heute noch nicht, wie Wittgensteins Auffassung hier ist, da Waismann ja nicht deutlich Stellung genommen hat, sondern nur sagte, dass er (und Wittgenstein) gewisse Bedenken haben, ohne sie jedoch formulieren zu können.” More about the MS and the participants in J. Manninen, ‘Das verbotene Buch des Wiener Kreises’, in: Topos, Vol. 17, 2001, p. 65-77. Schlick’s letter to Frank, containing his motivations, is to be found among the unidentified letters of the VCA. R. Carnap to O. Neurath, July 25, 1930, ASP RC 029-14-11. Carnap’s first suggestion was that Heinrich Neider should help Neurath, but he wrote then: “Falls Neider nicht will oder kann, ware ich im äussersten Fall bereit, obwohl ich nicht soviel Zeit daran setzen könnte wie N.” R. Carnap to M.Schlick, September 28, 1932, VCA. R. Carnap to M. Schlick, August 28, 1930, VCA. See the paper mentioned in note 51. Cf. also J. Manninen, ‘Otto Neurath oder die Unmöglichkeit einer “privaten Sprache” und die Möglichkeit der Visualisierung’, J. Manninen, Feuer am Pol. Zum Aufbau der Vernunft im europäischen Norden, Peter Lang, Frankfurt am Main 1996, pp. 393-412. Cf. ‘Besprechung über Physikalismus am 4.3.1931’, VCA ON K.4, and the discussions documented in Stadler, Studien zum Wiener Kreis, p. 275 ff. Neurath formulated this in his last period by quoting Karl Popper’s view that empirical science should represent only the one real world, the world of our experience, and then he delivered his criticism: “I speak of pluri-statements and therefore I see no way how to reach THE ONE WORLD, or one preferred system of statements. ... I think that Philipp Frank fought sufficiently the one real world besides the many possible worlds. I myself and he and Duhem and Poincaré belong together, we are only more consistent than Duhem and Poincaré.” Neurath also asked: “I should like to learn from you what you say about that.” No answer was given. O. Neurath to R. Carnap, April 1, 1944, VCA.

History of Science and Ideas University of Oulu P.O. Box 1000 FIN-90014 Oulu Finland [email protected]

WOLFGANG HUEMER

LOGICAL EMPIRICISM AND PHENOMENOLOGY: FELIX KAUFMANN *

1. THE RELATION BETWEEN PHENOMENOLOGY AND ANALYTIC PHILOSOPHY

The history of philosophy of the twentieth century can be best characterized, it has been argued, by the opposition between two of its main movements, phenomenology and analytic philosophy. This strategy seems appropriate since both movements have their beginnings around the turn of the century, and most philosophical positions after the Second World War have their roots in one of the two movements. In addition, there was not much contact between the two movements, but there were exceptions. In this paper I will discuss one of the earliest attempts to actively combine the results of Husserlian phenomenology with the logical empiricism of the Vienna Circle, which was proposed by Felix Kaufmann in a number of articles he published in the early forties. In the last two or three decades an increasing number of philosophers have pointed out that there are important parallels between Husserlian phenomenology and analytic philosophy. Peter Simons, for example, states that the divide between the two traditions “did not exist at the turn of the century and only became clearly apparent after the Second World War.”1 Similarly Michael Dummett, who mentions in his History of Analytical Philosophy that to a German student of philosophy in 1903 – i.e., two years after the publication of Husserl’s Logical Investigations, where he first developed his phenomenological project – Husserl and Frege must have appeared “[n]ot, certainly, as two deeply opposed thinkers: rather as remarkably close in orientation, despite some divergence of interests.”2 In fact, there are considerable parallels in the positions of the two philosophers, who had exchanged letters and sent each other their publications as early as the 1890s. In addition, Frege reviewed Husserl’s Philosophy of Arithmetic, criticizing his project of developing a psychological foundation of logic which, in turn, was one of the factors that convinced Husserl that this project was doomed3 and to develop his critique of psychologism in the Logical Investigations, where he distinguished normative from pure logic, the latter being about ideal (logical) objects. Moreover, it was this ontological move of accepting the existence of ideal objects that allowed Husserl to further develop Franz Brentano’s method of descriptive psychology into his own phenomenological 151 F. Stadler (ed.), The Vienna Circle and Logical Empiricism: Re-evaluation and future Perspectives, 151–161. © 2003 Kluwer Academic Publishers. Printed in the Netherlands.

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method, a method that aims at describing the essential aspects of our mental acts. Hence, we could say that Frege indirectly influenced Husserl in his developing the phenomenological method. But also in Husserl’s later philosophy, there are striking parallels to Frege, as the ground-breaking work of Dagfinn Føllesdal4 shows. The exchange and the parallels between phenomenology and analytic philosophy are not limited to the work of Husserl and Frege, though. We find, for example, that there was a strong interest in the early work of Husserl among Anglo-Saxon analytic philosophers in the first two decades of the twentieth century: Russell, for example, brought Husserl’s Logical Investigations with him to prison with the intention of reviewing it for Mind – without ever fulfilling this intention. In addition, Moore and Ryle showed a great interest in Husserl’s Logical Investigations.5 I assume that their attention to Husserl stems from an interest in Franz Brentano and Bernard Bolzano, and runs parallel to an interest in Meinong’s theory of objects. In short, at the beginning of the century the two emerging traditions were rather close, and their relationship was characterized by a mutual interest in the other position. If we look at the situation some thirty years later, however, we find that things have changed dramatically. Husserl’s so-called ‘transcendental turn,’ which was first proposed in his Ideas of 1913, as well as the work of his students, mainly Martin Heidegger, have caused various analytic philosophers to become suspicious of phenomenology, a trend that is reflected in Ryle’s articles on phenomenology as well as in the debate between Schlick and Husserl: Schlick harshly criticized Husserl’s phenomenological project in the first draft of his book General Theory of Knowledge, to which Husserl reacted in the foreword to the second edition of the Logical Investigations6, which caused Schlick to revise the argument, but not the tone of his critique in the second edition. After this exchange Husserl ignores Schlick’s work, while Schlick goes on to occasionally criticize the phenomenological movement.7 This exchange between Husserl and Schlick, however, created a clear line of demarcation between the phenomenological movement and the Vienna Circle that was respected by most members of the two schools – even though there were some personal connections between the fronts: Rudolf Carnap, for example, attended Husserl’s seminars in 1924/258. It has been pointed out repeatedly that there are strong parallels between Husserl’s notion of constitution and Carnap’s constitutional system as developed in The Logical Structure of the World9. It is not clear how strong Husserl’s influence in this phase of Carnap’s work actually was10, but if there was any, it is quite obvious that it diminished drastically in later years. Carnap’s attitude towards the phenomenological movement in the thirties is well documented in his harsh attack on Heidegger in the paper The Elimination of Metaphysics Through Logical Analysis of Language, where Heidegger’s phenomenology has become the prototype of bad metaphysics.

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2. FELIX KAUFMANN

The only member of the Vienna Circle who actively tried to bridge the gap between logical empiricism and Husserlian phenomenology is Felix Kaufmann, who was an associated – but very active – member of the Vienna Circle.11 Kaufmann was primarily interested in philosophy of law and the methodological foundations of the social sciences. Originally a student of Kelsen, he soon became interested in Husserl, who had a strong influence on his work. Kaufmann contacted Husserl in the early twenties; they met various times and exchanged numerous letters.12 In their correspondence they hardly discussed philosophical problems, though. The letters are interesting mainly for historical reasons, since they document Husserl’s attempt to emigrate from Nazi-Germany to Czechoslovakia in the thirties. Husserl hoped that Kaufmann could support him in this project. Kaufmann did not always have an easy time within the Vienna Circle. Since he did not hide his interest in Husserl, he was considered a phenomenologist by the other members. Gustav Bergmann writes in his Memories of the Vienna Circle that “when they [Kaufmann and Neumann, another participant of the meetings who was interested in Husserl] took the floor, during the classical period Schlick occasionally showed a certain impatience and sometimes even interrupted the discussion outright.” l3 Bergmann adds that the situation somewhat improved when the Wittgensteinians gained more influence in the Vienna Circle since “they [the phenomenologists] claimed to recognize many of the ideas now advanced [by the Wittgensteinians] as old teaching from their own school” l4 which was, however, rejected by Schlick and Waismann. The latter, however, “in private recommended reading Husserl.” 15 This rapprochement might have somewhat improved the situation for the phenomenologists, but definitely backfired for the Wittgensteinians. “It was from this side, moreover, that criticism set in. In the Circle Hahn once asked Waismann directly how he distinguished himself any more from a phenomenologist.” 16 These remarks clearly show that being associated with Husserlian phenomenology did not improve Kaufmann’s position within the Vienna Circle. In the years when he participated at the meetings of the Vienna Circle, Kaufmann was not a professional philosopher, but worked as a manager for the Anglo-Iranian Oil Company. In 1938 he had to emigrate to the USA. He got a call to the New School for Social Research, where he taught philosophy until his death in 1949.

