Semantics and Conceptual Change Jerrold J. Katz The Philosophical Review, Vol. 88, No. 3. (Jul., 1979), pp. 327-365. Stable URL: http://links.jstor.org/sici?sici=0031-8108%28197907%2988%3A3%3C327%3ASACC%3E2.0.CO%3B2-9 The Philosophical Review is currently published by Cornell University.
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SEMANTICS AND CONCEPTUAL CHANGE* Jerrold J. Katz
T
he discussion of conceptual change that has taken place over the last two decades is peculiar in a n important respect: meaning and change of meaning loom large in these discussions, yet no consideration seems to have been given to what linguistics says on these topics. It is almost perverse that in discussions of science carried out by philosophers of science, in which highly controversial claims concerning science turn on assumptions about meaning, there is no attempt to use ideas from the science that studies meaning.' In ignoring linguistics, these discussions restrict themselves to an overly narrow range of positions on conceptual change in science. In the present paper, I will show that linguistics has a significant contribution to make in extending this range of positions. I will show that there are ideas in linguistics that lead to a new position on con-
*This paper has been presented at the Conference on Conceptual Change at Ripon College, and to the philosophy departments at the University of Toronto, Columbia University, University of Massachusetts in Amherst, and the State University of New York at Albany. I wish to thank Joe Bevando, Tamara Horowitz, Paul Horwich, Arnold Koslow, Keith Lehrer, Sid Morgenbesser, Tom Nagel, Charles Parsons, and Peter Unger for their comments on earlier drafts. I wish to specially thank Virginia Valian for her helpful comments on the final draft. .-- ..~ -~. -.I Ironically, the closest thing to such an attempt in the literature is a neglected, early piece by Putnam (Putnam, H., "How Not to Talk about Meaning," in Boston Studies zn The Philosophy of Science, Vol. 11, R. S. Cohen & M. W. Wartofsky, eds., Humanities Press, New York, 1965, pp. 205-222) in which he defends the ordinary distinction between meaning and belief against Feyerabend's conception of theory-relative meaning. What is ironic, as we shall see below. is that it is now necessarv to defend the same distinction against Putnam. It is also worth mentioning for the record that ~eyerabend'sreaction was to make the pronouncemen; that "As far as I am concerned, even the most detailed conversations about meanings belong in the gossip columns and have no place in the theory of knowledge." (p. 230) ' Shapere, D. "Meaning and Scientific Change," in Mind and Cosmos: Essays in Contemporary Science and Philosophy, Vol. 111, University of Pittsburgh Series in the Philosophy of Science, University of Pittsburgh Press, 1966, pp. 41-85. -
-
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ceptual change in science. I will exhibit its advantages over the positions taken thus far, and I will show how it might clarify disputes in the philosophy and history of science. The discussion of conceptual change has been carried out largely as a debate between the "new philosophers of science," as Shapere refers to Kuhn, Feyerabend, and Toulmin, and the older, logical empiricist philosophers of science.' Philosophy of science, on the logical empiricist conception, is "metascience," on analogy to metalogic. It concerns, as Shapere characterizes it, the "logical form" . . . of scientific statements rather than their "content," with, for example, the logical structure of all possible statements claiming to be scientific laws, . . . with the logical skeleton of any possible scientific theory, rather than with particular actual scientific theories.'
This aim is to be achieved using the techniques of modern mathematical logic in approaching . . . problems . . difficulties were to be overcome . . . by giving a more satisfactory reformulation in terms of that logic."
The particular choice of applied predicate calculi for such reformulation is guided by an empiricist metaphysics which claimed that all scientific theory must, in some precise and formally specifiable sense, be grounded in experience, both as to the meanings of terms and the acceptability of assertions.
Scientific theories were conceived of as axiomatic systems connected to experience through rules that interpret their theoretical vocabulary exclusively in terms of an observation vocabulary. Scientific development is a process of stockpiling truths and weeding out falsehoods.
' Ibid., p. 42. Ibid., p. 42. Ibid., p. 44. Ibid., pp. 44-47. See, for example, Hempel, C. G., "Problems and Changes in the Empiricist Criterion of Meaning," Revue Internationale de Philosophie, Vol. IV, No. 11, 1950, pp. 41-63, and Hempel, C. G., "Implications of Carnap's Work for the Philosophy of Science," in The Philosophy of RudolfCarnap, A. Schilpp, ed., Open Court Press, 1963, pp. 685-710.
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A number of things prepared the way for the rebellion against this "old philosophy of science.'' The four most significant seem to be these.6 First, the old philosophy of science lost credibility because it failed to make good its promise to eliminate metaphysics through the logical analysis of language, especially to explain how the meaning of theoretical terms can be given in .~ the emphasis on terms of an observation v ~ c a b u l a r y Second, "the logical skeleton of any possible theory" made the work of these philosophers increasingly less relevant to "actual scientific theory." Third, Wittgenstein's criticism of the ideal of rational reconstruction undermined the belief that it actually removed problems. Lastly, history of science emerged as a "new professionalized discipline," with results challenging the logical empiricist's "upward and onward" picture of scientific development.' The new philosophers of science earned this title by first formulating an alternative conception of scientific theory and scientific development. Its principal feature was a picture of scientific development in which periodically sciences experience revolutions that so radically redefine them that the normal scientific tradition that emerges . . . is not only incompatible but often actually incommensurable with that which has gone b e f ~ r e . ~
The emerging theory does not refute the old theory, it replaces it. Since the replacement can so fundamentally transform the science that no common methodological basis exists on which to compare the claims in the old and new theories, scientific development is not cumulative. The significance of meaning and change of meaning for scientific development can be appreciated from the fact that both the cumulative and the noncumulative pictures of scientific development are grounded in accounts of meaning. Logical empiricists ground their picture in an empiricist account of "Meaning and Scientific Change," pp. 46-48. T. S., The Structure of Scientfic Revolutions, University of Chicago Press, Chicago, 1962, p. 102. There is a difficulty with Kuhn's formulation here. Since he intends "incommensurability" to apply when the theoretical terms in the old and the emerging traditions are- interpreted so that the basic principles of these traditions are logically independent, the two traditions cannot be "incompatible" when they are "incommensurable". I will assume that Kuhn's reference to incompatibility is just a slip.
' Kuhn,
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meaning. The account makes it reasonable to think that there is a theory-neutral vocabulary of observation terms that provides theory-independent, experiential meanings for the theoretical terms of all scientific theories. Thus, there is a basis for claiming that the same meaning can be assigned to a term in different theories and that translatability between theories is always possible. The new philosophers of science, too, ground their picture in an account of meaning. The failure of the logical empiricists to vindicate the empiricist account of meaning enabled the new philosophers of science to replace the empiricist account with their account of meaning on which there is no theory-neutral basis for interpreting scientific terms. Such terms are idiosyncratically interpreted in the theories employing them and their semantics is relative to that theory. Feyerabend claims: the meaning of every term we use depends upon the theoretical context in which it occurs. Words do not 'mean' something in isolation; they obtain their meaning by being part of a theoretical system."
Hence, if the new theory emerging from a revolution is sufficiently different from the old in respect of the interpretation of terms, the theories, not surprisingly, turn out incommensurable. The controversial claims of the new philosophers of science about scientific theory and scientific development thus depend on replacing the logical empiricist's absolutist account of meaning with an account on which meaning is theory-relative. Given that there is no a priori reason to suppose that these two accounts of meaning are the only possible accounts, the question arises of why philosophers haven't tried to formulate an absolute semantics that does not rest on the logical empiricists' empiricism and its dubious theoretical term/observation term distinction." An answer is not hard to find. The new philosolo Feyerabend, P. "Problems of Empiricism," in Beyond the Edge of Certainty, R. Colodny, ed., Prentice-Hall, Inc., Englewood Cliffs, 1965, p. 180.
" Even as resourceful a critic of the new philosophy of science as Shapere tries instead to deemphasize the impoftance of meaning. (See "Meaning and Scientific Change," pp. 68-69). Shapere claims that there is a "danger" in making use of the notion of meaning. He says: "-we expose ourselves to the danger of relegating some features of the use of a term to the 'less important' status of not being 'part of the meaning.' Yet those very features, for some purposes, may prove to be the very ones that are of central importance in
SEMANTICS AND CONCEPTUAL CHANGE
phers of science's position on meaning has broad support in the history and philosophy of science. The position that meaning is theory relative has the authority of one of the most widely respected figures in the history and philosophy of science, Pierre Duhem. Duhem wrote: According to whether we adopt one theory or another, the very words which figure in a physical law change their meaning, so that the law may be accepted by one physicist who admits a certain theory and rejected by another physicist who admits some other theory."
