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tor Henri Lauener's sixtieth birthday Abstract

Naturalism·holds that there is no JUsher access·to truth thaD empiricaDy testable hypotheses. Still it does not repudiate untestablo hypotheses. '!bey fill out iDtendces of 1beo1y and lead tQ furt:helo ~theses that uetestable. A hypothcisis J8 tested by dccfuc:ing. from it and a baCkground of accepted theory, some observation categorical that dOes not folfOwfrom thebackground a1oDo. 'lbis categorical, ageneraIiZed conditiODal compounded of two observation 1SCDteDces, admits in tum of a priDdtive experimental test. . ' . 1'0 o~dODsentoDces themselves,liko apecriesand bird calls, ue in hoJopbrasticUlOciadoD With ranau of noural Jntab. DoqOtadOD of determfnate objects figures neither fa thIa a.uocfation Doria deducing the eategerical from the scientific hypotheses. HeDce tho fndeter. miJIacy of Ieferaace; ~ is puzeJ.y auxiIiaIy to tho st:l1ICtlml Ofthooxy. 'Iiutb. however, is seenstiIlu transcendollt at leastiD this 8eDSO~wesay ofa suporsodcdscientifictheorynotthat it ceased to be true, but that it is found to have been false. . ....

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Names ofphilosophical positionS are a necessary eviL They are necessary because we need tQ refer to a stated position or doctrine from time to time, and it would be tireSOme to keep restating it. Theyare evil in tbat they come to be conceived as deSignating schools ofthoupt, objects of loyalty from within and obj~ of obloquy from without, and hence obstacles, within and without, to the pursuit of truth. In identifying the philosophical position that I call naturalism, then, I shall just be· describing my oWli p(>sition, without prejudice to possibly divergent uses ofthe term.ID Theories and Thlngs I wrote that ~turalism is "therecog"; .• nition that it is ~ science itself, and not in some prior philosophy, that reality is to be identified and described"; again that it is "abandonment of the goal ofa first philosophyprior to natural science" (pp. 21, 67). Th~ ~e­ teriz8tions convey thO. right moQd, but they would fare Poorly in a·debate. How much qualifies as "science itself" and not "some prior philosophy"? • Harvard University, USA

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It1 science itself I certainly want to indude the farthest flights of physics aDd cosmolo81l as well as experimental psychology, history, and the ~oeial .sciences. Also ~tic:s, insofar at least as it is applied, for it is indispens. able to natural sclence. What thea amIexcluding as "some priorphilosOphy," and why? Descartes' dualism between miDd and body is called metap~ysics, but it could as weD be reckoned as science, however false. He even had.a causal theory of the Interacdoft of mind and body through the pineal gland. If I saw indirect explanatory benefit in positing sensibilia, possibilia,spirits, a Creator, I wouldjoyfully accord theJn scientific status too, on a par with such avowedly scientific posits as quarks and black holes. What then have I banned tinder the name of prior philosophy? . Demarcation is notmypurpose. My pointin the characterizations of naturalism that I quoted is just that the mostwe can reaso:i1ablyseek in support of .an inventory and description of reality is testability of its observable couse. quences in the time-honored hypothetico-deductive way - wher.eof m?re anon. Naturalism need not cast asperSions on irrespoDSlole metaph)'Slcs,. ·however deserved, much less on soft sciences or 011 the speculative reaches of the hard ones, except molar as a firmer basis is claimed for them than the ex" perimental method itself. ~ naturalistic renunciation shows itself most clearly and significantly is in naturalistic epistemology. VarioUs epistemologists, from Descartes to Carnap, had'sought a foundation for ~tu:ral scien~ in mental enti,ties, the flux of raw sense data. It was as if we JDlght first fashion a s~lf-suffiC1ent and infallible lore ofsense data, innocent of referenCe to physical things, and then build out theory of the external world somehow on that finished foundation. The naturalisticepistemologist dismisses this dream ofpriorsense-datum language, arguing that the positing of physical things is itself our indispensable tool for organi?:ing and remembering what is otheJ;Wise, in James' words, a "blooming, buzzing confusion." To account for knowledge of an external thing or event, accordingly, the naturalistic epistemologist looks rather to the external thing or event itself and the causal chain of stimulation from it to one's brain. In a paradigm case, light rays are reflected from the object to one's retina, activating a.patch of nerve endin~, each of which initiates a neural impulse to one or another center of the bram. Through intricate processes within the brain, finally, and abetted by imitation o.f other peopleorbyinstruction, a cbildcomesin tim~ to ~ or assentto s?me rudimentary sentence at the end ofsuch a causal cbain. I call It an observation sentence. Examples are "It's cold"t "It's raining", "(I'hat's) milk", "(1bat'~ a) d~g". . Customarily the experlniental psychologist chooses one or another obj~ or event, from somewhere along such a causal chain, to represent the chain,