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3. K AUFMANN ’ S P OINTS : E IDETIC I NTUITION ANALYSIS OF SENSE-DATA

AND

After his emigration, Kaufmann somewhat lost his interest in phenomenology. He became interested in Dewey and turned more and more towards pragmatism. Shortly after arriving in New York, however, he wrote some articles in which he discussed the relationship between phenomenology and logical empiricism.17 In these articles he concentrated on two points. First, he argued that the critique of phenomenology raised by the logical empiricists of the Vienna Circle was based on a misunderstanding of Husserl’s notion of eidetic intuition (Wesensschau), which they criticized as bad metaphysics. Second, he gave a phenomenological critique of the empiricist notion of raw sense data. Let me first turn to Kaufmann’s discussion of the positivistic critique of Husserl’s notion of eidetic intuition. Kaufmann addresses the standard critique brought up against Husserlian phenomenology in the Vienna Circle, especially by Moritz Schlick – without mentioning Schlick’s name, though. We can see several main strands in this critique. Even though he advocates an empiricist position, Schlick shares Husserl’s concerns about psychologism.18 He cannot, however, accept Husserl’s solution, according to which pure logic is concerned with ideal logical objects. For Schlick this move is unacceptable, as it buys into Platonism. And, in fact, Husserl’s Logical Investigations do create the impression of having strong Platonistic tendencies, for his arguments are based on the acceptance of a ‘pure logic,’ a discipline that is concerned with ‘ideal logical objects.’ However, Schlick’s concerns do not really address Husserl’s position. As Kaufmann points out19, Husserl explicitly rejects Platonism in his later work. Moreover, even though some formulations, esp. the talk about ideal logical objects and essences, invite a Platonistic reading of the Logical Investigations, this interpretation is nonetheless a misreading and a misrepresentation of Husserl’s concerns. Husserl never explicitly advocates Platonism in the Logical Investigations. In a later text, Draft to an Introduction to the Logical Investigations of 1913 (which was only published posthumously), he complains that many readers have interpreted his text in a Platonistic way: This accusation is not at all justified; it is, rather, in stark contrast to my account and is based on exactly those historical prejudices from which I first had to liberate myself in an arduous way.20

The historical prejudices Husserl is speaking about have to do with the identification of an acceptance of pure logic with the acceptance of a Platonistic ontology, in which Husserl believed when he first read Bolzano, i.e., more than ten years before he wrote the Logical Investigations: “I mistook, however, his [i.e., Bolzano’s] original thoughts on presentations, propositions, truths ‘in them-

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selves’ to be metaphysical absurdities”21. Only by reading Lotze, Husserl states, did he realize that he was misreading Bolzano, which influenced the development of his critique of psychologism in the Prolegomena of the Logical Investigations in a decisive way. Thus, one can say that Husserl’s terminology, at least in his Logical Investigations, was not very clear, or that he should have added a few clarifying paragraphs, but not that Husserl advocates a form of Platonism in this work. Schlick’s point concerning Husserl’s alleged acceptance of Platonic essences is, however, connected to a second strand of criticism which might even apply to a non-Platonistic reading of the ‘ideal object’ theory. This critique is directed against the kind of mental act in which we are, according to Husserl, directed towards these ideal logical objects, i.e., against the intuition of essences. Schlick doubts that we are in a position to intuit abstract essences. “We ask: How in general can non-real objects – concepts or judgments – be ‘given’ to us when all that we are acquainted with as given are real contents of consciousness?”22 Somehow, Schlick continues, these non-real, ideal objects must be real contents of conscious acts – otherwise we could not have any knowledge about them. He goes on to criticize Husserl for explaining this problem by distinguishing between real and ideal evidence, the latter of which can account for our grasping ideal objects in eidetic intuition. Schlick counters that this does not solve the problem, since we could ask again how one knows about ideal evidence. This would have to be a real property of our mental acts23, and we face the same problems as before. The strategy adopted by Husserl, according to which we can acknowledge a fact only if we know it with a high degree of evidence, cannot possibly solve any problem, Schlick argues, since one must be aware of the fact that one knows with a high degree of evidence; i.e., one would need evidence for this second order knowledge, which would lead to an infinite regress. This empiricist critique of Husserlian phenomenology, Kaufmann argues, is based on a misunderstanding of Husserl’s notion of evidence. Rather than formulate an argument, Kaufmann quotes Husserl’s Formal and Transcendental Logic of 1929, a book with which Schlick was likely unfamiliar. In this quotation, Husserl talks about the sensualistic misunderstanding of the notion of evidence, i.e., the characterization of evidence as a certain form of feeling we experience in conjunction with a certain act. Husserl calls that view an absurdity and explains that evidence is not a feeling that accompanies the act, but rather an intentional accomplishment, something that does not arise from one act alone, say a perception, but rather in connection with recollections. This interplay of various partial intentions gives for the first time ‘original certainty’ in the full sense of the existence of a subjective object called a psychic datum ... something to which one can always return and which one can always recognize in reactivation as the Same.24

In short, evidence is for Husserl not a feeling that accompanies the act, but an accomplishment that makes perception of objects possible. Schlick’s critique,

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thus, stems from a misunderstanding of Husserl’s notion of evidence and a Platonistic misinterpretation of Husserl’s attack on psychologism. With these remarks, Kaufmann showed that the empiricist critique of the phenomenological notion of ‘eidetic intuition’ is not justified. Kaufmann’s second point consists in his argument that the basic assumption of logical empiricism, according to which raw sense data cannot be further analyzed, is itself a pseudo-explanation. Empiricists still do not recognize with sufficient clarity how close the kinship is between the idea of objectively given sense-data, inaccessible to further analysis, and the metaphysical ontology which they oppose.25

In this context, Kaufmann discusses Carnap’s critique of synthetic a priori statements which is based on his distinction between pure and interpreted calculus, where the former is concerned with the signs on a merely syntactical level, whereas the latter assigns meaning to these signs. According to this critique, the tendency to accept synthetic a priori statements stems from a confusion of syntactical sentences, i.e. sentences about language, on the one hand, and object sentences, i.e. sentences about objects in the narrow sense, on the other. The sentence “Every color is at a place,” is often quoted as an example of a synthetic a priori statement. According to this critique, this is a mistake that is based on a misunderstanding of what the sentence is actually about: it is misinterpreted as an object-sentence when it actually is a syntactical sentence; it is not about empirical objects in the world, but rather informs us how the words it contains are used in language. This becomes most obvious if we substitute the formal language for the object language: “Then, e.g., instead of the sentence ‘Every color is at a place,’ the sentence ‘A color-expression is always accompanied in a sentence by a place designation,’ would occur.” 26 According to this view, “the rules of a pure calculus can be described entirely within the limits of logical syntax.” 27 In consequence, there is no need for synthetic a priori statements, it is rather determined by the rules of syntax whether a certain expression can be formulated or not. When we actually use a language we have to add the semantic level; i.e., we have to interpret these signs, which can be done by giving a series of correlative definitions that state the meaning of the signs used. This meaning is determined by indicating experiences that shall constitute the sufficient condition for using the expressions in question, e.g., it is stipulated that one may use the sentence ‘A blue thing is at the place p at time t,’ on the basis of an optical perception of a certain kind.28

It is at this point that Kaufmann’s critique sets in: this analysis of Carnap’s position shows, according to Kaufmann, that the logical empiricists ascribe a role to raw sense-data which they cannot play. Carnap’s analysis presupposes that “[s]igns and formulae are given as objective, i.e., are regarded as identifiable at

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different times and by different persons.” 29 This creates a tension within the empiricist program that bases everything on raw sense data: The empiricist, however, who defines the ‘world’ in terms of possible experience and bears in mind that every experience is the experience of a particular man at a particular time, should see clearly that the presupposition of an intertemporal and intersubjective harmony of experiences – a presupposition implicit in operating with objectively given signs – is accessible to, and urgently requires, further analysis.30 Kaufmann points out that Carnap’s program presupposes that we have objective experiences and that the meaning of the words we use have their source in these experiences. What happens, however, if we ask for the meaning of “objective experience”? We are then confronted with the following situation: The meaning of ‘objective experience’ is defined in terms of certain rules of method including presuppositions concerning given fundamental meanings. These meanings in turn point back to experiences as constitutive elements. Obviously the meaning of ‘experience’ cannot be the same in both cases.31 Kaufmann argues that here we are facing two different ‘strata of experience.’ In other words, we are using the word ‘experience’ in two completely different ways. On the one hand, as we have seen above, we use it to define the meaning of other words (like blue, yellow, etc). If we try to clarify the notion of experience, on the other hand, we find that we need to make important presuppositions to use that concept. We conceive of the physical world that is experienced as being the same for every human being. The notion of human being, thus, is presupposed by the notion of objective experience, etc. On this lower stratum of experience, we ask “what presuppositions are implicit in the idea of an objective world of experience and how these experiences enter into every single experience of the individual.” 32 In consequence, the differences between phenomenology and logical empiricism may be seen as resulting from these distinct strata of experience. Both see the task of philosophy in analyzing meaning. “As far as this analysis remains within the stratum of objective meanings it is logical analysis; as far as it transcends this stratum it may be called transcendental analysis.” 33 If the logical empiricist would gain some appreciation for this distinction of various strata of experience and try to analyze the meaning of experience on the lower stratum, he learns to see that even the simplest object-perception contains a manifold of complexly interwoven anticipations of one’s own and other persons’ potential perceptions – anticipations that my be fulfilled or disappointed.34 Kaufmann argues, as this quotation shows, that the logical empiricists base their position on the notion of experience which, however, should itself be analyzed. If they would direct their attention to this basic level of their theory, and transcend the stratum of objective experience, they would appreciate the need for

