Chapter 7 TRUTH AND REFERENCE∗ Henri Lauener† University of Bern
To current naturalistic views on philosophy I oppose a...
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Chapter 7 TRUTH AND REFERENCE∗ Henri Lauener† University of Bern
To current naturalistic views on philosophy I oppose a pragmatically relativized version of transcendental philosophy. Quine’s system, as a paradigmatic case, forms a subtle and solidly woven fabric of theses which seem difficult to attack from within in spite of certain apparent tensions. As I am not prepared to concede all the semantic indeterminacies it involves I object to its founding principles and reject naturalism as a general approach. Shunning any notion of absolute (external) truth, I replace the doctrine of physical realism by a distinctive kind of relativism which is not to be confused with so-called cultural or subjective relativism. On the basis of an entirely different conception of language, I consider Quine’s claim that truth precedes reference as an error due to his particular brand of holism and to his one-sidedly behavioristic method. Questions concerning truth are so central in philosophy that it should not be introduced, at the outset, as a pretheoretic notion relying on such a vague criterion as that of assenting to sentences. I doubt that he can be right when he asserts that what objects there are according to a theory is indifferent to the truth of observation sentences, for the meaning, i.e. the intension and the extension of the terms occurring in sentences used for testing that theory, depends on it insofar as their truth, in accord with Tarski’s definition, requires the existence of empirically discoverable objects satisfying the respective open sentences. Therefore, holophrastically conceived observation sentences, held true merely on account of their stimulus meaning, cannot do the job since
∗ This article appeared in the issue of the Revue internationale de philosophie devoted to “Quine with his replies” 1997, vol. 51, pp. 557–566. We thank both the editor of the Revue internationale de philosophie, Prof. Michel Meyer, and Herr Michael Frauchiger acting on behalf of the Lauener Stiftung, for granting us permission to re-publish this paper to which Quine replied in the issue mentioned (Ibid. pp. 581–582)
D. Vanderveken (ed.), Logic, Thought & Action, 153–161. 1997 Revue Internationale de Philosophie. Printed by Springer, The Netherlands.
c
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they do not properly belong to the language in which the theory has been couched. Jaakko Hintikka has distinguished two radically contrasting approaches to language which he labels the universalistic view and the view of language as a calculus.1 According to the first, language is a universal medium which we cannot contemplate from an external vantage point in order to examine its relation to the world. As a partisan of the second approach I do not consider language an amorphous, constantly evolving whole; I rather hold that we create a great number of distinct linguistic systems which we use as instruments for various purposes. Facing the fact that there are different uses of expressions, I lay much weight on the possibility of interpreting or reinterpreting token systems in the way this is done in model theory. According to my method of systematic relativization to contexts (of action), we create reality sectors by employing specific conceptual schemes through which we describe the world. Since a new domain of values for the variables is presupposed for each context I advocate a pluralistic conception of ontology in contrast to Quine who postulates a unique universe by requiring us to quantify uniformly over everything that exists. The divergence comes from the different forms of holism we countenance. In “Two Dogmas of Empiricism”, he favors an extreme sort of holism claiming that our global theory of the world is confronted with the tribunal of experience as a whole and affirming later that only sentences at the periphery have an empirical content of their own. This is so because their (stimulus) meaning — as in the case of all occasion sentences — is constituted by the fact that assent to them is directly prompted in presence of adequate sensory stimuli. Doubts have been raised whether the Duhem-thesis is really compatible with the claim that the meaning of observation sentences does not depend on the theory. With my contextual holism no such difficulty occurs. Rejecting the view of a constantly evolving, unified language-theory, I claim that the intension of all the terms is determined by the axioms of the specific theory with which we operate in a given context, and that consequently the meaning of the observation sentences must depend on that theory, too. Whereas the naturalist aims at theories which are supposed to explain the causal relation between semantic facts and utterances as physical tokens, I stress the normative aspect of semantics. Equating talk about meaning with talk about rules, I consider that intensions and extensions
1 Cf.
“Is Truth Ineffable?”, in Les formes actuelles du vrai, Palermo, 1988, and “Quine as a Member of the Tradition of the Universality of Language”, in R. Barrett and R. Gibson (eds.), Perspectives on Quine, Cambridge (Massachusetts), 1990.