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.and this he caDs the stimulus. Usually it is an event of his own devising. In one -~ent it will be a flash or a buzzin the subject's vicinity, and in another it will bean Ice cube or a shock at the subject's surface. For our more general purposes, not linked to any particular experimen~ an.economical ~gy in defiDing the stimuIusis to inteIcept the causal chains jUst at the subject's surface. Nothing Is lost, for it Is omy from that pOint Inward that the chains contribute to the subject's knowledge of the external world. .' Indeed,evenwhat.reaches the. subject's surface is relevant only if it triggers . neural receptOrs.'So we might for our purposes simply identify the subject'~ $timulus, over a given brief moment, with the temporally .orderedset of senSory receptors triggered in that moment . '. . "'.;. Still further economy might be sought by mtercepting the causal chains rather at a ~per level- somewhere within the brain; for even the surface reCeptors that are triggered on any given occasion are largely without relevant effect on the subject's behavior. However, our knowledge of these deeper levels Is still too sketchy. Moreover, as ~ Jncreaslng1y penetrates these . depths, we become aware of complexity and heterogeneity radicaUy a! variance withthe neatsimplicityatthe surface. Each receptor, after all, admits of just two clean-cut states: triggered or no.t .' .Moreover, the behaviorally inelevant triggerings in a global ~ul~ can be defined out anyway, in due course, by appeal to perceptual siJDilarity of stimuli. The receptors whose firing is sa/ientin a given stimulus are the ones that ·it shares with all perceptually similar stimuli. Perceptual ~ty itself 'can be measured, for a given individual,.by reinforcement andextincdon of responses. "":-ul So it seems bestfor present purposes to construe the sub·---' ~~s .n....... us on a giVet1 occasion simply as his global ne~ intake on that ~ut I shaD refer to it only as neural intake, not stimulus, for other notions ofstimulus are wanted in other studies, particularly where diffe~l1t subjects are to get the . same stimulus. Neural intake is private, for subjects do not share receptors. Perceptual similarity, then, is a relation between a subject's neural intakes. Though testable, it is a private affair; the intakes are his, and arepe~ptually more or less similar for him. Perceptualsimilarity is the basis ofallleaming, all habit formation, all expectation by inductionfrom past experience; forwe are innately disposed to expect simDar events to have sequels that are similar to each other. The association of observation sen~ with neural intakes is manymany. Any one of a iange of perceptually fairly similar intakes may prompt tho subject's assent to anyone of a range of semantically kindred sentences. But in contrast to the privacy of neural intakes, and the privacy of theJr ~

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~ptUal sUniIarity, observationseiltelices and their sentaDti<:s are a public mat· ter, since, the child has to learn these from her elders. Her learning depends indeed both on the public currency ofthe observation sentences and on

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a preestabDshed harmony of people's priYate scales·of perceptual similarity. The harmony is formal, in this sense: ifa Witness finds the first of three scenes less similar to the second than to the third; another witness is apt to do likewise. This approximate harmony is preestabDshed in a shared gene pooL Different people's feelings still might not match, whatever that might mean. This much is a naturalistic analogue or counterpart of the traditional epi.stemologist's phenomenalistic foundation in sense data. However, it pretends 'to plausibility in psychology, in genetics, and even in prehistory. Observation sentences haVe their antecedents in birdcalls and in the signal cries ofthe apes. BuDding on this naturalistic founda"tion, then, in parallel to the old epistemologist's proposed construction ofscience on a foun,dation ofsense data, the natUtaJist would venture a psychologically and historically plausible sketch of the indiVidual's acquisition of science and perhaps the evolution of science down the ages, with an eye primarily to 'the logic of evidence. I will spare you most ofthat, for I have gone into it in Word and Objectand better in The Roots of Reference, Pursuit of Truth, and elsewhere. There are just a couple of aspects that I want to remind you of. . One is reification, or the positing of objects. Observation sentences commonly contain words that refer to objects when used in mature discourse, but the infant first acquires such a sentence only as a seaIIl1ess whole, conditioned - like the signal cry of the ape - to an appropriate range of global neural intakes. But there is a harbinger of reification already in our innate propensity, and that of other animals, to confer salience on those components of a neural intake that t:ta:nsmit cprporeal patches of the visual field. It is what Donald Campbell caDs our innate reification of bodies, but I construe reification rather in degrees., Special ways of compounding observation senten~ mark farther stepsm the reification ofbodies~ and the job is complete only when the speaker bas mastered past and future tense and knows about 1;Jie UDSeQD but . continuous tI:ans1ation of an identical body through space between ob~a­ tions. It is onlythen that she makes sense ofa body's being the same bodyfrom one observation to aIlother despite intervening changes in appearance. At that point the reification of bodies is full fledged. Reification of less conspicuous objects, notably abstract ones such as numbers and classes, takes ,farther explaiiJing, and admits of it. A crucial step there, as I see it, is mastery of relative ~uses and pronouns. '.. '':'.... This butgeoning language'of science is a direct extension of the faltering ~ge of observation. Segments of ob$C1'V8tion.senten~ carry over and