The position is encouraged by other influential figures like N. R. Campbell. Also, putting the issue of the theoretical/observational vocabulary distinction to one side, there is not all that much different about the old and new philosophies of science. In Carnap's case, this is clear just from the unrestricted ontological freedom we are given in answering so-called "external questions." The similarity between the old and new philosophy comparing two uses, for relative importance of features of usage must not be enshrined in a n absolute and a priori distinction between essential and inessential features. It thus seems wiser to allow all features of the use of a term to be equally potentially relevant in comparing the usage of the terms in different contexts. But this step relieves the notion of meaning of any importance whatever as a tool for analyzing the relations between different scientific 'theories.' " First, the distinction between "part of the meaning" and "not part of the meaning" is not the distinction between "essential" and "inessential." But even if it were, it is surely just an equivocation on these terms to take them, as Shapere does, to carry the force of, respectively, '"important" and "unimportant." There is no reason to suppose that, because some feature is not part of the meaning of a term or not essential, it is less important than some feature that is part of the meaning of the term. There seems to be widespread confusion among first-rate philosophers of science over the difference between definitional and essential properties. For instance, N. R. Campbell's criticism of the distinction between defining and nondefining properties of scientific terms rests on such a confusion. Campbell poses the question as follows: "Are there properties of silver which simply define what we mean by silver and such that, if they were altered, the substance would not be silver; and are there on the other hand nondefining properties, such that they might be changed without affecting the fact that the substance in question is silver?" Campbell, N. R., Foundations of Science, Dover Publications, Inc., New York, 1957, p. 47. But properties such that if something did not have them, it would not be the same thing (p. 47) are essential properties but not necessarily definitional properties. Being the single even prime is a property such that nothing without it can be the number two, but it is not a definitional property of two. I' Duhem, P. The Aim and Structure of Physical Theory, Princeton University Press, Princeton, 1954, p. 167.
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also follows from other, more widely held, doctrines of Carnap's.13 Moreover, the position of the new philosophers of science is significantly strengthened by the hostility of present philosophical opinion toward the traditional notion of meaning. The effect of this hostility is to prevent us from restricting principles for interpreting terms from entire systems of beliefs to analytic beliefs. As Quine put it: Once I reject the distinction between analytic sentences and other communitywide beliefs, however, my nearest approximation to a null theory is the class of all community-wide beliefs. l 4
Although Quine's attack on the analytic-synthetic distinction initiated this hostility, it has been kept up, on the one hand, by followers of Quine's like Davidson and Harman,15 and on the other, by philosophers coming to the issue of the separability of language and theory from the study of reference like Putnam and Kripke. l6 With widespread opposition to distinguishing the linguistic component of a theory from the rest of the theory as that part which interprets the terms of the theory, it is easy to see why the account of meaning of the new philosophers of science ran into so little trouble. Since their relativization of meaning to theory was the real force behind the radical doctrines about the no;cumulativeness of scientific development, their conformity to orthodox opinion on the language/theory distinction shielded l3 See Carnap, R., "Empiricism, Semantics, and Ontology," in Semantics and the Philosophy of Language, L. Linsky, ed., University of Illinois Press, Urbana, 1952, pp. 208-230. See English, J., "Partial Interpretation and Meaning Change," The Journal of Philosophy, Vol. LXXV, No. 2, 1978, pp. 57-76 for an argument that widely accepted logical empiricist doctrines are close to the doctrines of the new philosophers of science. lJQuine, W. V. "Reply to Chomsky," Synthese, Vol. 19, No. 1/2, 1968, p. 282. j5 Davidson, D. "Truth and Meaning," Synthese, Vol. 17, No. 3, 1967, pp. 304-323; Harman, G. Thought, Princeton University Press, Princeton, 1973, pp. 84-111. l6 Putnam, H. "It Ain't Necessarily So," T h e Journal of Philosophy, Vol. LIX, No. 22, 1962, pp. 658-671; "Is Semantics Possible?", Metaphilosophy, Vol. 1, 1970, pp. 189-201; "The Meaning of 'Meaning,"' Language, Mind, and Knowledge, Vol. VII, Minnesota Studies in the Philosophy of Science, K. Gunderson, ed., University of Minnesota Press, 1975, pp. 131-193. Kripke, S. "Naming and Necessity," Semantics of Natural Language, D. Davidson & G. Harman, eds., D. Reidel Publishing Co., Dordrecht, Holland, 1972, pp. 253355.
S E M A N T I C S A IVD CONCEPTUAL C H A N G E
these doctrines from the most basic form of criticism to which they are open. l7
With so widespread a skeptical attitude toward the language/ theory distinction, there are surprisingly few serious arguments to show that the distinction cannot be drawn. To my knowledge, there are only three. In this and the next two sections, I shall show that all three are inadequate. Then I will develop an account of meaning and of the language/theory distinction that is absolutist like the logical empiricist account but makes none of the dubious assumptions that got the latter account into trouble. Finally, I sketch the implications of my account for conceptual change in science. Perhaps the best known attempt to argue that the language/ theory distinction cannot be drawn is Quine's argument that meaning and related notions cannot be explained well enough for them to qualify for use in scientific theories about language. Feyerabend's less well known argument that in a conflict between two different high level background theories there is in principle no possibility of translation comes to much the same thing as Quine's indeterminacy of translation.'' Furthermore, Feyerabend's account of how different high level background theories are comparable in terms of his "pragmatic theory of observation" is quite similar to Quine's account, in his theory of stimulus meaning, of how different languages confront the same experience. lg Thus, I will take Quine's argument as representative of Feyerabend's and others' attempts to establish that there is no truth of the matter about questions of meaning and synonymy. As will be recalled, the argument in "Two Dogmas of Empiricism" begins by considering three definitional ways of explain" For my response to the Putnam and Kripke papers, see Katz, J. J. "A Proper Theory of Names," Philosophical Studies, Vol. 31, No. 1, 1977, pp. 1-80. The present paper is the discussion promised in footnote 60 (p. 78). '"ee Shapere's discussion of Feyerabend'i claim in "Meaning and Scientific Change," pp. 57-58; Quine: W. V. Word and Object, M . I . T . Press, Cambridge, 1960, pp. 26-79. l9 "Problems of Empiricism," pp. 217f; Word and Object, pp. 80f.
ing semantic notions: lexicographical definition, rational reconstruction, and notational abbreviation." Quine rejects all three as incapable, in principle, of clarifying such notions. Quine then takes up two theoretical ways of explaining these notions: interchangeability and semantical rules. He tries to show that these methods of clarification also can be dismissed because they lead to circularity. Quine concludes that there is no analytic-synthetic distinction to be drawn. The argument to this conclusion has a logic that has eluded both Quine's critics and his sympathizers. Grice and Strawson commit the original sin in suggesting that Quine's argument proceeds invalidly from cases where the analytic-synthetic distinction has not been adequately explained to the conclusion that there is nothing to explain." Putnam follows them and suggests that there must be something deeper to Quine's argument, otherwise "it is puzzling why this [argument] is supposed to be a good a r g ~ m e n t . "The ~ ~ logic of Quine's argument is this. Quine's essay has three polemical sections: "Definition," "Interchangeability," and "Semantical Rules." In the first, Quine considers explicit definition in all its forms, and in the second and third, he considers implicit definition in the two relevant areas of science, linguistics and logic. The point that Grice, Strawson and Putnam m'iss is that Quine's argument exhausts the relevant areas where a method for clarification of semantic notions might exist. Thus, if he can show that there is no method that can do this in one of these areas, it is reasonable to think the notion of meaning is not clear enough to ground a theory of a priori truth. Quine's dismissal of explicit definition is unobjectionable: notational abbreviation rests on arbitrary stipulation and both rational reconstruction and lexicographical definition assume prior synonymy relations instead of explaining them. Furthermore, Quine's dismissal of implicit definition in logic, namely postulate or rule specification, modeled on definitions of logical ''Quine, W. V. From a Logical Point oJ View, Harper & Row, Inc., New York, 1953, pp. 20-46. Grice, H. P. and Strawson, P. F. "In Defense of a Dogma," The Philosophical Review, Vol. LXV, No. 2, 1956, pp. 141-158. 22 Putnam, H. " 'Two Dogmas' Revisited," in Contemporary Aspects of Philosophy, G. Ryle, ed., Oriel Press, London, 1976, p. 203.