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a holistic understanding of experiences. In its present form, logical empiricism accepts a metaphysical assumption that is not proven, namely that there are experiences that cannot be further analyzed. Logical empiricists, thus, have to face a critique they have brought up against phenomenology: namely, that they do bad metaphysics. Kaufmann’s argument, thus, amounts to abandoning the very project of logical empiricism – or at least adding a whole new dimension to it, since it challenges its empiricist basis. This does not mean, however, that Kaufmann’s diagnosis stands in contrast to the program of the Vienna Circle, since it is compatible with a scientific approach to philosophy and a positivistic point of view. On the contrary, if Kaufmann’s argument is right, not to reform one’s position in the way suggested and to continue holding the notion of raw sense data would amount to accepting a piece of bad metaphysics. With these two points, Kaufmann has reached his goal to show first that phenomenology and logical empiricism are not incompatible, but rather complement each other on different levels, and second that “if the logical empiricists are consistent in seeking their goal, namely, the analysis of scientific methods, then the problems that form the point of departure for phenomenological reflection must emerge within their field of vision.” 35 Thus, if the logical empiricists take their own program seriously, then sooner or later they should, according to Kaufmann, gain appreciation for the phenomenological program and possibly start doing phenomenology themselves. 4. ANALYTIC PHENOMENOLOGY

We have seen that one of the decisive reasons for the schism between phenomenology and logical empiricism was – apart from the differences in their positions which were not that insuperable after all – the debate and the resulting personal antagonism between Schlick and Husserl. This mutual opposition continued after the death of its proponents, when most of the members of the Vienna Circle – unlike some of the prominent proponents of the phenomenological movement – had to emigrate from Europe. In North-America, Schlick’s article “Is There a Factual A Priori,” 36 where he criticizes the phenomenological notion of the ‘synthetic a priori,’ was anthologized in Feigl’s and Sellars’ book Readings in Analytic Philosophy, and so created a bad press for phenomenology among a younger generation of Anglo-North-American analytic philosophers. Kaufmann’s article, on the other hand, was published in a book that was only interesting to North American phenomenologists, and thus escaped the attention of philosophers interested in logical empiricism. It is noteworthy, however, that with his critique Kaufmann points his finger at that weak point of logical empiricism that was aimed at also by Wilfrid Sellars’ attack on the Myth of the Given 37. Kaufmann, thus, uses Husserlian phenomenology to criticize an assumption of logical empiricism that also has

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been criticized from within, and therefore in a way that could be more easily accepted by the logical empiricists. The original and valuable aspect of Kaufmann’s critique is, however, that he does give a case study of how one can combine the results of Husserlian phenomenology with the method of analytic philosophy. His intention is not to make a historical point on the question of whether the two movements are compatible or not or what they have in common and where their disagreements are, but rather to develop a new methodological standpoint that makes it possible to address and resolve actual philosophical problems. With this strategy, Kaufmann’s position is still today an important example not only of how to deal with competing positions in philosophy, but also of how to approach a field that could best be characterized as analytic phenomenology.

N OTES *

I would like to thank Johannes Brandl, Tommaso Piazza, and Christian Beyer for their helpful comments on an earlier draft of this paper.

1.

Peter Simons, Philosophy and Logic in Central Europe from Bolzano to Tarski. Dordrecht: Kluwer, 1992, p. 2. Michael Dummett, Origins of Analytical Philosophy. Cambridge: Harvard University Press, 1993, p. 26. Husserl was also strongly influenced by Bolzano and Lotze. In a conversation with Boyce Gibson he states that Frege’s critique “hit the nail on the head.” (qtd. in Dagfinn Føllesdal, “Response by Dagfin Føllesdal”, in: H. Dreyfus and H. Hall (Eds.), Husserl, Intentionality. and Cognitive Science. Cambridge: M.I.T. Press, 1982, 52-56, p. 55). Cf. Dagfinn Føllesdal, “Husserl’s Notion of Noema” In: Journal of Philosophy 66, 1969, 681687. For a discussion of the reception of Husserlian phenomenology among British philosophers, cf. Mathieu Marion “Les Recherches Logiques et le réalisme britannique” (2001, forthcoming). Cf. Edmund Husserl, Logische Untersuchungen. Husserliana XIX/2. Dordrecht, Kluwer, 1984, p.535f. Husserl complains about Schlick’s superficiality and lack of precision, but misquotes the German title of Schlick’s book Allgemeine Erkenntnislehre: “Wie bequem es sich manche Autoren mit wegwerfenden Kritiken machen, mit welcher Gewissenhaftigkeit sie lesen, welchen Unsinn sie mir und der Phänomenologie zuzumuten die Kühnheit haben, das zeigt die Allgemeine Erkenntnistheorie [sic!] von Moritz Schlick.” For the relationship between Schlick and Husserl, cf. M.M. Van de Pitte, “Schlick’s Critique of Phenomenological Propositions”, in: Philosophy and Phenomenological Research 45, 1984, 195-225; Jim Shelton, “Schlick and Husserl on the Foundations of Phenomenology”, in: Philosophy and Phenomenological Research 48, 1988, 557-561; or Roger Schmit, “Moritz Schlick und Edmund Husserl. Zur Phänomenologiekritik in der frühen Philosophie Schlicks”, in: Grazer Philosophische Studien 58/59, 2000, 223-244, who argues that Schlick developed his own position by contrasting it with Husserl’s. Cf. Rudolf Bernet, Iso Kern, and Eduard Marbach, An Introduction to Husserlian Phenomenology. Evanston: Northwestern University Press, 1993, p.221 and Karl Schuhmann, Husserl Chronik: Denk- und Lebensweg Edmund Husserls. Den Haag, Nijhoff, 1977, p. 281. Cf. Guido Küng, “The Phenomenological Reduction as Epoche and as Explication,” in: The Monist 52, 63-80; Verena Mayer, “Die Konstruktion der Erfahrungswelt: Carnap und Husserl” In: Erkenntnis 35, 287-303; Tommaso Piazza, “Fenomenologia nell’ Aufbau? Carnap, Husserl e la costituzione del mondo”, to appear in: Lanfredini, Roberta (Ed.) Forma e contenuto. Milano:

2. 3.

4. 5. 6.

7.

8.

9.

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10. 11. 12. 13.

14. 15. 16. 17.

18.

19. 20.

21. 22. 23.

24.

25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36.

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LED, 2002; or Wolfgang Huemer, “Husserl and Haugeland on Constitution,” in: Synthese (forthcoming). Verena Mayer conjectures that Carnap’s book might be a revised version of a draft that could have had more references to Husserl in a first draft, which, however, might have been deleted under the influence of Schlick. (Cf. Meyer, op. cit., 301, fn. 11). Cf. Friedrich Stadler, Studien zum Wiener Kreis, Frankfurt: Suhrkamp, 1997, esp. p.712ff as well as chapters 6 and 7. These letters are reprinted in: Edmund Husserl, Briefwechsel. Band IV: Die Freiburger Schüler. K. und E.Schuhmann (Ed.). Dordrecht: Kluwer, 1994. Gustav Bergmann, “Memories of the Vienna Circle. Letter to Otto Neurath (1938)”, in: Friedrich Stadler (Ed.), Scientific Philosophy: Origins and Development. Vienna Circle Institute Yearbook 1. Dordrecht: Kluwer, 1993, 193-208, p. 200. Ibid. Ibid. Ibid. Cf. Felix Kaufmann, “Phenomenology and Logical Empiricism”, in: Marvin Farber (Ed.), Philosophical Essays in Memory of Edmund Husserl. Cambridge: Harvard University Press, 1940, 124-142 and his “Strata of Experience”, in: Philosophy and Phenomenological Research 1, 1941, pp. 313-324. He does, however, express the assumption that psychologism might only be the result of imprecise formulations: “...they must surely have had some inkling of the fact that a concept is not a reality of consciousness but, as it were, an unreal fiction.” (Moritz Schlick, General Theory of Knowledge. Transl. by Albert Blumberg. Wien/New York: Springer, 1974, p. 134) Cf. Kaufmann “Phenomenology and Logical Empiricism”, op. cit., p. 135. Edmund Husserl, “Entwurf einer ‘Vorrede’ zu den ‘Logischen Untersuchungen’”, in: Tijdschrift voor filosofie 1, 1939, 106-133 and 319-339, p. 118. My translation. “Dieser Vorwurf ist völlig unberechtigt, er steht mit dem Inhalt meiner Darstellungen in schärfstem Widerspruch und beruht auf der Übermacht eben der historischen Vorurteile, von denen ich mich einst mühsam losringen musste.” Husserl, Entwurf einer ‘Vorrede’, op. cit, p. 129. My translation. “Seine originellen Gedanken über Vorstellungen, Sätze, Wahrheiten ‘an sich’ missdeutete ich aber als metaphysische Absurditäten.” Moritz Schlick, General Theory of Knowledge, op. cit., p. 139. Cf. Moritz Schlick, General Theory of Knowledge, op. cit., p. 141: “How do we know anything about an ideal self-evidence or about its possibility? Its existence must make itself known realiter in some way in our consciousness, through a feeling of self-evidence or some other phase of mental reality. And then all the earlier objections are revived, and everything remains as it was before: the problem pursues us no matter how often we seek to elude it by some twist or turn.” Edmund Husserl, Formal and Transcendental Logic. Husserliana XII. Dordrecht, Kluwer, 1970, p. 166; quoted in: Felix Kaufmann, “Phenomenology and Logical Empiricism”, op. cit., 136. Felix Kaufmann, “Phenomenology and Logical Empiricism”, op. cit., p. 131. Ibid., p. 129. Ibid. Ibid. Ibid, p.131. Ibid. Felix Kaufmann, “Strata of Experience”, op. cit., p. 322. Felix Kaufmann, “Phenomenology and Logical Empiricism”, op. cit., p. 132. Felix Kaufmann, “Strata of Experience”, op. cit., p. 322. Felix Kaufmann, “Phenomenology and Logical Empiricism”, op. cit., p. 132. Ibid, p. 125. Moritz Schlick, “Is There a Factual a Priori?” in: Herbert Feigl and Wilfrid Sellars (Eds.): Readings in Philosophical Analysis. New York : Appleton, 1949, 277-285.

