Quine on Holism and Underdetermination

Transcription

1 Quine on Holism and Underdetermination Introduction Quine s paper is called Two Dogmas of Empiricism. (1) What is empiricism? (2) Why care that it has dogmas? Ad (1). See your glossary! Also, what is the contrasting view? It is rationalism, which is not in the glossary. (An overstated or over-drawn difference?) What made empiricism seem desirable? The rise of postulational science in the 19 th century (kinetic theory of matter, Maxwell s electromagnetic fields). The toughest empiricists wanted to eliminate theoretical terms (like the behaviorists in psychology) by defining them in terms of or reducing them to observable terms. Frege s new logic was employed (by the logical empiricists in the first part of the 20 th century) to turn these slogans into precise accounts, but they have not succeeded yet. Popper tried to distinguish real from pseudo-science by the criterion of falsification. The logical empiricists differed from him in two ways. First, they typically thought one could confirm, as well as infirm, a theory. And, second, they tried to demarcate sense from non-sense. A concept or assertion that could not be tied to observation was dismissed as nonsensical or at best (shudder) metaphysical. _ This latter enterprise led to the verification[ist] theory of meaning. Failure of this program is marked in section 5 of Two Dogmas, where Quine calls it reductionism. One popular way to distinguish empiricists from rationalists is their divergent view on the possibility of synthetic a priori knowledge. Here Euclidean geometry was the main prop of rationalists.

2 The general theory of relativity showed that Euclidean geometry (despite Poincaré) was not the geometry of the universe and so not known to be so a priori. (Reichenbach) Pure v. applied geometry. Finally: Einstein s critique of simultaneity seemed to show that real scientific advance could be gotten from thoroughgoing empiricist criticism of metaphysical elements lingering in physical theories. Note: years ago, one might have thought that the sentence: If event e is simultaneous with event f and event f is simultaneous with even g, then even e is simultaneous with event g was analytic. Now, we think it s not well-formed. This is an example (as Duhem foresaw) of a principle that was (nearly) definitional being abandoned for empirical reasons. This leads to wondering whether, even if one could distinguish a class of analytic sentences, the analytic sentences play a distinctive (e.g., a permanent) role in our knowledge. _ This reflection leads to the web of belief view in section 6 of Two Dogmas. Now we re ready for the paper. Section 1. Background for Analyticity Kant s distinction (The predicate is conceptually contained in the subject) is limited to sentences in simple subject-predicate form. That s too limited. A better characterization analytic is true in virtue of meanings and independently of fact. (281) Meaning bifurcates, however. Singular terms have both reference and sense, what they name and what they mean. Else The morning star is the evening star would be as trivial as The morning star is the morning star. General terms, in parallel, have extension and intension. 2

3 But we will not be naïve and think that senses and intensions are things, like references and extensions. We will be sophisticated and ask: when do two distinct terms or sentences have the same meaning (without thinking that there exist things that are meanings for them to have ). So the analytic sentences are, prima facie, those that are truths of logic and those that derive from truths of logic by substituting synonyms for synonyms. An example of the first is: No unmarried man is married. An example of the second is supposed to be: No bachelor is unmarried. Section 2. Definition There are three sorts of definition. 1. Lexicographic relies on pre-existent synonymies, and so can t explain synonymy. 2. Explication Same problem as for lexicographic but in the favored contexts. [Isn t co-extension in these contexts sufficient?] 3. Explicit or Conventional has application limited to formal languages. [Also, for completeness one might mention ostensive and implicit definition, but they do not seem important for the matters at hand.] Section 3. Interchangeability. 1. Interchangeability salva veritate in extensional languages is not sufficient for analyticity. 2. Interchangeability salva veritate in intensional languages containing a necessity operator is sufficient, but necessity presupposes analyticity, according to Quine. 3

4 Section 5. The Verification Theory and Reductionism The verification theory of meaning asserts that "the meaning of a statement is the method of empirically confirming or infirming [disconfirming] it" (292) That is, "statements are synonymous if and only if they are alike in point of method of empirical confirmation or infirmation." (292) This notion of synonymy could be used to define analyticity. But, Quine asks, just "what...is the nature of the relation between a statement and the experiences which contribute to or detract from its confirmation?" (293) He suggests two possibilities. Radical Reductionism: "Every meaningful statement is held to be translatable into a statement (true or false) about immediate experience." (293) Note: it is no longer demanded that there be a term-by-term translation into experiential or "sense-datum" language but rather that sentences as units be so translatable. Carnap, in his Aufbau, tried to turn this slogan into a genuine construction, but failed. He did not even provide a translation for: "Quality Q is at spacetime point (x,y,z,t)". [Counterfactual conditionals seem also to be needed for an adequate translation, but an adequate understanding of (or semantics for) counterfactual conditionals seems to go beyond the resources of a language concerned only with immediate experience. (Nelson Goodman.)] Attenuated Reductionism: "To each [synthetic] statement there is associated a unique range of possible sensory events such that the occurrence of any of them would add to the likelihood of truth of the statement, and there is associated also another unique range of possible sensory events whose occurrence would detract from that likelihood." (295) The root idea here is, according to Q., is "the supposition that each statement, taken in isolation from its fellows, can admit of confirmation or infirmation at all." (295) 4