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truth in first orde; logic, is also unobjectionable: specification of meaning postulates or semantical rules enables us to "understand what expressions the rules attribute analyticity to, but we do not understand what the rules attribute to those expresthe point that has been missed, Quine's argus i o n ~ . "Given ~ ment would go through if his treatment of implicit definition in linguistics were sound. Putnam compounds the original sin by misrepresenting Quine's argument that synonymy is hopelessly unclear. Putnam says, "The only evidence that Quine produced to support this remarkable claim was that he, Quine, could not clarify the notion in a few pages."24 In those "few pages," however, Quine mounts a very sophisticated argument against synonymy. Putnam's reconstruction of Quine's argument as a n induction from a sample of one does the argument a n injustice. Quine's argument is rather this: Quine poses the problem of clarifying a notion of synonymy in linguistics as that of showing that it is possible to separate synonymous pairs of expressions from nonsynonymous pairs on the basis of an interchangeability or substitution test. H e then observes that either the corpus containing the "substitution frames" is intensional, because it contains expressions like "Necessarily, bachelors are bachelors," or extensional. If the corpus contains such intensional contexts, the question has already been begged. If the corpus does not contain them, every attempt to state a n interchangeability test must beg the question. Such a test must cite the property to be preserved when and only when synonyms replace synonyms. But since the choice is between truth and analyticity, no acceptable test can be formulated. Requiring the substitution to preserve truth fails to separate synonymous pairs of expressions from nonsynonymous but coextensive pairs while requiring analyticity assumes meaning is unproblematic and begs the question. This argument. would show that the central notions of the theory of meaning cannot be made clear enough for linguistics I f Quine can legitimately assume that interchangeability tests are the proper criteria for determining what is clear enough for this science. Though Quine's assumption is mistaken, he had
" From a Logical Point 24 "
of View, p. 33. 'Two Dogmas' Revisited," p. 204.
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good grounds for making it a t the time. T h e assumption came from the then dominant theory of language in linguistics, the taxonomic theory of grammar. This theory not only had the authority of scientific orthodoxy, but, being behaviorist, empiricist, and physicalist, it also had the proper philosophical creden'~ himself is quite explicit about appealing tials for Q ~ i n e . Quine to the taxonomic theory of grammar for a conception of the way that linguistics explains linguistic notions: So-called substitution criteria, or conditions of interchangeability, have in one form or another played central roles in modern grammar [viz., taxonomic theory]. For the synonymy problem of semantics such a n approach seems more obvious still. '"
Quine also is quite explicit about the fact that it is this model of explanation that he used in his examination of the notion of synonymy. 27 T h e true reason why Quine's argument fails is that it had the ground cut from under it by the dissolution of the taxonomic theory of grammar. Logically speaking, the "vicious circle" shows no more than that either notions like synonymy cannot be made sufficiently clear or the standard of clarity used in judging them is not adequate. It is plausible to think that these notions are inherently unclear in linguistics if it is, in fact, plausible to think that the standard is adequate. But there is no valid inference to the conclusion that the central notions in the theory of meaning are hopelessly unclear f t h e assumed standard of clarity is discredited. Since Chomsky's refutation of the taxonomic theory as an acceptable scientific theory of language establishes the inadequacy of substitution tests in linguistics, Quine's argument is a casualty of Chomsky's revolution in linguistic^.^^ Not only does Chomsky's revolution bring about the collapse of Quine's argument against meaning, it introduces a new conception of the proper way to clarify linguistic notions. Taxo'Wompare remarks of Bloomfield, the founder of the taxonomic theory in linguistics, such as those in Bloomfield, L. "Language or Idea?" Language, Vol. 12, 1936, p. 93 with those of Quine's,such as From a Logical Point of View, p. 48. 'Tram a Logical Point of View, p. 56. 27 Ibid., pp. 56-57. See Katz, J. J. "Logic and Language: An Examination of Recent Criticisms of Intensionalism," in Language, Mind, and Knowledge, pp. 36-63.
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nomic theory conceives of grammars as data-cataloguing devices, compact tabulations of the distributional regularities in a sample of speech. It thus conceives of clarification in terms of the operationalism of substitution tests. Chomsky conceives of grammars as idealizations of the knowledge of a language that speakers exercise in verbal behavior. This makes linguistic theorizing like theorizing in the advanced sciences. It thus legitimizes in linguistics the same standard of clarity employed in the advanced sciences. Notions of any sort can appear in the rules of a grammar so long as, first, they can be precisely stated, and second, their appearance can be justified as a theoretical posit, that is, as essential to the predictions and explanations of the simplest theory of the phenomena. In linguistics, this means accounting for grammatical properties and relations. Furthermore, Chomsky's theory contained a new way of defining syntactic properties and relations that could serve as a model for definitions of semantic properties and relations. The crux of the idea was to set up the syntactic component of a grammar as an explication of the syntactic competence of the ideal speaker-hearer, to explicate this competence in terms of syntactic rules that generate syntactic representations of sentences, and then to define syntactic properties and relations on the output of these rules. For example, a string of words is marked as well-formed just in case it has a syntactic representation; two strings are marked as constituents ofthe same syntactic type just in case they are categorized in the same way in syntactic representation. O n this model, semantic theory was set up as a theory of the semantic competence of the speaker. Semantic theory specifies semantic rules and definitions of semantic properties and relations stated in terms of their output. The semantic rules consist of a set of dictiona7y rules and a projection rule. The dictionary rules assign formal semantic representations to lexical items as descriptions of their senses. The projection rule combines semantic representations of lexical items to form semantic representations of the compositional meaning of syntactically complex constituents. Semantic properties and relations are defined, in analogy to syntactic properties like well-formed, on the output of these semantic rules. For example, a sentence
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or expression in a sentence is marked as meaningfiul just in case it is assigned at least one semantic representation, meaningless just if it is assigned none, and ambiguous just in case it is assigned two or more. Two expressions or sentences are marked as synonymous (on a sense) just in case they are assigned the same semantic representation. zs Given the possibility of a semantic theory, Quine's thesis of indeterminacy of translation has nothing to support it. Hypotheses about the semantic component of a grammar of a language can be justified by checking their predictions about the meaningfulness, meaninglessness, ambiguity, and other semantic properties and relations of sentences against the judgments of speakers of the language. Evidence about the semantic properties and relations of expressions in languages can be used to confirm the existence of synonymy or translation relations, even in the case of radical translation. Bilingual speakers can, in principle, provide evidence, both direct and indirect, about whether or not, for example, "gavagai" has the same sense as "rabbit" or "rabbit stage" or "undetached rabbit part." We can ask such speakers for their judgment about whether "gavagai" is synonymous with any of these three English expressions. We may get a clear, unequivocal response. We may not. If we do, we have evidence. If not, we can ask a somewhat more sophisticated question or a somewhat more sophisticated informant. For example, we might come back with the question whether << gavagai" bears the relation to some expression (in either language) that "undetached finger" bears to "hand." There are indefinitely many such further questions, and indefinitely many potential informants. 30 Since there are no a priori reasons to think that, with sufficient effort, the evidence cannot be made clear enough to compensate for inductive underdetermination, there ' T o r a comprehensive presentation of the theory referred to, see Katz, J. J . Semantic Theory, Harper & Row, Inc. New York, 1972. "Semantic intuitions of speakers may not always be clear and in some cases may not remain clear, but, as Chomsky points out in Syntactic Structures, Mouton & Co., 'S -Gravenhage, 1957, pp. 13-17, grammar construction is ex~licationand in ex~licationunclear cases can be decided on the basis of what the relevant rules of the grammar imply about these cases when these rules are set up in the simplest way to handle the clear cases.
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is as much a fact of the matter about identity of sense as about anything else in science.
Putnam claims that Quine's real argument is the "historical argument" that "no statement is immune from revision" because "Revision even of the law of excluded middle has been proposed as a means of simplifying quantum mechanics; and what difference is there in principle between such a shift and a shift whereby Kepler superceded Ptolemy, or Einstein Newton, ~~ quibbling about whether this or Darwin A r i ~ t o t l e ? "Without is the real argument for Quine, let us see whether the argument amounts to anything. O n Putnam's account, Quine is saying three things: (a) "Open-mindedness even to the extent of being prepared to revise logical laws is necessary in the scientific enterprise"; (b) "previous revolutions have required us to give up principles that were once regarded as a priori"; (c) "the proposal to use a nonstandard logic in quantum mechanics is not fundamentally dtfferent from the proposal to use non-Euclidean geometry in the theory of space-time."32 If this is what Quine's argument comes down to, it is easy to answer: (a') Consistency takes precedence over open-mindedness. Open-mindedness to the extent of revising logical laws clutters the mind with every thought. (b') While it is true that previous revolutions have required us to give up principles that were once regarded as a priori, none could have required us to give u p ones that were actually a priori. (c') Putnam gives no argument that the two proposals are "not fundamentally dzflerent." Thus, one can reply that a case of standard, logic is different from the case 3' From a Logical Point o f View, p. 43. Putnam makes the claim on pages 205 and following. j2 'lrTwo Dogmas' Revisited," pp. 205-206,
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of Euclidean geometry. Euclidean geometry was once a part of the physical theory of space-time, but standard logic was never a part of quantum mechanics. Standard logic was always a putative theory of logical implication, nothing more. Euclidean geometry remains the correct theory of a mathematical space even after being replaced by a non-Euclidean geometry in the physical theory of space-time. If standard logic were found to license invalid inferences in quantum mechanics, standard logic would be replaced by a nonstandard logic as our theory of logical implication (rather than as part of quantum mechanics) and standard logic then would not be the correct theory of anything. The rationalist view that logical laws are a priori truths allows that statements in a putative theory of logical implication can be discredited by examples from an actual science (just as it allows them to be discredited by examples from science fiction). It cannot allow that such statements are part of an empirical theory, no matter how broad,33but there is no argument to show this. Putnam finds Quine's holistic picture of knowledge is a forceful argument for the claim that there is no difference between logical and empirical laws. This is Quine's holistic picture of knowledge. T h e totality of our so-called knowledge or beliefs, from the most casual matters of geography and history to the profoundest laws of atomic physics or even of pure mathematics and logic, is a man-made fabric which impinges on experience only along the edges. Or, to change the figure, total science is like a field of force whose boundary conditions are experience. A conflict with experience at the periphery occasions readjustments in the interior of the field. T r u t h values have to be redistributed over some of our statements. Reevaluation of some statements entails reevaluation of others, because of their logical interconnections-the logical laws being in turn simply certain further elements of the field. Having reevaluated one statement we must reevaluate some others, which
We, of course, reject the empiricist's holistic picture of knowledge in which logic is simply the most general of the disciplines, since this picture is designed to assimilate the cases a rationalist wants to distinguish as fundamentally different.