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37. Cf. Wilfrid Sellars, “Empiricism and the Philosophy of Mind”, in: Herbert Feigl and Michael

Scriven (Eds.) Minnesota Studies in the Philosophy of Science, vol. 1. Minneapolis: University of Minnesota Press, 1956, pp. 253-329.

Department of Philosophy Universität Erfurt Germany [email protected]

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ARTUR KOTERSKI

BÉLA VON JUHOS AND THE CONCEPT OF “KONSTATIERUNGEN” Béla von Juhos took part in the famous protocol sentences debate. He tried to defend and develop Schlick’s conception of Konstatierungen. Juhos became one of the staunchest critics of physicalism, arguing against Carnap, Neurath and Hempel. Like Schlick, he thought the so-called left wing of the Circle had abandoned empiricism when they rejected comparison of ‘facts’ and propositions as Verdopplung. On an another philosophical front he fought against Ayer who, similarly to Juhos, claimed that one can compare propositions with facts, but disagreed with Schlick’s and Juhos’ idea of the incorrigibility of Konstatierungen. Juhos tried to show that the very grammar of those K-statements makes them certain and incorrigible. Here, Juhos’ ideas are very similar to those of Schlick; because of that he is often ignored as a non-interesting case of another uncritical follower. This is not true, and this paper tries to trace the differences between Schlick’s and Juhos’ conceptions of Konstatierungen. 1. THE ORIGIN OF KONSTATIERUNGEN

Béla von Juhos was Moritz Schlick’s student and disciple; his papers on the empirical basis problem are deeply embedded in Schlick’s theory of Konstatierungen. The story of Konstatierungen starts with the first book Schlick wrote, Allgemeine Erkenntnislehre (1918). Though we will not find this concept itself there, we do find something else, namely ‘fundamental judgments’: [...] propositions in the system of judgments by virtue of which the system rests directly on real facts we may call fundamental judgments 1 .

Schlick divides fundamental judgments into two groups: “[...] definitions, in the narrower sense, and historical judgments.” This requires some additional explanation. Definitions seem to be deictive definitions. Historical judgments are descriptive sentences about directly perceived states of affairs. All the remaining propositions in science are hypothetical. Fifteen years later he argued that: 163 F. Stadler (ed.), The Vienna Circle and Logical Empiricism: Re-evaluation and Future Perspectives, 163–169. © 2003 Kluwer Academic Publishers. Printed in the Netherlands.

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What was originally meant by “protocol sentences”, as the name indicates, are those statements which express the facts with absolute simplicity, without any moulding, alteration or addition [...] 2 .

If protocols were to be really clear, he would finally have to leave out historical judgments. Why? Because, as soon as you write them down, you cannot separate them from the hypothetical part of knowledge. This is precisely the doctrine of Konstatierungen, even if in a nutshell. Accordingly, let’s jump to his later paper to see it in detail. 2. SCHLICK’S VERSION OF KONSTATIERUNGEN

Moritz Schlick’s conception of Konstatierungen was a counter-proposal to the physicalistic conception of ‘protocol’ or ‘basic’ statements. He tried to show that Neurath’s proposal was throwing empiricism abroad. The particular theses of Neurath’s theory so strongly disliked by Schlick were the following: 1) All sentences are hypothetical. To be a genuine sentence is to be hypothetical. 2) The truth of any p consists (if anything) in consistency with the accepted body of statements. The very word ‘truth’ is a metaphysical anachronism. And if we use it at all, we only chose to do so for our convenience in speaking. 3) Statements are compared only with statements. Anything else is just sinnlos. 4) One should not talk about ‘reality’, as it is Verdopplung, i.e. doubling metaphysics. His reasons are following: 1) Even if all scientific statements are hypotheses, there must be a link between the scientific model and the world that is modeled. No such solid link – no empiricism. 2) To cultivate science we need an unambiguous criterion of truth, not truth on decision. 3) With physicalism you cannot distinguish real science from fictitious systems. Being able to do so requires having the link that lets us compare sentences with reality. 4) It is natural to talk about the link with reality, and it is constituted by Konstatierungen. But what exactly is a Konstatierung? It is not easy to say. It is something of the form “So-and-so here now” plus – more crucially – the appropriate gesture; for example “Blue patch here now” (when, let us say, the speaker’s finger points at that patch). This looks like an observational statement and from time to time Schlick used such a term. What is peculiar to Konstatierungen?

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We can again put it into four steps:

1) Konstatierungen (K for short) are observational sentences, outside of the system-language (i.e. scientific language), so they do not have to be hypothetical. And they are not. Thus we have a solid base: incorrigible observational statements. 2) As we have this kind of Archimedean point for science, we have the genuine criterion of truth: the sentence is true if it is – by the medium of K – in agreement with reality. We cannot decide for reality. 3) Again, agreement with reality shows us which self-consistent system is the real science. Thus Konstatierungen enable our actions in the world. 4) We know that K are true, because we directly compare them with reality, because we do verify them – “we make them true”.

As one can see, the most important feature of this type of observational sentences is their incorrigibility – they are certain. This is quite an expensive feature, because you have to: a) put K outside of science: You have to, because to keep them certain you need to say that they are timeless. So, simply put, you cannot write them down, as during the process of writing they become hypothetical. b) Then you have sentences that cannot be uttered or written down – especially since when you state them (this seems a bit ironic!) you have to add a gesture, and this surely cannot be written down. c) In 1933, you had to talk about truth and about comparing sentences with reality without a good theory to support you. Schlick did not solve these problems: a) How can there be any process in the physical world which is timeless? As Neurath all too often noticed, it is a metaphysical idea. b) How is K a synthetic statement when you cannot revise it? It is not empirical. c) How can K be a statement, when you cannot say it? Not only are they outside of science but they are something pre-linguistic. d) How do you compare a sentence with reality? e) If K are of any use for science, they should be intersubjectively testable. But how is intersubjective verification of K possible? Let’s have a look at how Juhos deals with them. 3. JUHOS’ VERSION

When you look for differences between Schlick’s and Juhos’ conceptions, they are quite hard to find. What you see prima facie is that when Schlick talks about

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Konstatierungen, Juhos talks about K-sentences. But, of course, that’s too simple. Juhos wanted to defend the basic idea of Konstatierungen, but at the same time to avoid the unpleasant consequences we know from Schlick’s case. The basic idea of K-Sätze is – to repeat – that there are some privileged sentences that have empirical content, but are not hypothetical. Are K-sentences genuine sentences? K-sentences are like “I feel pain”, “I see blue here now”. This is very reminiscent of Schlick’s concept, but what is really important is that there is no gesture! Can we write down K, then? According to Juhos, yes. Then it cannot be timeless. And it isn’t. But how can he dismiss the argument that, when you say or write anything, you may forget what was at the very beginning or that, in the blink of an eye, the letters change their positions, so that in the end you say or write something completely different? Alas, there is no really good answer to be found in Juhos’ papers. He would probably have said that when you forget what was at the beginning, it is an error in action, not the kind you make when you (do not) understand a K-sentence. When you understand K, you truly know whether it is true or false. Note that K may be false, which was not the case with Schlick. So when I say I see a red patch now while I do not see it, I know that it is false. Cases where somebody says – as a slip of the tongue – “it is red” instead of “it is green” he described as trivial. As errors in action. (By the way: if it is not an error in action, i.e. when looking at the white wall you say “I see a red wall”, you have a false K.) This is another difference with Schlick. He would not say it is an error. For him, that would be another true K! So we can say that Konstatierungen are genuine sentences, that they are not timeless and that they can be written down. And they can be true or false, like any other real statement. But if they are genuine sentences, can we use them in science? Are K-sentences scientific? Juhos’ Konstatierungen are real, though, for sure, not physicalistic statements, and cannot be translated into thing-language, even if it is true that one can deduce from the system-language a sentence that looks identical to the given K. But they are not the same, as the method of obtaining them is different: in the case of K it is direct – in the case of the K-mirror it is indirect. So Juhos says exactly what his teacher taught him: K are outside of the system. Are they useless to science? Neurath would say that, because K are not intersubjectively controllable, they are of no use at all. Not only can Robinson not