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are fixed by the totality of the rules which prescribe the correct use of the expressions. My method has the advantage that it permits us to distinguish language from theory and to separate the distinctive contributions to the truth conditions made by the language and by matters of fact. If linguistic rules alone are involved we have analytically true statements. Contrary to what Quine affirms, it is not the semantic distinction between analytic and synthetic which is a matter of degree, but the psychological faculty of an individual to comprehend a language. In order to understand exactly the theoretical terms of quantum mechanics, for instance, one must thoroughly master the whole theory including its integral parts of logic and mathematics. Philosophers tend to overestimate the capacities of a layman when they suggest that he can grasp the precise meaning of terms like ’electron’, ’nucleus’, ’spin’ etc. The fact that they are able to utter some true sentences about particles is not sufficient, since full understanding requires potential knowledge of all the truths on the matter — an ideal which can be approximately realized only by professionals. Thus, considered from my transcendental point of view, the very possibility of expressions having meaning depends on conventions, i.e. on a community of users agreeing on a set of rules which determine their use in a context. Insofar as the intensions of the theoretical terms are implicitly defined by the system of empirical laws and their extensions fixed by the intended model, their meaning cannot remain the same in the event of (even a slight) theory change. For, when we give up a theory, replacing it by a new one, the conditions under which sentences can be rightly asserted have been altered altogether so that the two theories must be considered, strictly speaking, as semantically incommensurable. Of course, it is possible, by means of ascent to a meta-language, to speak about the words and to ascertain that they have a similar meaning due to some similarities of the axioms in which they appear, but this does not amount to making them synonymous, since synonymy, according to the present view, must be an intralinguistic property (if it occurs at all). Moreover, we have no obvious guarantee that terms like ’electron’ have the same extension in successive physical theories, contrary to what Hilary Putnam has suggested, because we must secure that equal methods of empirical identification have been applied, before we can assert the extensional identity of two terms used in different contexts. In view of the fact that linguistic individuals cannot be taken to be (identical
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with) physical tokens, as I have argued elsewhere,2 I insist on the different nature of scientific theories dealing with empirical objects and meta-theories talking about abstract linguistic entities. I wonder how Quine with his vision of a unique language-theory manages to keep together such a mixed bag of disorderly things which is fatally threatened — it would seem — by paradox. Therefore, I prefer to resort to my notion of a limited context which allows us to avoid the dismissal of useful semantic distinctions as merely gradual. The resulting concept of meaning diverges radically from any concept developed along naturalistic lines. One important consequence touches on the sentences which are to serve for testing theories. Since a language used in daily matters is subjected to semantic rules differing from those of a language used in science, a sentence taken from the first cannot have a proper function within a scientific test procedure. For this reason the so-called protocol sentences of early logical positivism or Quine’s observation sentences are of no avail when we are confronted with the problem of testing scientific theories. The fact that we may describe, on a meta-level, the words ’water’ and ’H2 O’ as denoting roughly the same substance does not entitle us to declare them synonymous, for they do not belong to the same linguistic systems; as ’water’ is not an appropriate chemical term it should be banished from the language used in the context of chemistry. This explains why I reject sentences like ’Water is H2 O’ as semantically incoherent while I maintain that metalinguistic statements such as, “’Water’ in ordinary language denotes roughly the same substance as ’H2 O’ in chemical terminology”, do make sense. Every philosopher must assume the consequences of his fundamental options. In my case the price to pay is a relativized conception of truth and ontology. Quine, for his part, has become more and more insistent in defending his position of physicalist realism. Yet, somehow surprisingly, he favors, at the same time, an extreme form of ontological relativity, originating in the fact that we cannot determine a speaker’s referential intentions from his linguistic behavior and that, therefore, reference remains empirically inscrutable. But then how is it possible that indeterminacy of reference does not undermine physicalism, the doctrine which assumes the posits of our overall world theory? Quine argues that alternative theories obtained by means of proxy functions are structurally identical with our physical theory down to the observation sentences, through which it gains its empirical content,
2 Cf.
“Speaking about Language: On the Nature of Linguistic Individuals” in A. P. Martinich and M. White (eds.), Certainty and Surface, New York, Edwin Mellen Press, 1992, pp. 117134.