S E M A N T I C S A N D CONCEPTUAL C H A N G E may be statements logically connected with the first or may be the statements of logical connection t h e m ~ e l v e s . ~ ~
Appeal to this picture would be disastrous because its account of knowledge is incoherent. T o see this, let us ask what the force of the term "must" is in these claims about the ramifications of a conflict with experience. Surely, the force of "must" can only be the force of logical necessity: the reevaluation of statements in the interior of the field is forced on pain of logical contradiction. If not, we could either allow conflicts with experience to stand or reevaluate some statements without reevaluating any particular others. Quine could hardly mount an argument .establishing the revisability of logical laws if we were allowed to reevaluate as we please. But if "must" has the force of logical necessity, the law of noncontradiction is immune to revision. Since logical laws are "simply certain further statements of the system, certain further elements of the field," "no statement is immune from revision," and the law of noncontradiction is a logical law, it follows that the law of noncontradiction is both immune from revision and not immune from revision.
The only other serious attempt I know of to show that there is no languageltheory distinction is the line of argument against analyticity that begins with Donnellan's criticism of C. I. Lewis35 and is made into a comprehensive critique by Putnam and others.36Lewis's account of analyticity is Kant's with Kantian talk of concepts and judgments replaced by talk of criteria of application and linguistic expressions. According to Lewis: attribution of meaning in this sense requires only two things; (1) that determination of applicability or nonapplicability of a term . . . be possible by way of sense-presentable characters, and (2) that what such characters will, if presented, evidence applicability o f . . . should be fixed in advance of the particular experience, in the determination of the meaning in question.37
,"From a Logical Poznt of Vzew, p. 42. Emphasis mine. ''"ewis, C . I. An Analysis of Knowledge and Valuatzon, T h e Open Court Publishing Co., La SZlle, 1946, pp. 3-95. ""ee references in note 16. '"Analysis of Knowledge and Valuation, p. 35.
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Sentences like "All squares are rectangles" are necessary because the criterion for applying the predicate is included in the criterion for applying the subject. But Lewis says no more about how to determine when a criterion is fixed in advance than Kant says about how to determine when a predicate concept adds nothing. . . to the concept of the subject, but merely break[s] it up into those constituent concepts that have all along been thought in it.as
Noting this failure to supply the critical explanation, Donnellan makes the point that what has been said about sentences like "All squares are rectangles" can also be said about sentences like "All creatures with hearts are creatures with kidneys.'' The required distinction between a priori and a posteriori criteria has not been supplied and we are in no position to reply that the criterion of having a kidney could fail as a test for creatures with hearts, but the criterion of being a rectangle couldn't fail as a test for squares. Donnellan sums up as follows: There is no reason, a priori, why our present usage should legislate for all hypothetical cases. Given present circumstances, the correct thing to say is that all whales are mammals. But whether this is, as we intend it, a necessary truth or contingent is indeterminate. It is indeterminate because the decision as to which it is would depend upon our being able to say now what we should say about certain hypothetical cases. 39
Even though Donnellan put his finger on the fatal flaw of the Kantian position, he allows that a sentence like "Cats are animals" expresses an analytic truth.40It was Putnam who first noticed that there is no reason to make such exception^.^^ H e saw that the nature of the flaw allowed ~ o n n e i a n ' sargument against the analyticity of "Whales are mammals" to be made against all putatively analytic sentences. Putnam's famous robot-cat case both filled the gap Donnellan had left and provided the model for the numerous similar examples that have since been brought up by Putnam, Kripke, and others. Although this line of argument works against the traditional intensionalist position of Kant, Lewis, and others, it does not 38 Kant, I. The Critique $Pure Reason, N . K. Smith, trans., Humanities Press, New York, 1957, p. 48. ""onnellan, K. "Necessity and Criteria," The Journal of Philosophy, Vol. LIX, No. 22, 1962, pp. 657-658. "'Ibid., Section 5, pp. 652-653. ." "It Ain't Necessarily So," pp. 659-660.
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show there are no analytic sentences. A semantic theory of the kind described above differs from the traditional position in just the relevant respect: such a semantic theory contains a n explanation of what it is to fix the conditions of reference for a n expression in advance of its use. I shall set out this explanation and then show how it handles the hypothetical cases cited as counterexamples. T o fix the conditions of reference in advance for expressions like "cat," we can use the principles underlying our response to Quine's indeterminacy claim, that is, the principles used in arguing that the acceptability of hypotheses about the meaning of "gavagai" depends on how well they predict judgments of speakers concerning logical properties and relations like synonymy. T o make these principles explicit, we have to do two things. First, we have to define the notions optimal semantic representation of an expression and meaning of an expression. This is done in (C ,) and (C,): (C ,) r is an optimal semantic representation of the expression e just in case, relative to the definitions of the semantic properties and relations in semantic theory, r predicts each semantic property and relation of e and of every expression e occurs in, and there is no simpler semantic representation of e that is different from r and makes the same predictions as r. 42 "There are two important points that have to be noted in connection with (C ,). First, I have simplified somewhat; the full definition has to refer to the entire grammar (as is implicit in the reference to semantic relations and to expressions in which the expression occurs). Second, the definition allows the possibility that there may be more than one optimal semantic representation, that is, more than one simplest hypothesis that predicts all the semantic properties and relations of e. I take this possibility as no more serious than the fact that the logical form of sentences in the propositional calculus may with equal simplicity be represented with formulas in disjunction and negation or formulas in conjunction and negation. Such semantic representations are strongly equivalent, in the same sense as grammatical descriptions expressed as trees with labeled nodes or as labeled bracketings. The critical point is that the possibility of more than one optimal representation cannot be used by Quinians to argue that there is a form of the indeterminacy problem within the framework I have erected. T h e reason is that
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,
(C ,) The concepts c , . . . , c , are the meaning of an expression e just in case the optimal semantic representation of e contains the semantic markers m ,, . . . , m , which represent them. The second thing we have to do is to explain in what sense meaning determines reference. The problem here is that there are two notions of reference. O n the one hand, there is the notion of the reference of sentences and other linguistic types. This notion, which we call type reference, is one on which conditions for picking out a referent are determined just by the meaning of the expression in the language. The notion appears in various philosophical contexts. One is the standard criticism of the theory that meaning is reference, namely, that this theory falsely predicts that the coreferential but nonsynonymous expressions "creature with a heart" and "creature with a kidney" are synonymous. The relation of coreference here is type coreference. O n the other hand, there is the notion of the reference of utterances or uses of linguistic types. This notion, which we call token reference, is one on which conditions for picking out a referent are determined not only by the meaning of the expression in the language but also by contextual factors like the beliefs of the speaker and audience. The notion appears in descriptions of particular referential acts such as Mark Anthony's use of "honorable men" to refer to the Roman senators who murdered Caesar. Traditional intensionalists like Frege make the unqualified statement that meaning determines reference. Their critics have reasonably taken these statements to express the false thesis that meaning determines token reference. In this way, intensionalism deserves some of the grief it has received. But, having separated type and token reference, we can disambiguate traditional statements of the relation between meaning and reference and subscribe only to the thesis that meaning determines type reference. each such representation will predict the same synonymy relations, etc.contrary to the indeterminacy thesis-and hence such representations can be regarded as notational variants. If synonymy is thus definable, and hence we have a criterion of propositional identity, there is a fact of the matter about questions of meaning and translation.