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understand Friday, but he is not able to understand his own diary. To put it more strongly: K is verifiable only for its owner (and only for an infinitely short moment). If K are not verifiable for others, then these others cannot understand them. K are not only useless, but also have no meaning. Juhos’ answer was – and again it is different from Schlick’s standpoint – that K are unverifiable only in a technical or practical way. According to him, it is in principle possible to verify K. So they cannot be meaningless, as it is the logical – and not the technical – possibility of verification that decides if a sentences has meaning. Here is an example given by Juhos: There are two persons, S and B (a blind man). Let say that B perceives the sensation of blue any time S sees something blue. So B is able to test K of S in a direct, i.e. non-behaviouristic way. To answer the question on the scientific status of K we may state as follows. They are not in the system language. But physicalism is false, and the system language is not the only one. There are also other types of sentences, and to properly describe some types of phenomena you have to use them. So they are indispensable to science. Schlick also thinks so. But for the founder of the Vienna Circle, they have only a verifying function. For Juhos they describe in an unquestionable way the states of affairs that cannot be described in physical language. Are K really certain? If K describe states of affairs, if they are not timeless, are they really certain? How do we know that K are certain – how do we verify them? Schlick wrote that there are two procedures involved in the verification of a hypothesis. First, you have to understand it, i.e. to know its observational consequences or the method of its verification. Then you apply this method to check the truth value of your hypothesis. You can know the former and not know the later. But in the case of K these two processes coincide, so you have only one: when you understand K, you already know that it is true. And there cannot be any doubt about it. According to Schlick, it is meaningless to say: “I am not sure if I feel pain now” or “It is quite probable that I feel pain now”. Juhos accepted this view but he put more stress on K’s grammar; it is the grammar of Konstatierungen that secures their certainty. When we verify any hypothesis we have to check other sentences. And the truth value of this hypothesis depends on the truth value of those sentences. So, any hypothesis is a truth function of other sentences. When we know the truth value of those sentences, we know whether the hypothesis is true. If K is not hypothetical, then it cannot be a truth function of other sentences. But then there cannot be sentences such that knowledge of their truth value teaches us about the truth value of K. This also means that any two K cannot contradict each other.

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But what happens if we negate K? According to the logic we use every day, when we know that p is true, we also know that not-p is false and vice versa. So not-K is a truth function and is hypothetical. It seems that the negation of K was a problem for Juhos’ theory. First, he wrote that negated K is not K anymore. Then, when he tried to show the privileged status of K, he wrote that they are not negated in the way the hypotheses are negated. According to him, when you make a conjunction of a hypothetical sentence and its negation, you obtain something called a complete contradiction. The only way to solve it is to cancel one of them in a purely arbitrary way. But when you have a conjunction of K and not-K you have a contradiction that is incomplete. Why is it incomplete? To know that not-K (e.g. “This is not green”) is true you need some additional sentence (like “This is blue”). So the negation of K is not a truth function of only one variable. Thus when you know only that K is true, you do not know that not-p is false at the same time. After a short discussion with Ayer he abandoned both theses. Juhos agreed that K can be negated like any other sentence and he stated that the negated K is still K. What he defended until the very end was the incorrigibility of K.

Are K really incorrigible? This question may look redundant, as we have already talked about K being certain. But remember Neurath’s example of Kalon. Kalon is a gifted scientist and he is able to write with two hands at the same time. So with his left hand he writes that ‘Kalon states that there is a table in the room and Kalon can see it’, and with his right one that ‘Kalon states that the room is empty’. If they are incorrigible we have to accept both of them, which is not too comfortable. First, Juhos played a trick with negation. Negated K is not a function of only one variable. So to cancel the contradiction, we have to fill the gaps. There will be no contradiction if we say that with his left hand Kalon described what he saw in a room A, and with his right hand what he saw in the other one, room B. Even if he had not dropped this idea of intuitionistic negation, he would have had serious problems, as Kalon can make his statements precise. (Nota bene, he could have just said that one of Kalon’s K is true while the second is false – but it seems he did not notice this possibility.) So, finally, can we can cancel K? No. To defend this expensive feature Juhos explicitly wrote that you cannot correct your K, because it is not the outcome of your mistake, so there is nothing to correct. We make corrections only when we make mistakes.3

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4. CONCLUSION

To avoid pitfalls, Juhos rejected the idea that some processes are timeless, so the act of “obtaining K” must take time; it’s clear then that one can utter or write down any K – they are not designed as pre-linguistic entities. Because they have many features of ordinary hypotheses – they are intersubjectively testable (i.e. verifiable), they are accepted on empirical grounds (and let us assume that Juhos explained it appropriately) – there is still one question pending: how it is possible that one cannot revise them? Juhos thought that they cannot be subject to correction, and this thesis is the last (though the most important) link with Schlick’s doctrine. In the end he repeats what we already know from his mentor: Konstatierungen do not appear as the effect of mistakes, so there is nothing to correct in them. They are incorrigible because of their nature. Then we have again the old question about the possibility of such sentences. Having thus gone in a big circle – just to avoid pitfalls – Juhos came back to the point of departure. That is why we may say that it seems Juhos was not successful in rescuing Konstatierungen as descriptions of reality that are absolutely certain.

NOTES 1. M. Schlick, The General Theory of Knowledge, Library of Exact Philosophy, Vol. 11, Wien– 2. 3.

New York: Springer-Verlag, 1974, p. 78. M. Schlick, “Über das Fundament der Erkenntnis”, Erkenntnis, Bd. IV (1934), p. 79. Carnap was very disappointed when he read Juhos’ manuscript of “Empirische Sätze und Logische Konstanten” (later published in The Journal of Unified Science (Erkenntnis), Vol. VIII (1939/1940), pp. 354-360). In a letter to Neurath he expressed his highly negative opinion of Juhos’ work: “Juhos makes [...] formal mistakes; after I pointed to errors in an earlier MS and earlier conception, I regret now I was his teacher” (Carnap to Neurath, 18.04.1939 [ASP(RC) 102-53-31]). Quoted by permission of the University of Pittsburgh. All Rights reserved.

Department of Logic and Methodology Faculty of Philosophy and Sociology Maria Curie-Sklodowska University Pl. MCS 4, 20-031 Lublin Poland [email protected]

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PAOLO MANCOSU MATHIEU MARION

WITTGENSTEIN’S CONSTRUCTIVIZATION OF EULER’S PROOF OF THE INFINITY OF PRIMES

Es war eben auch hier die Hand eines Schleifers notwendig, um den Glanz der Edelsteine Eulers voll herauszuarbeiten. L. Kronecker

1. INTRODUCTION Ever since Georg Kreisel ended his review of Wittgenstein’s Remarks on the Foundations of Mathematics (1956) by saying that “it seems to me to be a surprisingly insignificant product of a sparkling mind” (1959, 158) there has been a strong presumption that Wittgenstein did not know much about mathematics in general and about issues pertaining to the foundations of mathematics in particular, and that his remarks on these topics were marred by this lack of proficiency in mathematical matters. One may indeed ask how much mathematics did Wittgenstein know or, in other words, how much mathematics was he able to do? For a long time, it has been generally believed that Wittgenstein held a peculiar foundational stance, ‘strict finitism’. This is certainly not the case today. Indeed, one would nowadays tend to approve of Gordon Baker and Peter Hacker, when they write that “his philosophy of mathematics does not defend a form of ‘strict finitism’, depsychologized ‘intuitionism’ or ‘constructivism’” and his purpose was “not to take sides in the debates between rival schools of mathematicians, but rather to question the presuppositions which provided the framework of their debates” (1985, 345). We will discuss a mathematical proof found in Wittgenstein’s Nachlaß, a constructive version of Euler’s proof of the infinity of prime numbers. Although it does not amount to much, this proof allows us to see that Wittgenstein had at least some mathematical skills. At the very least, the proof shows that Wittgenstein was concerned with mathematical practice and it also gives further evidence in support of the claim that, after all, he held a constructivist stance, at least during the transitional period of his thought (1929-1933).

171 F. Stadler (ed.), The Vienna Circle and Logical Empiricism: Re-evaluation and Future Perspectives, 171–188. © 2003 Kluwer Academic Publishers. Printed in the Netherlands.