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and that, therefore, they must have the same cognitive import: “The structure of our theory of the world will remain undisturbed, for the observation sentences are conditioned holophrastically to stimulation, irrespective of any reshuffling of objective reference. Nothing detectable has happened. Save the structure and you save all.” The position is clearly stated in the quotation: Since the observation sentences which establish the contact with sensory stimuli are our only access to the one and absolute reality and since they are accepted as true without any regard to referential matters, there can be no objective, i.e. physical, facts about reference. As Quine, on the other hand, concedes that we must ascribe denotations to the terms in order to understand a language he admits a derivative kind of semantic facts in the form of referents which are assumed relative to a background language taken “at face value”. But as such ascriptions are posterior to our attributions of a truth value to sentences we must eventually grant the precedence of truth over reference. It seems very questionable to me whether ontological relativity so conceived is compatible with Quine’s professed realism according to which our physical theory must count as true (pending further information). For if no empirical evidence in favor of the objects posited by the physical theory — inclusively those of physiology, as nerve endings and stimuli etc. — can be adduced, how is it possible to affirm absolutely its (external) truth to the detriment of empirically equivalent3 rivals with platonistic, pythagorean or other ontologies? As I consider any attempt to establish an absolute correspondence relation between theory and reality (neutrally given through sense experience) as hopeless, I am not prepared to accord to physicalism the status of a true theory about the world. It is at best a recommendation to adopt a physicalist ontology on the ground of practical reasons partaking of scientific methodology. Renouncing realism with its dubious notion of external truth and opting for a form of relativism which turns truth into a strictly internal matter, akin to model theoretic treatment, does not prevent me from clinging to an empiricist attitude appropriate to scientific method. Relativity after all is a concept familiar to physicists. Quine’s most implausible theses — especially the ones concerning semantic indeterminacy — have their origin in his deep-rooted conviction that scientific language must be purged of intensionality. Flight from intensions is one of his well-known slogans. As it is impossible to treat intentionality by
3 Two
theories are empirically equivalent if they have corresponding predicates interrelated in the same way and if their corresponding observation sentences are identically conditioned to sensory stimulations, irrespective of the differing kinds of objects they are talking about.
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purely extensional means he adopts a strategy according to which intentions along with propositional attitudes have to be reduced to a strictly descriptive treatment in line with the methods of natural science, particularly of behavioristic psychology which is the seemingly best candidate for being incorporated into our global physical theory. Yet, I doubt that this will do because we cannot be content with simply describing past intentional acts. Ordinary life as well as science requires innovation, i.e. decisions of all sorts in order to achieve tasks which are not predictable by means of a physical theory. My main objection to a naturalistic view on semantics resides in the fact that interpretation presupposes intentional acts to the effect that the members of a community speaking a specific language will agree on a set of rules prescribing the use of the expressions and that it cannot, therefore, be considered as a merely descriptive matter to be handled exclusively with extensional tools. Accepting (conventionally fixed) rules, choosing, conforming, asserting etc. are typical kinds of actions without which language would not exist. If they were absent we could not speak but only produce noises. Consequently there can be no hope for integrating semantics into a physicalist doctrine with its corresponding semantic facts, as long as nobody has succeeded in reducing talk about intensions to talk about extensions. The realist, being committed to the posits of his overall theory, must assume the existence of physical objects and cannot, consequently, justify his claim that it is (externally) true by taking recourse to the pretheoretical truth of some unanalyzed sentences. As we need determinate categories of objects, i.e. definite domains of values for the variables, in order to fix the truth conditions, reference has to play a primordial role. This is the reason why I propose to relativize the concept of truth to contexts in which we operate with specific linguistic systems and theories. According to my normative viewpoint, semantic questions are settled by the fact that we have accepted the rules which determine the intension and the denotation of the terms for a particular language. By relativizing ontology to a given theory we gain the advantage that referential relations become determinate. Thus the analogy with relativity in physics, where position and velocity are determinable relative to an inertial frame, works well while it fails for Quine since relativized reference in his sense cannot be behavioristically determined. The weakness of the naturalist’s position resides in his ignoring the trivial fact that posits presuppose positing and that intentional acts cannot be accounted for in an austerely extensional language as he wants to have it. I conclude then that, notwithstanding his claims to the contrary, reference does matter and that a scientific theory cannot be properly identified without assuming an intended domain whose individuals must satisfy certain