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In subscribing to this thesis, we are bringing type reference under grammar: type reference is a matter of semantic competence while token reference is a matter of performance. One remark about the mechanics of bringing type reference under the grammar's account of meaning: this requires, as part of the grammar's account of semantic competence, principles that map from semantic representations of senses onto conditions for type referents. These principles will include traditional principles like the principle that something is a referent of an expression e just in case it falls under the concepts which constitute the meaning of e. This leaves us with the explanation of how token reference works and the role type reference plays. This explanation is the last step in explaining how the conditions of reference can be fixed in advance. Token reference is not fully determined by meaning; it is a matter of performance because it is a function of extragrammatical information from the speech context as well as grammatical information from the language. Thus, an account of how token reference works will be a psychological model of how speakers exercise their semantic competence, relative to extragrammatical information, to connect utterances with the things to which they refer. The only plausible model I know claims that token reference works like heuristic programming: speakers token refer on the basis of heuristic strategies exploiting their extragrammatical or encyclopedia information but under the control of fail-proofprocedures exploiting their semantic competence. Why did God equip us with such strategies? Why weren't conditions for type reference enough? The conditions for type reference, typically, are too abstract to meet the practical demands of language use. For example, the meaning of "physician" in English is something like "one who has earned the degree of doctor of medicine." But such a referential condition would be difficult to apply in most situations. Accordingly, languagausers require a way of expediting reference and this they get by using a heuristic strategy that identifies physicians on the basis of the stereotype that physicians wear white jackets with prominently displayed stethoscopes. Such strategies not only enable the speaker to refer quickly and easily but they run a minimal risk
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of error because the extragrammatical information employed in such a heuristic strategy can be evaluated for validity as a criterion for picking out the desired objects. That is, information is selected only if there is a high probability that, relative to the class of situations where the strategy is needed, the information will pick out objects in the type reference. Though misidentifications like identifying an actor on location wearing a white hospital jacket as a physician can occur, if the use of strategies is restricted to situations in which the aforementioned probability is high their occurrence is rare enough to make the risk worthwhile. We have now explained the notion of fixing the conditions of reference in advance: the entire theories of semantic competence and performance are required to plug the gap in the traditional intensionalist position. Let us now return to Putnam. His claim, we recall, was that what one would naturally say about certain hypothetical cases is inconsistent with intensionalist views about analyticity. The claim is based on alleged counterexamples, all of which are variants of Putnam's original robot-cat case. Putnam's argument for the claim is this: Cats could turn out to be r~bot:spy devices that look and behave like animals; consequently, the sentence "Cats are animals" cannot be analytic, since if it were, cats could not turn out to be robots. This argument, whether formulated in terms of robot cats, organic pencils, or machine trees, can easily be turned back on Putnam. If the sentence "Cats are animals" is analytic, then no robot can be a cat because it is impossible for a genuine cat to be anything but an animal. But the force of so turning Putnam's argument back on him depends on the position of the person doing the turning. If this position is the one that Kant, Frege, C. I. Lewis and their contemporary followers take, the counterargument has little force. For, as Donnellan pointed out, this position has no account of the difference between a priori and a posteriori criteria for applying expressions. Thus, someone with this position has no way to anchor the claim that "cat" has its reference fixed a priori .by a criterion that requires its referent to be a n animal. There is no distinction between the sentence "Cats are animals" turning out not to be analytic and people's referential uses of "cat" turning out to be references to nonanimals. 346
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However, the counterargument has great force if made from the position developed immediately above. On this position, there is an account of what it is to fix the conditions for reference in advance, and hence an account of the difference between a priori and a posteriori criteria. Appealing to this account, in particular, to (C,) and the semantic theory underlying it, we have grounds for determining the analyticity of a sentence that are independent of what previous uses of "cat" referred to. The analyticity of "Cats are animals" is a matter of whether or not the judgments of speakers about the structure of sentences in which "cat" and "animal" occur are best explained by semantic representations of "cat" and "animal" on which the concepts in the meaning of "cat" include the sense of "animal." The grounds on which (C,) determines analyticity concern the internal structure of sentences. This means that the conditions of reference for words like "cat" and "animal" and the truth conditions for analytic sentences like "Cats are animals" are fixed in the same way as are the conditions of reference for quantifiers like "all" and "some" and the truth conditions for logical truths like "If someone is not happy, then not everyone is happy." The conditions for logical truths are fixed a priori because they are determined on the basis of judgments about the structure of sentences rather than on the basis of experience (that is, the absence in experience of cases in which someone is not happy but everyone is). The conception of meaning and reference outlined above puts the fixing of the conditions for reference and truth in connection with analytic sentences on the same footing: the conditions for a sentence like "Bachelors are unmarried" are fixed a priori because they, too, are determined on the basis of judgments about the structure of sentences rather than experience (that is, the absence in experience of married bachelors). Thus, the force of our reply to Putnam is like that of a reply to the claim that a logical truth might be false: Putnam's claim must be false because it is inconsistent with a necessary truth. Either "Cats are animals" is analytic or not-on purely grammatical grounds. If it is synthetic, there is no issue. But if it is analytic, then, even though the objects to which speakers have been referring turn out to be robot spy devices, the sentence is
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true. Such objects are not cats: it is impossible for something to be a genuine cat and not an animal because the condition for being an animal is included in the condition for being a cat. A claim that something is a counterexample to "Cats are animals" must be false just as a claim that some statement is a counterexample to "No statement is both true and false" must be false. How could people all along have referred to robot spy devices with "cat" when ex hypothesi "cat" means "feline animal"? The explanation is simple: such uses are references under a ~ ~ token references are in no false (semantic) d e ~ c r i p t i o n .Such essential way different from those that Donnellan counts as reference under a false description: in both sets of cases, the conditions for reference determined by the meaning of an expression are not satisfied by the object to which a use of the expression refers. 44
The failure of the serious arguments against a language/ theory distinction not only frees us to employ this distinction but suggests the proper way in which to draw the distinction. In a nutshell, it is this: something is a matter of language in connection with an expression e (leaving phonological and syntactic matters aside) just in case it is represented in an optimal semantic representation of e. Something is a matter of theory in connection with e just in case it is not represented in a n optimal
"'See Donnellan, K. '(Reference and Definite Descriptions," The Philosophical Review, Vol. LXXV, No. 3, 1966, pp. 281-304. "Reference under a false description is simply the case where the token referent(s) of a n expression is not iddntical to the-type referent(s) of that expression. We might similarly reconstruct the ordinary language philosopher's notion of a standard use as a reference under a true description, that is, as the case in which the token referent(s) is in the type reference of the expression. This, in fact, reconstructs only the portion of the notion of standard use that concerns acts of reference. T h e othkr portions which concern acts of stating, requesting, etc. can be easily encompassed by changing the explication to the condition that reference be under a true description and further that utterance meaning and sentence meaning match in propositional type and content. See Katz, J. J. Propositzonal Structure and Illocutionary Force, T . Y. Crowell, Harper & Row, Inc., New York, 1977.
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semantic representation of e but is essential to stating the laws that explain the behavior of the referent(s) of e. Given defi~itions of analyticity and syntheticity in semantic theory,45this implies that matters of language in connection with e are expressed in the maximal set of analytic sentences in which e is the subject, while matters of theory in connection with e are expressed in the synthetic sentences containing e that state the laws for the domain in which e's referent(s) falls. We are now in a position to set out the implications of the language/theory distinction for conceptual change in science. Logical empiricists defended the existence of meaning invariance or translatability through any theory change on the grounds that the meaning of all theoretical terms derives from a common observation vocabulary. The logical empiricists thus linked the fate of meaning invariance to the fate of their theoretical/observational distinction and their program of grounding meaning in experience. Accordingly, when both the distinction and the program collapsed, it seemed, in the context of skepticism about the language/theory distinction, as if the thesis of meaning invariance too had collapsed. It was a short step from the apparent collapse of meaning invariance to the doctrines of the new philosophers of science on conceptual change. The language/theory distinction keeps these controversial doctrines from getting off the ground. If we make this distinction, the collapse of the logical empiricist's basis for meaning invariance no longer leads directly to the doctrines of the new philosophers of science. Meaning invariance can be based on the common semantic structure of languages instead of the common observational vocabulary of theories. Thus, the new philosophers of science fallaciously infer that, since the logical empiricist doctrine that terms gain their meaning from experi' Q u i n e voiced a traditional and well justified complaint against Kant's formulation of analyticity: "This formulation has two shortcomings: it limits itself to statements of subject-predicate form, and it appeals to a notion of containment which is left a t a metaphorical level." From a Logical Point of View, p. 21. Both deficiencies are overcome when the formulation of analyticity is made the explicandum for one of the definitions in semantic theory. See Semantic Theory, pp. 171-182.
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ence is inadequate, the Duhemian doctrine that terms gain their meaning from theories is the only alternative. T h e existence of a semantic theory of the kind described above not only enables us to make this logical criticism of the new philosophy of science, but, in suggesting this alternative basis for meaning invariance, it enables us to replace the empiricist metaphysics of logical empiricism with the rationalist metaphysics of the Cartesian tradition underlying semantic theory and the Chomskian framework. When we make this replacement, we obtain the following conception of the metaphysics of meaning invariance: meaning invariance results from the fact that terms gain their meaning from a n innate system of meanings underlying all natural languages; each natural language correlates these meanings with the members of a distinct set of sentences. T h e same theory is expressible in different languages because the sentences of a language provide different sets of sensible signs for these universal meanings. Different theories are expressible in the same language because the grammatical principles of correlation and sentence formation of a language are, in principle, capable of producing the synthetic sentences to state the laws and explanations that characterize different theories. We now come to the new position on conceptual change in science that I promised at the beginning of this essay. I will call the new position "linguistic rationalism." "Rationalism," because the position has its roots in the Cartesian tradition and maintains that the conceptual structure underlying our knowledge comes not from experience, as logical empiricism claimed, but from the innate conditions for such knowledge. "Linguistic," because the position stresses the application of linguistic theory to philosophical questions similar to the way logical empiricism stressed the application of logical theory to them. I will develop the exposition by enumerating and explaining further differences between linguistic rationalism and logical e m p i r i c i ~ m . ~ ~ uLinguistic rationalism's conception of the philosophy of science differs from logical empiricism's in two further respects. First, it rejects the latter's metascience conception of the philosophy of science. Underlying this conception is, I think, another facet of their confusion of .language and theory.