5 To this "dogma" Quine opposed a generalization of (what we may call) the D- thesis: "[O]ur statements about the external world face the tribunal of sense experience not individually but only as a corporate body." (295) "The unit of empirical significance is the whole of science." (296) The second dogma (reductionism), acc. to Quine, "clearly supports" the first. "[A]s long as it is taken to be significant in general to speak of the confirmation and infirmation of a statement, it seems significant to speak also of a limiting kind of statement, which is vacuously confirmed, ipso facto, come what may; and such a statement is analytic." (295) Section 6. Empiricism without the Dogmas. Opening paragraph states "web of belief" alternative to foundationalism. Note first use of "underdetermination" (in what seems to be a Duhemian vein). Quine throws down the gauntlet. "Any statement can be held true come what may... Conversely...no statement is immune to revision." (297) Quine seems to be asserting that the above courses of action need not lead to inconsistency. (Laudan will think these very weak claims.) Quine would defend these views by citing a generalized version of the D-thesis (what Curd and Cover call "Quine's global version of holism" in fn. 17 on p. 404). One could define two versions of Global Holism: (1) Quinean Global Holism: Each sentence S "meets experience" only together with a set of sentences which is the whole of science. I.e. There is a set of sentences W (the whole of science) such that for every sentence S there is some experientially determinable statement O such that, if (S & W), then O; but it is not the case that if (S & W'), then O, where W' is any proper subset of W. (2) Moderate Global Holism: Each sentence S "meets experience" only together with some set of sentences G, where G in general 5

6 depends on S. I.e., For every sentence S there is some set of sentences G (but which set G depends on the choice of S) and an experientially determinable statement O such that: if S & G, then O, but it is not the case that if S & G', then O, where G' is any proper subset of G. ** (1) and (2) illustrate the importance of quantifier order. Compare: As either You can fool some of the people all of the time There are some people whom you can fool all the time, or At any time whatsoever, there are some people whom you can fool. That is: (Ex)(t)((Tt & Px) Fxt) vs (t)( Ex)((Tt & Px) Fxt) It may be that the appearance of a crisp distinction between (1) and (2) is deceptive. Suppose Q believed merely that there was no principled way to draw an outer bound excluding some sentences from revision when some hypothesis H was to be tested. Later Quine. In a paper published in 1975 ("On Empirically Equivalent Systems of the World" in Erkenntnis 9) Quine wrote: "Science is neither discontinuous nor monolithic. It is variously jointed, and loose in the joints in varying degrees. In the face of a recalcitrant observation we are free to choose what statements to revise and what one to hold fast, and these alternative will disrupt various stretches of scientific theory in various ways, varying in severity. Little is gained by saying that the unit is in principle the whole of science, however defensible that claim may be in a legalistic way." (314-5) Problem: Can simple or direct observation statements really be held true come what may? Quine invokes hallucinations and changing the laws of 6

7 logic. Seems desperate. But suppose that Quine, the incipient naturalist, sees our sensory systems as complex measuring instruments (which have to calibrated, working properly, and in the proper environment). Then Duhem's argument that all experimental (observational) results are "theory-laden" or in need of interpretation can be applied to our sensory systems too. This move is not so desperate. Later Quine. In a paper published in 1975 ("On Empirically Equivalent Systems of the World" in Erkenntnis 9) Quine makes the following confusing set of remarks concerning observation statements: "These statements are indeed separately susceptible to tests of observation; and at the same time they do not stand free of theory, for they share much of the vocabulary of the more remotely theoretical statements. They are what link theory to observation, affording theory its empirical content. Now the Duhem thesis still holds, in a somewhat literalistic way, even for these observation statements." (314) Question: Are there really no statements that can't be revised? Putnam s example: Not all statements are true and false. Does this represent a deep insight or the limits of our imaginations? Would it suffice if Quine showed that the class of unrevisable statements is much smaller than hitherto supposed? On p. 298 Quine does subscribe to a version of a "levels' picture of laws that is usually associated with foundationalism. We "posit" objects to induce "a manageable structure into the flux of experience." In turn, the (descriptive or phenomenological) laws ordering the behavior of objects are themselves ordered (or explained) by positing micro-objects (and their attendant laws). Underdetermination: "Total science, mathematical and natural and human, is similarly but more extremely underdetermined by experience. The edge of the system must be kept squared with experience; the rest, with all its elaborate myths or fictions [the various "posits"], has as its objective the simplicity of laws." (298) 7

8 May there not then be equivalent (equally simple, equally well-squared with experience at the edge) yet distinct total systems of science? Quine answers this question affirmatively. Later Quine again: "This holism thesis lends credence to the under-determination theses. If in the face of adverse observations we are free always to choose among various possible adequate modifications of our theory, then presumably all possible observations are insufficient to determine theory uniquely." ("On Empirically Equivalent Systems of the World" in Erkenntnis 9, p. 313) What does 'adequate' mean? What justifies its use in this argument? 8