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'become.- so~o of them ~ terms for objects. Convorso!y, SODteDcosleamed synthesis from a sophisticated vocabulary can come to qualify as observationsentences as welL For, what I take as definitive ofobservation sentenceS is just tbis pair of conditions: first, the speaker must be disposed to assent to the sentence or dissent from it outright on making the appropriate pbservation, irrespective of his interrupted line of thought if any, and second, the verdict must Command the agreement of any witnesses from the appropriate language community~ This second requirement,intersubJectivity, is needed in order that the child be able,to learn observation,sentences from his elders; and those sentences, some of them, arc his indispeIisable en,; terillg wedge in acqUiring cogQitive language. Intersubjectivity ofobservation sentences is likewiie essential at the other end, to assure objectivityof science. The sharing of vocabulary by observation sentences aild sentences of science was necessary not only for the emergence ofsci~tific language; it is necessary also as a Channel for the empirical testing of scientific hypotheses. The primordial hypotheses are what I call observation c:ategoricals, compounded ofpairSofobservationsentences: thus "Whenitsnows, it's cold". To check such a hypothesis experimentally, we contrive to put ourselves in a situation where the first component, "Ifs snowing", is observably fulfilled, and tb;en we check 'for fulfillment of the second.component.· If it i$ fulfilled, the categorical remains standing until further notice. If it is not fulfilled, the categorical is refuted once for all. " '., : . ,...: I see this as the key to the empirical testing also of more sophisticated hypotheses. We conjoin the hypothesis in,question to a set ofalready previously accepted statements, sufficient together to imply some observation categorical that was not implied by the previous set alone. Then we check the observation categorical. The appeal to logical implication here presents no problem. Tho basic laws of logic ,are interoaJized in learning the use of the logical particles•.For instance, the childlearD$ by observation and parental correction that it is misuse ofthe conjunction "and" to affirm an "aild" colDpound aIld then deny one of the components. The,childhas thus itemalized onesimplelogicalimplieation, namely that "and" compound implies its components, on pain of simply getting a wordwrong. CorreSpondinglyfor other basic implications, up to and including the laws of quantifiers' and identity. Insofar I ~ with Lauener in recogniZing 'analyticity. .Scientists of course. do not trace all these,Jinks of implication from hypo.!J1~. to observ8tio~ categorical. It would mean filling in an the logically reqUisite suppoiting statements, most of which are so familiar to him 80 trivial as to go without saying. In practice, moreover, many tacit premisses often ~oDly later by ~tical