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2. BEHMANN, KAUFMANN, AND WITTGENSTEIN

On October 24, 1930, Heinrich Behmann, a student of Hilbert at Göttingen then teaching mathematics at the University of Wittenberg-Halle, 1 submitted a paper to Mathematische Annalen entitled ‘Zur Frage der Konstruktivität von Beweisen’ (1930). Behmann visited Vienna from the 9th to the 20th of September, 1930, to deliver a talk for Schlick’s circle. During his stay he learned about a conjecture by the Viennese philosopher, Felix Kaufmann, according to which, roughly, all existence theorems of classical mathematics which do not rely on non-constructive existential axioms, such as the axiom of choice, are in effect constructive existence theorems. In other words, it was conjectured by Kaufmann that one should be able to show that all such existence theorems rely on an implicit exhibition of an instance. Kaufmann had made the conjecture in a book that had appeared in the spring of 1930, Das Unendliche in der Mathematik und seine Ausschaltung (1930, 66-7; 1978, 57-8).2 In his paper, Behmann proposed a ‘proof of this conjecture. Criticisms from Paul Bernays, who was at the time an assistant-editor for the Annalen, and from Kurt Gödel forced him to withdraw his paper, which remained unpublished. In its first section, entitled “A Conjecture by Kaufmann”, Behmann presents three constructivist restrictions on methods of proofs (and, consequently, on admissible theorems): (1) Elimination of non-constructive existential axioms (in particular the axiom of choice)

(2) Elimination of non-predicative existential proofs (in so far as they are not already excluded by (1)) (3) Elimination of concepts of higher type (that is, restriction to the so-called “restricted functional calculus”)3

(The use of the expression “non-predicative” in (2) was an oversight on Behmann’s part; it should read “non-constructive”.) There is no point in discussing here restriction (3), as it does not bear on the topic of this paper. Behmann clearly was of the opinion that restriction (1) is a genuine one, i.e., there are indeed theorems of classical mathematics that cannot be proved without use of the axiom of choice. Now, restriction (2) would also be a genuine restriction if there were indirect existential proofs (i.e., proofs by contradiction or reductio ad absurdum) that cannot be turned into direct ones or if there were proofs of existential claims which, although not relying on non-constructive existential axioms, can only be proved by contradiction. Kaufmann’s conjecture is to the effect that this is not the case, in other words that all indirect existential proofs satisfying (1) are also constructive. As Behmann put it in his paper: Mr. Kaufmann has recently formulated an interesting conjecture [...] He is of the opinion that an indirect proof, in so far as it satisfies condition (1), is also in essence constructive, more precisely, that it relies on a hidden instance, which through an appropriate analysis of 4 the demonstration can automatically be made explicit.

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The truth of Kaufmann’s conjecture would have implied that existential proofs of classical mathematics that do not rely on non-constructive existential axioms, would implicitly satisfy the requirement of constructivity. This, in turn, would imply that the requirement of constructivity would not entail a restriction of current mathematics. Although Kaufmann shared Brouwer’s rejection of (non-denumerable parts of) set theory, he believed that classical mathematics was already constructive and therefore that the elimination of the non-denumerable infinite would leave “mathematics as it is”, so to speak. Gödel himself provided within a few days a counterexample that refuted Behmann’s claim that he had proved Kaufmann’s conjecture.5 (However, Gödel’s objection to Behmann’s proof does not use his incompleteness theorems.) Nevertheless, Behmann’s unpublished typescript is interesting for a number of reasons. In it, he presented a general method by means of which one could turn, allegedly, a non-constructive existence proof into a constructive one. The techniques used for the proof involve one of the earliest uses of graph-theoretical and topological considerations in the study of proofs.6 Behmann’s method can also be seen as related to proof-theoretical methods developed later by Hilbert & Bernays, Herbrand, and Kreisel. Of peculiar interest to us here, however, is the fact that Behmann presented, in the last section of his paper, an application of his method to the constructivization of a well-known existence proof presented by Leonhard Euler in his Introductio in analysin infinitorum (1748, I, 235). There exist many proofs of the infinity of prime numbers,7 starting with Euclid’s famous proof.8 Euler proved the theorem by reductio ad absurdum relying on the equation:

where ranges over primes.9 The left-hand side is the harmonic series. Euler had proved that it diverges, i.e., one can say that the sum is infinite. Euler’s proof works as follows: assume ..., are all the prime numbers. From the equation

one obtains

Thus, is finite, which is a contradiction.10 However, as Leopold Kronecker pointed out in his Vorlesungen über Zahlentheorie (1901, 270), equation (A) is actually invalid; he rectified Euler’s proof

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using:

for z > 1. If there were only a finite number of primes the product would remain finite as z approaches 1, while the sum increases indefinitely. Kronecker also showed how to define an interval from to in the left-hand sum, of which it is shown that it contains at least one prime, however great is taken (1901, 270-71), thus providing a constructive addition to Euler’s proof. In this connection he made a very important remark: This proof, as Euclid’s proof, can also be cast in a form which yields an interval that contains a new prime number no matter how big is. Only then is the last and highest requirement satisfied which has to be imposed on a rigorous mathematical proof.11

Euler’s proof is of great importance for results about the infinity of primes in general arithmetical progressions, e.g., for Dirichlet’s theorem for with and relatively prime.12 The constructivization of Euler’s proof is thus far from being a mere exercise for idle minds. At all events, what is of specific interest to us, however, is the fact that, in a footnote right at the beginning of the section of his paper dealing with the constructivization of Euler’s proof, Behmann wrote: I simultaneously learned about a transformation [Überführung] of this proof into a constructive form by Mr. Wittgenstein and about Kaufmann’s conjecture.13

The attribution of a proof to Wittgenstein is quite an astounding claim and we should like to look closely into it. As it turns out, even this application of Behmann’s method to Euler’s proof is not satisfactory, but it remains of interest to us because of the light it sheds on Wittgenstein’s thinking about mathematics. On October 6, before submitting his paper, Behmann had therefore written to Kaufmann: Since I have no memory of the details of Wittgenstein’s completion of Euler’s proof that Mr. Waismann had presented, I would very much like to find out to which degree my transformation [Umwandlung] of the proof, which I worked out independently on the basis of the general scheme that I developed, corresponds to Wittgenstein’s. At any rate, it would be necessary to reach an agreement with Mr. Wittgenstein, when I shall have to mention this point, which, for reasons of fairness, can hardly be ignored; it seems best to do it through the mediation of Mr. Waismann.14

Answering Behmann’s request, Kaufmann wrote reassuringly on the 12th that: Concerning the proof that you have given as an example of your general theorem and that of Wittgenstein, Mr. Waismann considers that they are indeed related but that your footnote appropriately deals with the relationship between them, all the more so since this result is of fundamental importance to your general considerations. He does not consider himself, however, to be in a position to reach a final decision on this point and will, in accordance to your request, forward your proof to Wittgenstein and inform him about its circumstances. At all events, there is no reason to delay publication. Perhaps I should ask you to modify your

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note to the effect that you had learned about Wittgenstein’s transformation [Überführung] into a constructive form of Euler’s proof about prime numbers prior to devising your own constructivization of the proof, while not mentioning in this context that you had previously learned about my conjecture, since the latter is already in my book.15

As a result of Kaufmann’s request, Behmann reworded the footnote as follows in the final version of his paper: The fact that I recently learned about a transformation into a constructive form of this proof by Mr. Wittgenstein motivated me to devise the general procedure that I described above. Kronecker had already given in his Vorlesungen über Zahlentheorie a constructive completion (not, however, a transformation [Umformung]) of Euler’s proof.16

One may infer from these quotations that Behmann learned about Kaufmann’s conjecture and Wittgenstein’s proof during his short stay in Vienna and that he learned about the latter talking to Waismann. It does not seem that Wittgenstein actually took part in any discussions involving Behmann, Kaufmann and Waismann; the latter seems to have acted as a go-between. It is also certainly clearly implied that Wittgenstein had his own constructive version of Euler’s proof, which closely resembled Behmann’s. This evidence prompted a search for Wittgenstein’s proof. The section on ‘Euler’s Proof’ which is printed in Philosophical Grammar (1974, 383-386) does not contain a proof but it ends with some calculations that are hard to interpret at first blush. The book Philosophical Grammar was edited by one of Wittgenstein’s literary executors, Rush Rhees, who used as a basis the so-called Big Typescript, which is a voluminous typescript of 768 pages produced by Wittgenstein in 1933. Anthony Kenny (1984) has shown the extent of Rhees’ editorial intervention but a comparison of the section on Euler’s proof with the corresponding section in the recently published Big Typescript (2000, 427-9) shows that they are virtually similar. However, most of the remarks that form the Big Typescript originated in manuscripts for the years 1929-31 that are by now published as the first five volumes of the Wiener Ausgabe. It turns out that the remarks that form the section on Euler’s proof in the Big Typescript and the Philosophical Grammar originated in one of these manuscripts, namely MS 108, which is entitled ‘IV. Philosophische Betrachtungen’,17 and can be dated from the summer and autumn of 1930 – therefore around the time of Behmann’s visit to Vienna. 18 In this manuscript, now published as part of volume 2 of the Wiener Ausgabe (1994), 19 the strange calculations that end the section on Euler’s proof are continued and one can actually see the point of these, as it is clear that Wittgenstein is calculating a bound below which one can find a new prime number greater than all the elements of any given set of primes , . . . , thus providing a constructivization of Euler’s proof. It appears that both Wittgenstein and Behmann used as a point of departure Euler’s original proof, based on the invalid equation (A) and not the corrected version provided by Kronecker, although Behmann learned about it at one stage,20 since he mentions it in the footnote that we already quoted. It is unlikely that either of them used Euler’s original version but it is impossible to tell from which