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The general difference in outlook between these positions is that linguistic rationalism emphasizes the continuity of linguistic and rational processes from everyday thought to scientific thought, whereas logical empiricism had emphasized the discontinuity of such processes. It viewed scientific progress as a struggle to liberate us from prescientific modes of thought. Linguistic rationalism sees scientific progress as a refinement of everyday thought processes. T h e difference in outlook leads to concrete differences on a number of philosophical issues. The attempt on the part of Frege and his logical empiricist followers to construct a logically perfect artificial language is a case in point. Frege and the logical empiricists believed that natural languages are riddled with imperfections, such things as ambiguities and failures of grammatically well-formed expressions to have a referent. Because such "imperfections" mislead reasoners, Frege and the logical empiricists held that natural languages were ill-suited for doing science and proposed to replace them with a n artificial language designed to be a perfect instrument for science. ~ ~ the Linguistic rationalism agrees with W i t t g e n ~ t e i n on T h e metascience conception identifies the enterprise of explicating the logical form of scientific propositions with the enterprise of explicating the methodological notions and principles used in science. ~ i n g u i s t i crationalism sees these as distinct. Explication of the logical form of scientific sentences, as is implied by the discussion in the text, is simply a part of the task of explicating the logical form of sentences in the natural language. Explica.tion of scientific methodology, on the other hand, is not a matter of better understanding language but a matter of better understanding the theory construction faculties we bring to the organization a n d interpretation of ordinary and scientific experience. As a corollary, linguistic rationalism denies that there is any special technique for overcoming philosophical difficulties of the sort that logical empiricists recommended under the title "reformulation" or "reconstruction." (See Maxwell, G. & Feigl, H. "Why Ordinary Language Needs Reforming," The Journal of Phzlosophy, Vol. LVIII, 1961, pp. 488-498.) As we made clear in the text, natural language has no faults and so reform is uncalled for. As suggested just above, the methodological problems arising in connection with notions like 'law.' 'theorv.' , , 'confirmation.' 'sim~licitv.' ,, etc. cannot be solved with a better understanding of language' because we d o not want to know what "law," "theory," "confirmation," "simplicity," etc. mean in English but what law, theory, confirmation, simplicity, etc. are. W h a t is required is a more sophisticated epistemological theory, not a more sophisticated grammar of English. " Wittgenstein, L. Philosophical Investzgatzons, Basil Blackwell, Oxford, 1953. L
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adequacy of natural languages and the status of artificial languages (though not, of course, on the value of philosophical theories). It sees no grounds for taking such things as ambiguities or non-referring expressions to be imperfections. A fallacy stemming from the wrong step at an ambiguity or a plunge into a truth value gap is no more the fault of the language than an unwary hiker's wrong turn at a fork in the road or fall into a depression is the fault of the terrain.48Linguistic rationalism does not blame the hammer when its user hits a finger instead of the nail. To linguistic rationalism, the entire quest for a logically perfect language is simply a confusion between language and language use. This is not to deny the usefulness of artificial languages, but only to conceive of their role in science differently. First, linguistic rationalism denies that the role of artificial languages is to create a demarcation between everyday thought and scientific thought. Rather, artificial languages are viewed as extensions of the expressive side of natural languages, bound by the same constraints as natural diachronic processes. The power of artificial languages to express propositions is acquired from natural language, as can be seen from attempts like Carnap's to construct relatively comprehensive artificial language^.^' It comes from the parasitic relation between an artificial language and the natural language used to explain it. Artificial languages are extensions of natural languages which exploit abbreviatory definition. They provide a high level of precision in some area of the vocabulary of the natural language without the prolixity that would otherwise be the price paid for such precision. There is, in principle, no reason why mathematics could not be done with English expressions like "the ratio of the circumference of a circle to its diameter" instead of formal symbols like "T." Beings with perceptual and intellectual faculties "far superior to ours," who would not
For further discussion, see Katz, J. J. "The sentation," Erkenntnzs, Vol. 13, 1978, pp. 69-72. 49Carnap, R. "Foundations of Logic and Encyclopedia of Un@ed Science, Vol. I , Nos. 1-5, Press, Chicago, 1955, pp. 143-213, particularly, tion.
Theory of Semantic RepreMathematics," International The University of Chicago the treatment of interpreta-
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find such prolixity a hindrance, would have no notational preference. 50 Second, linguistic rationalism denies that the role of artificial languages is to create a demarcation between science and metaphysics. It rejects the claim of Hempel and others that the criterion for meaningfulness is translatability into a logically perfect language-otherwise known as an "empiricist language."" Linguistic rationalism instead proposes the criterion that meaningfulness is expressibility in a meaningful sentence of a natural language. We know that a sentence is meaningful by knowing that it is one to which an optimal grammar of the language assigns a semantic representation. Thus, to determine what is meaningful, we construct grammars-theories of a languagel-not artificial languages. Third, linguistic rationalism questions the adequacy of the apparatus for representing the logical form of sentences in natural languages that philosophers of science have taken over from the tradition of logical theorizing in connection with artificial languages. This apparatus is adequate only if the postulational approach in this tradition can, as Carnap thought in suggesting the use of meaning postulates, be extended, with no essential change in the apparatus, to deal with the aspects of logical form contributed by the meanings of words generally. I have argued elsewhere5' that the apparatus is inadequate because it treats nondeductive meaning relations in the logical 50 I am suggesting that a concept like a is at the apex of a definitional pyramid where at each level the concepts appearing at the preceding level are expanded. The pyramid rests on a foundation of conceptual primitives, about which I will have more to say in the text below. Thus, in the example, the notion of circumference will be expanded as something like the external boundary of a figure. ""Problems and Changes in the Empiricist Criterion of Meaning." The following question never comes u p in discussions (like Hempel's) of translatability into a n empiricist language as a criterion of meaningfulness: how d o we know that failure to be able to translate a sentence into such a language is not a sign of the inadequacy of such languages rather than a sign of the inadequacy of the sentence? Why shouldn't failure of translation not be taken as failure of the empiricist assumptions underlying the constraints on such languages? j2 Katz, J. J. "The Advantages of Semantic Theory over Predicate Calculus in the Representation of Logical Form in Natural Languages," New Directions in Semantics, The Monist, Vol. 60, No. 3, 1977, pp. 380-405.
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form of sentences as if they were deductive in nature. Two harmful effects on the philosophy of science of this mistaken treatment will illustrate the broad relevance of linguistic rationalism for this subject. Many philosophers of science have said that the traditional conception of logical structure implies, as Cohen and Nagel put it, that "all science is circular."53 Some philosophers of science, like Cohen and Nagel themselves, claim that there is nothing wrong with arguing in a circle providing the circle is too big to escape. But this is like saying that there is nothing wrong with cancer providing carcinogens are too prevalent to escape. Others, like Campbell, take a n even more drastic way out, claiming that "no question of deducing one law from another" arises in science, that "all the so-called laws of science [are to be regarded as] one single law which is always being extended and refined."54 Linguistic rationalism offers a much more plausible solution. It introduces new apparatus to handle nondeductive logical relations. This apparatus characterizes a notion of analytic implication in which the conclusion expresses nothing more than what is in the logical form of the premiss. As a byproduct, linguistic rationalism enables us to define "circular argument" as a n argument whose conclusion is analytically implied by its premiss. The definition is broad enough to cover genuine petitio principii but narrow enough to exclude logical deductions: linguistic rationalism says that science can be deductive without being circular. 55 The second illustration is of the way in which artificial language doctrines encourage fallacies in philosophy of science. The case I have in mind is Campbell's claim that meaning in science is only a contingent matter dependent on particular laws. Campbell writes the use of certain words implies the assumption that certain laws are true, and
- . .. ""Cohen, M. R. and Nagel, E. Introductzon to Logzc and the SczentEf2c Method, Harcourt, Brace, & Co., New York, 1934, p. 379. "Campbell, N. R. W h a t is Science? Dover Publications, Inc., New York, 1952, p. 47. " Paradigmatic cases of the petitio przncipii are examples like that in Copi, I. Introduction to Logic, T h e Macmillan Company, New York, 1961, p. 65.