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256 • express ~eIe sta1istical trends or probabilities, which he will take in stride unless Unexpected results prompt him to reconsider. , '' " StiU the deduction and checking ofobservation categoricaJs is the essence, ,surely, of the experimental method, the hypothetico-deduetive method, 'the method, in Popper's 'Words, of conjedU!e and refutation. It brings out that prediction of observable events is the ultimate test of scientific theory. I sPeak of teSt, not p~ The purpose ofscience is to be sought rather in mteDectual outIOIity and toclmoJogy. In our prehistoric begfnnjnglJ, hoW" eve-r, the purposo 01 tho first gJimmerings of scientific theory ~ prcsuma~ly prediction, insofar as purpose can be despiritualized into natural selection and survivaJ value. 'Ibis takes us back to our innate sense or standard of perceptual similarity, and the innate expectation that similars will have mutually similar sequels. In short, primitive induction. Prediction is'verbaIized expectation. Conditional expectation, when COl'rect, has survival value. Natural selection has accordinglyfavored innate standatds of perceptUal similarity that have harmonized with trends in our environment Natural science, finally, is conditional expectation hypertrophied. I said thatprediction is not the main purpose ofscience,but onlythe test. It ,is a negativetest'atthat, a test byrefutation. As a further disavowal let me add, ,contrary to positivism, that a sentence does not even need to be testable in order to qualify as a respectable sentence ofscience. A sentence is testable, in my liberal or holistic sense, if adding it to previously accepted sentences clin" chesan observation categorical that was notimplied bythose'previoussentences alone; but much good science is untestable even in this liberal sense. We believe many things because they fit in smoothly by analogy, or they symme, triZe and Simplify the overall design. Sureiy much history and social science is of this sort, and some hard science. Moreover, such acceptations are not idle fancy; their proliferation generates, every here and there, a hypothesis that can indeed be tested. Surely this is the majorsoun:eoftestablehypotheses and the growth of science. The naturalization of epistemology, as I have been sketching it, is both a limitation and a h'beration. The old quest for a foundation for natural science, firmer than science itself, is abandoned: that much is the limitation. The liberation is fiee access to the resources ofnaturaI science, without fear of circularity. The natu,raUstic epistemologist settles for what he can learn about ,the strategy, logic, and mechanics by which our elaborate theory of the physical world is in ,fact projected, or mightbe, or should be, from justthat amorPhous ' neural intake. Is this'sort of tbin& still philosophy? Naturalism briDp a salutary blUI'I'iQg of' such boundaries. NaturaHstic philosophy is continuous with Il8tural

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sci~ce. It undertakes to cIarify, organize, and simpBfy the broadest'and most

basic:'Concepts, and to analyze scientific method and evidence within the framework of science itself. The boundary between naturalistic philosophy and the rest of science is just a vague matter of degree. ,'.' ,"' :' Naturalism is naturally associated with physicalism, or materialism. I do not equate them, as witness my earlier remark on Cartesian dualism. I do embracephysicali$m as a scientific poBitioD, but I could be dissuaded of it OD fu~ turelJcJendfic grounds without beJng dissuaded ofnaturilJam. Quantum mechanics today, indeed, in its neoclassical or Copenhagen interpretation, has a distinctly mentaIistic ring. ' My n~turaIism has evidently been boiling down to the claim that in our pW'Suit of truth about the world we cannot do better than our traditional scientific procedure, thehypothetico-dedUctive method.,A rebuttal suggests itselfhere: surelymathematicians. The obvious defense againstthat rebuttal is to say that IIlatb,ematiCal truths are not about ,the world. But this is not a defense of my choosing. In my view applied mathematics is about the world. Thus consider again a case where we are testing a scientific hypothesis by conjoining it to some aIreadyaccepted statements and deducing an observation'categorical. Likelyas not, some ofthose already accepted statements are purely mathematicaL This is how pure mathematics gets applied. Whatever empirical content those already accepted statements cin claim, then, from being needed ~ implying the observation categorical, is,imbibed in particular by the mathematlcaI ones. Thus itis that I am iodined toblurtheboundarybetweenmathematics and natural science, no less than the boundary between philosophy and natural science. If it is pro~ that proved mathematical truths are not subject to subsequent refutation, my answer is that we safeguard them by choOsing to revoke non-mathematical statements instead, in cases where a set of sta~ ments has been found conjointly to imply a false observation categoric8L ReaSons can be adduced for doing so; but enough. That l~ves open the vast prolifer8tions of mathematics that there is no thought or proSPect ofapplying. I see these domains as integral ~ our ove.raU theory of reality onlyon sufferance: they are expressed in the samesyntaxand lexicon as applicable mathematics, and to exclude them as meaningless by ad hocgerrymandering ofour syntax would be thanldess at best. So it is left to us to try to assess these sentences also as true orfalse, awe care to. Many are settled by the same laws that settIe applicable mathematics. For the rest, I would settIe them as far as practicable by considerations ofeconomy, on a par'with the decisioDS wem. in naturallOioncowhon trying to framoC!mpirJcalhypotheses worthy of ~taltesting. I