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presentation of the proof they worked. We shall now look at both proofs. 3. THE TRANSFORMATION OF EULER’S PROOF IN BEHMANN Behmann starts from Euler’s invalid equation:

Assuming that (B) the number of primes is finite, say

,...,

, one obtains that

This implies (D) that is finite, which is a contradiction, since Euler has already shown that the harmonic series diverges. One should notice that the last equality of (C) is justified by the unique factorization theorem. That is every must be obtained from the previous product. By uniqueness each will only appear once. The above proof is non-constructive since it does not tell us how to find the next prime beyond Behmann’s project was to show that, by a transformation of the proof into a direct one, one could extract a bound for finding another prime number not contained in , . . . , . Although we will not present Behmann’s general strategy in detail, the following outline should suffice to get the gist of the transformation. According to Behmann’s own conventions the proof could be schematised thus:

One can, for ease, read the arrows as indicating implications. According to Behmann’s strategy we obtain a direct proof by using the negation of D and reversing the arrows of implication from D to C and also negating C and reversing the arrow of implication from C to B. In short the direct proof would look as follows:

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One should note here that states that there are infinitely many primes. Thus, the direct proof of the result of the infinitude of prime numbers would proceed in three steps: from the fact that the harmonic series diverges and equation (A) one would obtain

And, therefore, there exist infinitely many prime numbers However, this single transformation does still not give us the required instance for the existential. For this reason, Behmann claims that this information must be hidden in the statement that diverges. Indeed, the statement can be re-expressed as saying that

This, says Behmann can be shown easily by rewriting the harmonic series as

and noticing that each expression in parenthesis is > The fact that every real number can be majorized through the addition of sufficiently many sums of which the first is 1, the second and all the others greater than , can easily be shown by choosing the number of summands to be This will certainly suffice for (Here, gives the greatest natural number smaller or equal to .) We thus need to sum up members of the transformed harmonic series to go beyond or, what amounts to the same thing, 21 elements of the original harmonic series, (i.e. choose In this way one obtains a general proof of

In turn, by substituting the product

(denoted by

for

one obtains

The proof is concluded by noticing that the right-hand side

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of the inequality with finitely many summands must contain at least one summand that cannot be obtained by multiplying out the factors on the left hand side, i.e., a summand whose denominator must be divisible through a prime greater than if one decomposes into prime factors all numbers between and Two things should be pointed out about the above transformation. First, although Behmann wants to use this theorem as an example of how the general strategy for turning indirect existential proofs into direct proofs is supposed to work, it should be remarked that the constructivization of Euler’s proof does not follow from syntactic manipulations but rather by refining one of the initial assumptions. However, in general we have no guarantee that for every assumption of the form we would be able to provide such refinement. On the contrary, we know that in general this is not possible. Secondly, unlike Wittgenstein’s approach to the problem, Behmann seems to be already knowledgeable about which bounds are going to work for the situation at hand. Indeed, later on he points out that he could have transformed the proof by using the better inequality

which gives a bound for the next prime under

where is the natural logarithm.

4. BACK TO WITTGENSTEIN The section on “Euler’s proof” in Philosophical Grammar begins with a straightforward reflection on Euler’s proof: From the inequality

can we derive a number which is still missing from the combinations on the right-hand side? Euler’s proof that there are infinitely many prime numbers is meant to be an existence proof, but how is such a proof possible without a construction?

The argument goes like this: The product on the right is a series of fractions in whose denominators all multiples of the form occur; if there were no numbers besides these, then this series would necessarily be the same as the series and in that case the sums also would necessarily be the same. But the left-hand side is and the right-hand side only a finite number so there are infinitely many fractions missing in the right-hand series, that is, there are on the left-hand side fractions that do not occur on the right. (1974, 383; 1994, 321-2; 2000, 427) Again, it is clear that Wittgenstein discusses Euler’s equation (A). As he points out a bit further, if one extends the sum on the left-hand side until it is greater than any

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number which would be the result of the right hand product for prime numbers up to any given one, this part of the sum “must contain a term that doesn’t occur in the right hand series, for if the right hand series contained all those terms it would yield a larger and not a smaller sum” (1974, 385; 1994, 324; 2000, 429). As was pointed out, there is a passage in Wittgenstein’s manuscripts for the year 1930 where we find the following computations, which were neither reproduced in the Big Typescript, nor in Philosophical Grammar. This passage should be read in conjunction with the calculations at the end of the section on Euler’s proof in both of these: Thus, a sufficient condition for the beginning of the series first of these segments goes from

is that If I represent of the ordered segments that are then the

1 to 4

3

to

15

the third from

16 to

63

the

to

the second from

The sum of the series we have

developed up to

thus surely exceeds

Thus,

It is thus the case that in the first whole numbers, there must be one which is not divisible by any of the first numbers. (1994, 325)

We will reproduce Wittgenstein’s calculations in the appendix and limit ourselves here to a synthesis of the results. First of all, Wittgenstein solves the following general problem: if one starts from for arbitrary how far does one have to go for the harmonic series to sum up to a number i.e., to determine such that He works out a bound through algebraic manipulations (see appendix) whereby the condition is And since he thus concludes that from any point of the harmonic series one only needs to go to in order for that segment of the harmonic series to sum up to a number greater than 1. Applying the result to the harmonic series from its start (i.e., ) Wittgenstein determines that This is not as good a bound as the one used by Behmann although it is closely related since Wittgenstein’s evaluation, requires always two times as many steps as Behmann’s. This is due to the fact that Wittgenstein’s condition on gives him a very slow start when trying to majorize any number We have to assume that the full passage from MS 108 gives us a good idea of the proof by Wittgenstein that was referred to by Behmann, Kaufmann and Waismann in their exchange of letters. Therefore, Waismann’s claim (quoted above in Kaufmann’s letter dated 12.X.1930) that the two proofs are related seems to be justified.

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5. WITTGENSTEIN ON MATHEMATICAL EXISTENCE Wittgenstein’s critical discussion of Euler’s original proof and his constructive version of it are, if not of much mathematical interest, of great significance to the interpretation of his philosophy: this is the sole instance of an extended discussion of a specific existential proof and the sole instance of a ‘proof’ in the whole of his writings and, as such, they cannot be bypassed. Wittgenstein’s comments on Euler’s proof are extremely critical: Here again we have that remarkable phenomenon that we might call proof by circumstantial evidence in mathematics – something that is absolutely never permitted. It might also be called a proof by symptoms. The result of the summation is (or is regarded as) a symptom that there are terms on the left that are missing on the right. The connection between the symptom and what we would like to have proved is a loose connection. That is, no bridge has been built, but we rest content on seeing the other bank. All the terms on the right-hand side occur on the left, but the sum on the left-hand side is and the sum of the right-hand side is only a finite number, so there must ... but in mathematics nothing must be except what is. The bridge has to be built. (1974, 384; 1994, 322; 2000, 427)

These critical comments amount to a straightforward rejection of the validity of existential proofs: he calls them “proofs by circumstantial evidence” and says that they are “absolutely never permitted”; alternatively, he calls them “proofs by symptoms” but claims that “there are no symptoms” in mathematics. He uses the metaphor of the bridge and likens existential proofs to resting content with seeing the other bank, while he requests that “the bridge has to be built”. A further critical remark in the same section can help us to understand Wittgenstein’s more general thoughts about existential proofs: We might also put the question thus: if you had only this proof, what would you bet on it? If we discovered the primes up to N, could we later go on for ever looking for a further prime number – since the proof guarantees that we will find one? – Surely that is nonsense. For “if we only search long enough” has no meaning. (That goes for existence proofs in general). (1974, 384; 1994, 323; 2000, 428)

Not only is this reasoning perfectly in line with Wittgenstein’s proof, which provides an interval within which one will find a new prime number, but it also squares perfectly well with the very reasoning of Brouwer and Weyl which is at the basis of their rejection of the Law of Excluded Middle.22 Moreover, it bears an obvious relation to Kronecker’s demand that an existential proof must be accompanied by a bound for the existential if it has to satisfy the demands of mathematical rigor. Wittgenstein’s critical discussion of Euler’s original proof and his constructive version of it are also extremely useful because they allow us to infuse meaning into his more general pronouncements about mathematics. (From an exegetical point of view, to ignore or to bypass these remarks and the proof would simply amount to plain dishonesty.) For example, one finds in the very passage of MS 108 that we