SEMANTICS AND CONCEPTUAL CHANGE that any statement in which those words are involved is without any meaning whatever if the laws are not true."
Campbell's grounds for this are that Every statement which we make about forces involves the tacit assumption that the laws of dynamics are true; without that assumption a statemer.t such as that made in Hooke's Law would be neither true nor false; it would be simply meaningless. 57
But these grounds are sound only if the account in the traditional conception of logical structure of the relation between statementhood and meaningfulness-the account Russell gives correct for natural languages. in his theory of description~~~-is Thus, the argument of Strawson and others5' that in natural languages, unlike Principiaese, the conditions for a sentence to be meaningful are distinct from the conditions under which it is true or false exhibits the fallacy in Campbell's argument. I will mention one further philosophical difference between linguistic rationalism and logical empiricism. It concerns thelogical empiricist's answer to the Kantian question of how synthetic a priori knowledge is possible in mathematics. Logical empiricists claim to have shown that empiricism can escape the traditional rationalist criticism that empiricism cannot account for a priori knowledge in mathematics and logic. They argued on the basis of Frege's work that mathematics is logic and logic nothing more than analyticities grounded in semantic stipulation (which can be known through experience). The first point to note is that Frege did not actually demonstrate that mathematical truths translate into logical truths and logical truths are analytic truths. The latter part of his "demonstration" turns out to be a piece of epistemological sleight of hand: Frege begins with the Kantian notion of analyticity but
Foundations of Science, p. 42.
Ibid., p. 42.
58 Russell, B. Introduction to Mathematical Philosophy, George Allen & Unwin,
Ltd., London, 1919, pp. 167-180. Strawson, P. F. " O n Referring," Mind, LIX, No. 235, pp. 320-344. Katz, J. J. Semantic Theory, Harper & Row, Inc., New York, 1972, pp. 136-150 a n d Katz, J. J. "A Solution to the Projection Problem for Presupposition," in Syntax and Semantics, Vol. 11: Presuppositzon, Choon-Kyu O h & David A. Dinnen, eds., Academic Press, Inc., jn press. j6
57
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immediately switches to his own notion of deduction from logical axioms and definition^.^' Frege diverts our eye by remarking that he does not "mean to assign a new sense to these terms" [i.e., "analytic", "synthetic", "a priori", "a posteriori"] "but only to state accurately what earlier writers, Kant in particular, have meant by them"; then, on the next page, Frege does assign a new sense to "analytic truth," namely, as "a truth deducible from general logical laws and definitions but without assumptions taken from the sphere of a special ~cience."~' The second point*to note is that linguistic rationalism shows how to separate meaning relations and deductive relations, thus blocking the empiricist's attempt to escape the criticism. Linguistic rationalism is based on a grammatical explication of Kant's notion of analyticity. This explication overcomes Frege's criticism of Kant's notion, viz., that Kant's notion applies only to subject-predicate sentences, as well as others such as the criticism that Kant's notion appeals to an inherently metaphorical concept of containment. The explication generalizes Kant's notion so that it applies to subject-predicate sentences and relational sentences equally (stating the generalization in terms of a formally defined notion of inclusion). The generalization reveals that Frege's notion of analyticity is not simply an extension of Kant's notion that avoids its "narrowness," but an entirely different concept, as different from Kant's as the containment of "plants . . . in their seeds" is different from the containment of "beams . . . in a Since Frege's argument for the analyticity of logical truths fails, the logical empiricist no longer has a response to the criticism that empiricism cannot account for a priori knowledge of mathematical truths. The grammatical explication of Kant's notion shows that the Kantian notion of analyticity applies only to language while the Fregean notion applies only to (logical) theory. Thus, the explication shows that the logical empiricist's response to the criticism of traditional rationalism is another example of the confusion of language and theory. 64 Semantic Theory, p. 119. The Foundations of Arithmetic, pp. 3e-4e. '"emantic Theory, pp. 17 1-181. 63"The Advantages of Semantic Theory over Predicate Calculus in the Representation of Logical Form in Natural Languages"; also, Smith, G. & Katz, J. J. "Intensionally Admissible Models: The Extensional Interpretation 60
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Change of meaning in science occurs in both of the ways change of meaning occurs in diachronic processes outside science. Some changes emerge in the historical process of scientific development, and others result from stipulations, explicit or implicit, on the part of a particular scientist or scientists. The term "geologist" provides an example of the former change of meaning. Geologists today study the moon. The term now means something like "scientist who studies the solid matter of a celestial body". Examples of the changes or differences that result from stipulation are found in disputes like the one over whether Newton and Einstein meant the same thing by "mass". Linguistic rationalism provides a definition of change or difference in meaning that covers both cases: (C ,)
An expression e changes its meaning from stage t i to stage t , of a language just in case the optimal semantic representation of e at t i makes a different prediction about a semantic property or relation of e than does the optimal semantic representation of e at t ~ .
This criterion of semantic difference together with the account of type and token reference developed above can help to clarify important controversies in the history and philosophy of science about when two scientists mean or refer to the same thing with a common term. Let me take an example from the controversy between the old and new philosophies of science. In a famous passage from The Structure of Scient2ftc Revolutions, Kuhn raises the following objection to the claim that Newtonian dynamics follows from Einsteinian dynamics: The physical referents of these Einsteinian concepts are by no means identical with those of the Newtonian concepts that bear the same name. (Newtonian mass is conserved; Einsteinian is convertible with energy. . . of Intensional Semantics," in preparation This point goes back to Katz, J. J. "Some Remarks on Quine on Analyticity," The Journal ofPhilosophy, Vol. LXIV, No. 2, 1967, pp. 51-52. " The Structure of Scientific Revolutions, pp. 100-101.
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Shapere, in his review of Kuhn's book, replies, one might equally well be tempted to say that the "concept" of mass (the "meaning" of "mass") has remained the same (thus accounting for the deducibility) even though the application has changed.66
Shapere goes on to comment, The real trouble with such arguments arises with regard to the cash difference between saying, in such cases, that the "meaning" has changed, as opposed to saying that the "meaning" has remained the same though the "application" has changed. ''
Linguistic rationalism provides a general framework within which to answer such questions. The scientist makes a choice, explicitly or inlplicitly, as to what senses theoretical terms will have and what propositions will be expressed by the synthetic sentences chosen as postulates. If the scientist makes an explicit choice but is unclear about it, or makes an implicit choice, there can be a question about the meaning of the term. In this case, semantic theory characterizes the evidence that bears on the question of its meaning: semantic theory specifies the "cash difference" in terms of the definitions (C ,), (C ,), and (C ,). These apply equally to the scientist's idiolect and to the language. Given then, that we can, in principle, decide what "mass" meant to Newton and Einstein, were they talking about the same thing? The conception of reference in terms of a dual system with a semantic fail-proof procedure and encyclopedic strategies brings to light an equivocation between whether "talking about" is glossed as "type referring" or as "token referring." I will first consider the case where "talking about" is glossed as "type referring." In that case Newton and Einstein were talking about the same thing if "mass" had the same meaning in both their idiolects. If "mass" had different meanings in their idiolects, they could still be talking about the same thing if the two senses have the same extension. Suppose, for example, Newton's "mass" means "the aspect of a body that determines its inertial behavior" and Einsteiu's, means "the 66 Shapere, D. "Review of The Structure of Scientific Revolutions," The Philosophical Review, Vol. LXXIII, 1964, p. 390. Ibid., p. 390.
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aspect of a body that determines the gravitational force acting on it from the stars and galaxies in the universe." If we then find out that one and the same aspect of a body determines its inertial behavior and the gravitational force acting on it from the stars and galaxies, Newton and Einstein were talking about the same thing but making different empirical claims about it. If we find out that these terms have different extensions then Newton and Einstein were not talking about the same thing. I now consider the case where "talking about" is glossed as "token referring." Here we are asking w@ther certain specific uses of "mass" on the part of Newton and Einstein picked out the same thing. Now knowing both the meaning of "mass" in their idiolects and knowing about the relevant facts about the physical world no longer suffices to answer the question. The obstacle is possible divergence of their referential strategies. Coreference of Newton's and Einstein's use of "mass" depends on such things as whether their respective beliefs that mass is conserved and that mass is convertible appear as necessary conditions on the token referent in the strategies on which the uses in question were based. It might be that Newton's "quantity of matter" conception of mass was a n encyclopedia account while his inertial conception was definitional. 68 Even though it may be extremely difficult or practically impossible to actually determine the historical facts of the matter in one of these cases, particularly in the case of token reference, the analysis provided by linguistic rationalism sustains Shapere's reply to Kuhn and clarifies what it might mean for scientists to be talking about the same thing. VII What is conceptual change according to linguistic rationalism? It is not change of meaning in the sense of (C ,). Change of meaning is merely a n alteration in the correlation of senses in the semantic repertoire of the language with expressions and
"
See Koslow, A. Changes in the Concept ofMass, jom Newton to Einstein, Ph.D. Dissertation, Columbia University, 1965, pp. 52-92.