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TraditiolJ81 epistemology was in part nonnative in intent. Naturalistic epistemology, in contrast, is viewed by Henri Lauener and others as purely desCriptive. I disagree. Just as traditional epistemology on its speculative side gets naturalized into science, or next of kin, so on its nonnative side it gets naturaliZed into technology, the teclmology of scientizing. What might be offered first of an a norm of iJatUtalized epistemology is pte'dietioll ofobservation as a test of a hypothesis. I think oftbisas more than a nonn: as the name ofthe game. Science cannot an be tested, and the softer the science the spatser the tests; but when it is tested, the test is prediction of observation. Moteo'\7er, naturalism has no special claims on the principle, which is rather the crux of empiricism. . What are more distinctively naturaliStic and technological are nOrmJbased on scientiilcfindings. Thus science has pretty well established - subject to fu~ disestablishment, as always - that our information about distant events and other people reaches us only through impact of mys and particles on our sensory receptors. A normative corollary is that we should be wary ofastrologers,palmists, and other soothsayers. Think twice about E.S.P; . For a richer array of norms, vague in various degrees, we may look to the heuristics of hypothesis: how to think up a hypothesis worth testing. This is WbereCObSidetations of conservatism and simplicity come in, and, at a more .teclmica11evel, probability theory and statistics. In pmctice tbosetechnica1 matters·spillover also, as I remarked, to complicate the hypothetico-deductive method itself. I said at the beginningofthis paper that according to naturalism it is within science itself and not soDie prior philosophy that reality is to bo idontified. Farther along in a more narrowly scientific spirit, I speculated on how we round out our recognition ofobjects as objects, bit by bit, with our acquisition of1angU8ge and science. These matters can now for some more broadly pbi1~ osophical reflections. . . Let:us recall, to begin with, that the association of observation sentences with neural intake is holophrastic. What objects the component words may designate in other contexts is irrelevant to the association. This is obviouslyso if tho observation sentence is to be acquired as a first step in language leam.. ing; but the association is equally direct ~d holophrastic in its operation even if the sentence was acquired through synthesis ofits words, and gained its immediacy only through subsequent familiarization. . ~oreover, the specifics of designation and denotation are not only indif· fetent to ·the association ofobservation sentencei to neural intake; thoyare in.. . . dlttetellt alSo to the ImpHcatlOl1 of obseMlioll categorlca1s by 8cien~c ~~~. ·ory. It is logical implication; logic, unlike set theory and the rest ofifult.lj~

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IDatics, responds to no traits of objects beyond sameness and difference. So wc·must conclude that objects ofany sort :figure only as neutral nodes in the structure of scientific theory, so far as empiiica1 evidence is concerned. We can arbitrarily change the values ofour variables, the designata ofour names, and the denotata of our predicates without disturbing the evidence, so long anyWay as the new objects are explicitly correlated one. to one with the old. Such is the indeterminacy of refere,oce, as I have come to can it Ai first it is perhaps alarming. We are left with no basis, it would seem, for judging whether we are talking about famjJjar things or some arbitrary proxies. The shock subsides, however, when we reflect on a homely example ot two. Thus tbiDk ofa body in the scientific framework ofspace and time. Insofar as you specify the precise sinuous filament of four-dimensional space~ time thattbe body takes up in the course of its career, you have fixed the object . uniquely•.We could go farther and identify the object, a chipmunk perhaps, with its portion ofspace-tiJne, thus sayingthatit is $y at its early end and bigger at its late end. The move is artificial, but actually it confers abit of economy, if we are going to have the space-time anyway. Subjective connotations ofbrownness, softness~ swift and erratic movement, and the rest simply carry over. Surely all matters of evidence·remajn undisturbed. We are even·prepared to say that it was whut a·body was all along, an appropriately filled-in .portion ofspace-ime as over against empty ones. Next we might identify space-time regions in tum with the sets of quadru· pIes ofnumbers that determine them in some arbitrarily adopted frame of ea.ordinates. We can transfer sensOry connotations now to this abstractmatbomatical object, and still there is no Violence to scientific eVidence. To speak in· tuitively, nothing really happened. . Thus we can come to terms somewhat with the indeterminacyofreference, as applied to bodies and other seDSlble substances, by just letting the sensory connQtations of the obserVation sentences cariy over from the old objects to their proxies. In the case ofabstract objects such as numbers, devoid ofsensoryconnotations, the indeterminacy ofreference is already familiar. It is seen in Frege's so-called Caesar problem: tho DUmborfive may be Julius Caesar. We happily use nU%Dbers without caring whether they be taken .according to .the FregeRussell constructions·orAckermann's or von Neumann's. The point was dramatized long ago by~ F.P. Ramsey with his expedient of Ramsey sentences, as they have como to be called. Instoad.Qf Invoking tho.abstract objects spociB~, wbon QOi1ajg. of Ulelr propertiea are neoded in IIllfgument, the Ramsey sen~c:e Just says that there objects with the propenies, and then invokes the;~bjeas· by variables without further identification. This expedient oDly