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have been referring to, the following remark, which encapsulates Wittgenstein’s central thought about foundations of mathematics: In mathematics everything is algorithm and nothing is meaning; even when it doesn’t look like that because we seem to be using words to talk about mathematical things. Even these words are used to construct an algorithm. (1974, 468; 1994, 321; 2000, 494)

A similar remark was uttered by Wittgenstein, during a meeting with Schlick and Waismann in June 1930: I believe that mathematics, once the conflict about its foundations has come to an end, will look just as it does in elementary school where the abacus is used. The way of doing mathematics in elementary school is absolutely strict and exact. It need not be improved upon in any way. Mathematics is always a machine, a calculus. The calculus does not describe anything […] A calculus is an abacus, a calculator, a calculating machine; it works by means of strokes, numerals, etc. (1979, 106)

And remarks to the same effect made their way into the typescript of 1931 which was edited under the title Philosophical Remarks: Let’s remember that in mathematics, the signs themselves do mathematics, they don’t describe it. The mathematical signs are like the beads of an abacus. (1975, § 157) … we can’t describe mathematics, we can only do it. (And that of itself abolishes every ‘set theory’.) (1975, 159)

“In mathematics everything is algorithm”: it is obvious that the rejection of (nonconstructive) existential proofs is entailed by this very Kroneckerian thesis. Perhaps it is worth pointing out here another element contained in these remarks, i.e. the idea that there are no descriptions in mathematics. According to Wittgenstein it is a mistake to think that a foundational theory (set theory or Principia Mathematica) could be a description, hence a ‘theory’. As he would put it “ Calculation with letters is not a theory” (1979, 136); “what is calculus must be separated off from what attempts to be (and of course cannot be) theory” (1974, 468; 2000, 494). This is the true ground of Wittgenstein’s limited anti-theoretical and anti-foundational stance, a stance that has been entirely misunderstood by those who claim that he held no ‘theses’ at all.23 6. VIENNESE FINITISM

What about Wittgenstein’s reaction to Kaufmann’s conjecture? If there is any discussion of it in Wittgenstein’s Nachlaß, it remains to be found. A few remarks are nevertheless in order. To begin with, although it seems from the available evidence that Wittgenstein never met with Behmann, it is also clear that he was not kept out of the loop. A copy of the last version of Behmann’s paper was sent to Wittgenstein, who must have known about Kaufmann’s conjecture. There are at any rate traces left of contacts between Wittgenstein and Kaufmann. For example, in a letter to Kaufmann dated April 6, 1930, Wittgenstein wrote:

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Thank you very much for sending me your book. Sadly, I am too busy to be able to read it. I hear from Mr. Waismann that our views coincide on many points.24

There is also the incredible story of a suitcase bearing the name “Kaufmann” that was apparently found in Wittgenstein’s lodgings in Cambridge after his death and which Rush Rhees mistakenly sent to Walter Kaufmann, only later realising that the owner must have been Felix Kaufmann. Later, Rhees unsuccessfully tried to recover the suitcase; one will never know its contents.25 It is most probable that Wittgenstein would have found Kaufmann’s attempt at grounding arithmetic with help of Husserl’s phenomenology uncongenial. However, Kaufmann’s finitism is not very far from Wittgenstein’s own Standpunkt, which also should be seen as a form of finitism.26 It should be recalled here that, just prior to Behmann’s visit to Vienna, Waismann had just participated in the famous meeting at Königsberg organized by the Wiener Kreis and Hans Reichenbach’s Gesellschaft für empirische Philosophie, by giving a paper at a symposium on foundations of mathematics which included presentations by Rudolf Carnap on logicism, Arend Heyting on intuitionism, and Johann von Neumann on formalism.27 Waismann’s paper, entitled ‘Über das Wesen der Mathematik. Der Standpunkt Wittgensteins’ (1982), was not ready to be included alongside the others in the 1931 issue of Erkenntnis devoted to the Königsberg meeting; it appeared only in 1982. It is clear from Wittgenstein’s attitude prior to the meeting that he took the opportunity to have his views publicized very seriously. There was, therefore, such a thing as Wittgenstein’s Standpunkt. Waismann’s presentation of his ideas, although rather faithful, was not formal. As Carnap pointed out in the discussion that was to be published in the same issue of Erkenntnis, the Standpunkt Wittgensteins had not yet reached a stage of development at which it could be evaluated (Hahn et alii 1931, 141). It never reached that stage, either in Waismann’s or in Wittgenstein’s own work. We are now left with the task of reconstructing this Standpunkt Wittgensteins and the above discussion of his remarks on the constructivization of Euler’s proof should be seen as a contribution to this task. That Kaufmann’s finitism is not very far from Wittgenstein’s own Standpunkt is supported by the above-quoted letter, where Wittgenstein writes: “I hear from Mr. Waismann that our views coincide on many points”. Therefore, something like Kaufmann’s conjecture could not have been very far from Wittgenstein’s mind. This would go a long way to explain his interest in constructivizing Euler’s proof. But, before one might be tempted to speak of an indigenous, Viennese form of finitism, it should be pointed out that Kaufmann’s conjecture implied that classical mathematics was already constructive and that Brouwer’s critique was to leave it essentially untouched. Wittgenstein did not believe this. In his manuscripts for the years 1930-31, we find claims to the contrary, e.g.: What will distinguish mathematicians of the future from those of today will really be a greater sensitivity, and that will – as it were – prune mathematics; ... (1974, 381; 1996, 23; 2000, 426)

It is clear that Wittgenstein had no illusions about the effects of philosophical

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clarity on mathematics or about the consequences of his Standpunkt, parts of which was the rejection of pure existential proofs.

7. APPENDIX Wittgenstein’s goal is to determine what bound is necessary for such that He begins by transforming the left-hand side into

This, in turn, can be written as

At this point, in order to work out a bound, Wittgenstein’s divides the above sum into a first part up to and a second part. Moreover, since

we have

We now consider the expression in square brackets. The 1’s sum up to difference

is such that we can bound every one of its terms by a multiple of Indeed.

And in general,

and the

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Thus,

As for the second part of the sum

Wittgenstein looks at the sum obtained from it by replacing each summand by Since there are many summands, this new sum amounts to Also, it is clearly less than the sum from which it is obtained. Now the question becomes: Knowing a bound on

how big must we choose

so that

The left hand side is equal to

Thus,

iff iff iff iff iff

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iff iff

The final observation consists in noticing that majorizes for all Remark: in Wittgenstein (1994), p. 325, the symbol should be read as In Wittgenstein (1974), p. 386 and (2000), p. 429 some of the equality signs should be

NOTES 1. For details about Behmann’s work in the foundations of mathematics, see Mancosu (1999). 2. See Mancosu (2002), §1, for a discussion of the meaning of that passage. The paper also recon3.

4.

5. 6. 7. 8.

9.

10.

structs the debate surrounding the discussion of Behmann’s ‘proof’. “1. Ausschluß nicht-konstruktiver Existenzbeweise (insbesondere des Auswahlaxioms). 2. Ausschluß nicht-prädikativer Existenzbeweise (soweit nicht bereits durch (1) betroffen). 3. Ausschluß von Begriffen höherer Stufe (Beschränkung auf den sogennanten “engeren Funktionenkalkül).” Behmann(1930), p.l. “Hierzu hat neuerdings Herr Kaufmann eine interessante Vermutung ausgesprochen [...] Er ist der Ansicht, daß auch ein indirekter Existenzbeweis, sofern er der Anforderung (1) genügt, seiner Natur nach konstruktiv sei, genauer gesagt, auf einer verstecken Aufweisung beruhe, die sich durch eine geeignete Analyse des Beweises zwangläufig zur Evidenz bringen lassen müsse.” Behmann (1930), p.l. On Gödel’s objection to Behmann’s paper, see Mancosu (2002), §5. This aspect of Behmann’s paper has been studied by Mancosu (2002). For a list of various proofs of the infinity of prime numbers, see Dickson (1952), pp. 413-15. Euclid’s proof, a typical case of reductio ad absurdum, is as follows: suppose that there is a greatest prime number, One defines from the primes the number which must be either prime or composite. If it is prime, then we have a contradiction, since it would be bigger than all the prime numbers smaller or equal to If it is composite, it must be divisible exactly by a prime number. But this prime divisor cannot be any prime smaller or equal to because they would all leave a remainder of 1. Therefore there must be another prime number, bigger than Notice that this is a special form of Riemann’s zeta function The zeta function for real z appears in a work by Euler dated 1744, where he introduced where the ’s are prime numbers. The previous equation involves the summation formula for the geometric series, i.e. for any prime we have Note that on account of the unique factorization theorem

(which is independent of the infinitude of the prime numbers) every natural number appears only once as denominator in the expanded product. Moreover, the series obtained by multiplying absolutely convergent series is also absolutely convergent and its sum is the product of the sums in the series’ factors. 11. “Auch diesem Beweise kann man ebenso wie dem Euklidischen eine solche Form geben, dass sich aus ihm ein Intervall ergiebt, innerhalb des