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open sentences in order to make corresponding closed sentences true. At any rate, a philosopher should not resort to the notion of a posit if his very doctrine renders intentional acts of positing unintelligible. According to my special brand of transcendental philosophy, concerned with the optimal conditions for the elaboration of reliable science, we employ specific linguistic systems in order to structure the world about which we acquire knowledge by describing and explaining it with help of various sorts of theories. We create what I call reality sectors by imposing different conceptual schemes on the raw material provided by sensory experience. The imposition of linguistic forms is a precondition for the possibility of individuating objects and for specifying the ontology to which a given theory is committed. Electrons qua electrons do not exist absolutely but only relative to a context in which we use quantum mechanics. Through the selection of a language appropriate to the intended purpose we create a relative a priori such that the truth of certain sentences will be determined by the semantic rules alone. Thus we exclude the very possibility for analytic statements to be refuted by empirical facts (internal to the operating theory) as long as we stick to the same conceptual framework. Such a relativized concept of analyticity depending on linguistic rules explicitly stated in a context has nothing to do with the old absolutistic notion inspired by Kant and rightly dismissed in “Two Dogmas of Empiricism”. It is perfectly compatible with the conviction that no statement is immune to revision. If a conceptual scheme proves to be inadequate for some practical reason we give it up and replace it by a new one. Two tokenwise identical sentences may occur in both contexts, but with different meanings since the connections within the semantic network have been altered, and it can even happen that the one is analytic while the other is synthetic according to the respective sets of accepted rules. As I do not believe that we can do with the continually moving mass of a total language-theory, I insist on the necessity of introducing stability points in our conceptual apparatus by stipulating that certain statements must be held true without regard to empirical matters in the reality sector created by the context. By recommending such a procedure I do justice to the widespread intuition that there are statements whose truth is elucidated without recourse to empirical considerations. Contrary to Quine, I do not rate classical logic as objectively true because we have integrated it into our overall scientific theory. I rather estimate that, being free to make alternative choices, we can use any system that fits best our practical needs. One may prefer, for philosophical reasons, intuitionistic to classical logic and consequently deny the truth of ’p ν -p’. In doing so he does not, however, enter into an objectively decidable
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conflict with his rival who claims the truth of the same (token) sentence. No logical contradiction can arise between the competing positions since the rules fixing the correct use of the connective, i.e. the axioms determining its intension, are not the same. For this reason the meaning of ’ν’ must be different and it should not, therefore, be affirmed that the systems have a common stock of truths. Insofar as no statement of the one can be expressed in the language of the other, they have to be considered incommensurable. My transcendental method requires a uniform treatment of truth by means of modeltheoretic procedures. The difference between mathematics and empirical theories resides in the distinct nature of the denizens who populate their respective ontologies. The domain of the former consists of abstract entities created by the fact that we use a mathematical theory through which they are precisely definable, whereas in the domains of the latter we have physical objects whose existence must be ascertained by way of experimental procedures. Accordingly existential claims like ’(∃x)(x is a pentagon)’ are analytically true in the context of Euclidean geometry since it follows logically from the axioms that there must be at least one individual which satisfies the predicate ’pentagon’.4 On the other hand, synthetic statements like ’(∃x)(x is an electron)’ are true in the context of quantum mechanics because physicists have been able to fix traces of such particles on photographic plates placed in cloud chambers in order to confirm the theory. It may be finally remarked that the theses of a system of logic (whose axioms and rules of deduction determine the intension of the logical constants) remain true under any interpretation of the descriptive terms and that they are, therefore, extensionally indistinguishable. I hope that the reasons I have invoked in the present paper will convince the reader that truth without reference does not make sense. In accord with my transcendental method, I propose to apply the semantic predicate ’true’ only to sentences seen from within a theory, complete with its posited ontology, which we use in a specific context. It seems to me that, in view of the unsurmountable difficulties with which (scientific) realism is confronted, we have no other choice than to banish any notion of external truth. Superseded theories cannot be deemed false in an absolute sense; they only have a more or less extensive range of more 4 For
a platonist believing in the absolute existence of mathematical objects who endeavours to render clear the informal notion of ’arithmetically true’ by resorting to a formal system, there is a problem: as such systems are incomplete according to G¨ ¨ odel’s theorem there will always be truths not captured by them. For me the problem does not arise because, from the start, I limit domains to objects specifiable within an (axiomatized) theory itself specified by an explicit set of rules.
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or less precise applications. Newtonian mechanics, for instance, still works satisfactorily for a limited class of phenomena which we may call classical phenomena. Since it fails in cases where great distances and high velocities are involved, we must use for such domains Einstein’s more efficient theory which, in turn, is not to be termed (externally or absolutely) ’true’ any more than its predecessors. In way of conclusion I remark that ’truth’ is ultimately to be considered as an evaluative term designed to assess sentences with regard to their practical reliability. We can decide objectively whether a sentence used in a given context is true or not only after having accepted rules which fix convenient standards. Thus everything will finally rest on certain agreements about norms which I call conventions and which cannot be captured within a purely descriptive scientific theory, but must rather be discussed and settled by deliberation on a metalevel.