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works for abstract objects, however, used as auxiliaries here and there without regard to whether they remain the.same objects from ODe context to another•. ~e indetermiDacy of reference can be seen again in its fuJi generality, as DaVidson once remarked, by an cmnnination ofThrski's cJ8ssical truth defiDition.1f a sentence comes out true under that definition, it continues to do so when objects are reassigiledto its predicates in any one-to-one way. . These reflections on ontology a salutary remin~er that the ultimate data ofscience are limited to our neural intake, and that the verynotion ofobject, con~te or abstract, is ofour own making, along with the rest of natural science and mathematics. It is our overwhelmingly ingenious apparatus for systematizing, predictin& and partially controlling our intake, and we may take pride. , This conventionalist yiew ofontology appeals, I expeCt, to Henri Lauener. He in his pragIDatism even settles for a plurality ofscientific specialties, each . with its working ontology, and no dreaID of an overarcbing, unifying fact of the matter. , Naturalism itself is noncommittal on. this question of unity of science. NatutaJism just sees it as a question.within science. itself, 'albeit a question more remote from observational checkpoints than the most speculative questions of the hard and soft sciences ordinarily so called. . Naturalism can still.respeet the drive" on the part ofsome of us, for a uni-tied, an-piupose ontology. The drive is typical ofthe scientific temper, and of apiece with the drive for ~plicity that shapes scientifichypotheSes generally. Physicalism is its !amniar manifestation, and physicalism is bOUnd to have had . ~portant side effects in the framing of morc .pecial hypOtheses in various branches ofscience; for physicalism puts aptemiUlil on hypotheses favorable to closer integration with physics itself. We have here a conspicuous case of what I touched on earlier: scientific hypotheses which, though not themselves testable, help to elicit others that ~ In any event, we are now seeing ontology as more utterly a human option .than we used' to. We are drawn to Lauener's pragmatism. Must we then conclude that true reali~ is beyond our ken? No, that would be to forsake naturalism. Rather, the notion of reality is itself part of the apparatus; and sticks, stones, atoms, quarks, numbers, and classes all are utterly real denizens of an . ultimate real world, except insofar as our present science may prove false on further testing. . , . What then is natUralism's line on truth and talsity themselves? The tnith ptedicate raises no problem in its normal daily use as an instrument of what J have called semantic ascent. 'IBrski's disquotational account accommodates it, so long as what are called true are sentences in our own language; an4 we

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thC11 ~d the predicate to sentences of other languages that we accept as of trutbs of our own. However, paradoxes arise when the truth predicate is applied to sentences. that contain that very predicate or related ones; so w~ are caI1ed upon to recognize rather a hierarchy oftruth predicates, each of which behaves properly only in application to sentences that do not contain thatpredicateitselforhigher ones. It is aheirarchy of better and better truth predicates but no best. In practice, eXcept in contexte such as these phiJosphica1 ones, occasions seldom arise for venturing above the first rung of the ladder. 'liuth olfthe heirarchy,absol~te truth, would indeed be transceJident; bringing it down into scientific theory of the world engenders paradOx. So naturalism has no plac:e for that. .Still,' our concept of truth strains at its naturalistic moorings in another way. We naturalists say that Science is the highest path to truth, b~t stiD we do not say that everythirig on which scientists agree is true. 'Nor do we say that . sometbip.g that was true became false when scientists changed their minds. What we say is that they and we thought it was true, but it wasn't. We have scientists pursuing truth, not decreeing it,1i:uth thus st8nds forth as an idealof pure reason, in Kanfs apt phrase, and transcendentindeed. On this score I am ag~ with Lauener. . C.S. Peirce tried to naturalize truth by identifiying it with'the limit that scientific progress approach~. This depends on optiJnistic assumptions, but if w,e reconstrue it as ~ metaphor it does epitomize the scientists' persistent give and take of conjecture and refutation. 1i:uth as goal remains the established usage of the term, and I acquiesce in it as just a vivid metaphor for our continued adjustment of our world picture to our neural intikc. Metaphor is perhaps a handy cate$ory in which to accommodate transcendental concepts, from a naturalist point ofview. ' . ~tions

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Yol. 49, N° 2-4 (199,)