JERROLD D. KATZ
possible expressions of the language. Conceptual change has to do with the development of new and better scientific concepts. To see what notion of conceptual change linguistic rationalism has, recall that linguistic rationalism does not just claim that the linguistic system underlying science is continuous with that in everyday life. It also claims that the rational processes underlying theories in science are continuous with those that produce the ordinary explanations of everyday life. It claims that the sophisticated scientific practices of statistical confirmation, concept formation, and theory construction are prefigured in the methodology underlying such things as the entrenchment of encyclopedia information used in strategies of token reference. The ability to make correlations and judge significance which is required to determine that a property like "wears a white jacket with prominently displayed stethoscope" can function heuristically to identify physicians is the precursor of sophisticated abilities in statistical confirmation. The ability to construct a concept, stereotype, or prototype that links and unifies diverse encyclopedia information is the precursor of sophisticated abilities in concept formation. The ability to form common sense explanations of why there should exist the empirical co-occurrences on which the linking of diverse encyclopedia information rests is the precursor of sophisticated theory construction and model building. We can thus treat conceptual change generally, and, in line with what we said above about the difference between matters of language and matters of theory, we can characterize conceptual change as, typically, the replacement of one set of explanatory principles with the concepts c,,, . . . , c, by another set with the concepts c',, . . . , c', in the belief that the new concepts in c',,, . . . , c', enable the replacing principles to better explain the phenomena. We can now distinguish change of meaning from conceptual change and both from scientific change in general. Meaning change occurs when an expression of a language which is correlated with a particular concept or sense at one time is no longer correlated with it at some later time. The expression may lose meaning altogether, or may become associated with a new sense.
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If meaning change occurs, then scientific change must occur, with or without conceptual change. Now consider a scientific theory whose postulates are the synthetic propositions PI,. . . , P,, each composed of a particular set of concepts. Scientific change occurs when PI,. . . ,P, are replaced The conby a different set of synthetic propositions Q,,. . . , cepts from which Q,, . . . , Q,,. are constructed may or may not contain only concepts originally appearing in PI . . . , P,. If the same concepts are used, but in different propositions, conceptual change will not occur. The theory makes different statements but neither enlarges nor reduces the stock of concepts on which it originally drew. Conceptual change is the special case of scientific change that occurs when construction of the new postulates Q,, . . . , Q, requires new concepts that did not figure in the original theory. Thus, scientific change may or may not involve conceptual change. Finally, scientific change with or without conceptual change may or may not be accompanied by change of meaning, since one of the terms of one of the synthetic sentences expressing a postulate of the theory may or may not become correlated with a new concept. If meaning change takes place and the new concept is drawn from the set of concepts comprising the original theory, only scientific change takes place. If it is drawn from outside the theory, conceptual change takes place. Scientific change takes place without meaning change if the theory's postulates are changed without any of the terms in the theory becoming associated with a different (or no) sense. Conceptual change takes place without meaning change just in case none of the terms in the original theory loses its original sense and a new term from outside the theory is introduced as part of the new theory. Such replacement involves two steps, a step of conceptual innovation and a step of principle evaluation. Linguistic rationalism has something original to say only about the step of conceptual innovation, but it casts some familiar points about the step of principle evaluation in the old and new philosophies of science in a new light. Accordingly I will discuss linguistic rationalism's position on conceptual innovation in some detail and return briefly to principle evaluation at the end.
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JERROLD D. KATZ
If we combine linguistic rationalism's conception of the continuity of linguistic and rational processes from everyday thought to scientific thought with the conception of the acquisition of knowledge in the Cartesian view that provides the rationalist underpinnings of the position, we are led to a conception of the source of the concepts in conceptual change in science and of the nature of the process of change that is radically different from the prevailing accounts in the old and new philosophies of science. Linguistic rationalism claims that all the concepts available to science and everyday explanation are contained in the innate space of possible senses with which humans face the task of language acquisition. The notion of an innate space of possible senses is to be understood in the context of Chomsky's now familiar Cartesian position on language acquisition. Chomsky argues that only a theory of acquisition that posits innate grammatical principles rich enough to specify the set of all possible grammars can account for the fact that normal children learn the immensely complex structures of a natural language quickly, uniformly, and on the basis of highly degraded samples of speech. O n our view, the posit of such innate grammatical principles includes semantic principles that specify the space of possible senses. Further, the notion of all concepts being contained in this space is to be understood in the sense in which an infinity of theorems is contained in a finite set of axioms. The innate semantic principles include a finite set of primitive senses which provide the stock of elementary concepts and also operations for compounding primitive senses to form any complex concept. Linguistic rationalism's conception of the nature of the process of conceptual change is the following. A problem of conceptual change arises when it is suspected that a set of explanatory concepts is inadequate. The development of explanatorily better concepts requires, on our view, locating such concepts in the innate conceptual space. This means that the scientist has to construct a not yet assembled concept from the elementary concepts (and those that have already been assembled) using the appropriate compounding operations. The construction has to produce the right concept, that is, one that is better for the scientific job at
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hand. Hence, the construction must be carried out under the guidance of "assembly instructions" that provide the necessary subset of elementary concepts and a suitable sequence of combinatorial operations. Thus, the nature of the failure of the original concepts has to be analyzed in a way that provides such assembly instructions. 69 It must be stressed that there is no denial of novelty here. The stock of primitive senses and the combinatorial operations specify the infinite possibilities in our conceptual potential recursively, and so linguistic rationalism denies that any concept comes ex nihilo. This, I take it, is a good thing to deny. But this denial is not a denial of novelty in concept formation. T h e claim that our conceptual potential is limited to the infinite possibilities in our innate conceptual space no more denies the prospect of novel concepts than the claim that the syntax potential of a speaker is limited to the infinitely many grammatical sentences denies the prospect of novel sentences. Both in the case of concepts and in the case of sentences, the claim is only that novelty is rule-governed: new constructions not resembling already known
'' I should point out also that there is to my knowledge, no alternative account of concept formation. Empiricist accounts are not even possible. T h e argument showing this has been presented by various rationalistically inclined philosophers (Katz, J. J. The Philosophy of Language, Harper & Row, Inc., New York, 1966, pp. 216-266; Fodor, J. A. The Language of Thought, T . Y. Crowell, Harper & Row, Inc., New York, 1975, pp. 55-97). O n my own version of the argument, Goodman's grue paradox is turned on the empiricism he espouses. Suppose a concept is not definable within the set of innate primitive senses and hence not constructable by the operations for forming compound concepts. Such a concept must be acquired from a finite sample of its instances, but, by the grue-argument, any sample projects indefinitely many incompatible concepts, and by the fact that ex hypothest there is no way to relate the concept in question completely to the primitives and make simplicity com~ a r i s o n srelative to the o ~ e r a t i o n sof construction. there is no wav to narrow down the indefinitely many incompatible concepts consistent with the sample to one. (See my "Simplicity," in preparation.) Note, finally, that Goodman's own theory of entrenchment, apart from its many other woes, cannot come to the aid of his empiricism, since this theory only applies on the illegitimate assumption that some body of empirical statements is well enough inductively confirmed to serve as a basis for the initial uses of entrenchment. The question is how these statements got confirmed without some prior body of statements. The answer is they couldn't have on pain of infinite regress.
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constructions are nonetheless logically contained in our tacit rules for them. Such rule-governed novelty is, moreover, compatible with absolute creativity in actual processes of analyzing problems, constructing concepts, and assessing their adequacy for the scientific job at hand. VIII Linguistic rationalism preserves what is of value in both the new and the old philosophies of science. What is of value in the new philosophy of science is not its philosophical doctrines but its sociological doctrines. Loose as Kuhn's notion of a paradigm is, it, together with Kuhn's distinction between revolutionary and normal science, contains genuine insights about the sociological processes at work in the development of science. These are not philosophical insights about how scientists ought to conceive of the scientific method, but socio-historical insights about how they often do conceive of it in practice. Kuhn's account of the tendency of research during periods of normal science to confine itself to an established paradigm that poses specific problems for future investigation, channels research to them, influences the selection of data and hypotheses, and so on expresses an important truth about what goes on in normal scientific practice. Also, Kuhn's account of the centrality of paradigm replacement to scientific revolution expresses an important truth about what goes on in scientific transitions. There is no obstacle to the acceptance of these insights so long as they are not thought of as bound up with philosophical doctrines such as the relativity of meaning and the indeterminacy underlying the non-cumulative conception of scientific development. What is of value in logical empiricism are two things: the conception of cumulative progress in science based on a universal scheme for interpreting terms in theories and the conception of theory evaluation as a thoroughly determinate rational process based on methodological canons for judging theories against evidence. Linguistic rationalism incorporates these conceptions into its own framework by providing a rationalist basis for the interpretation of scientific terms and the evaluation of scientific theories. In so doing, linguistic rationalism rescues these concep-
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tions from the criticisms that undermined the empiricist based version of them.
City University of New York
