Davidson's objections to Quine's empiricism. Lars Bergström Stockholm University There are many similarities between Donald Davidson's philosophy and W. V. Quine's, but there are also differences. One difference has to do with Quine's empiricism. As everyone knows, Quine has argued that the notorious "two dogmas of empiricism" should be abandoned, but he himself is definitely still an empiricist.1 Davidson, on the other hand, has drawn attention to a "third dogma of empiricism", which he attributes to Quine among others. Davidson has argued that this third dogma should also be given up, and he suggests that when it is gone there is nothing left to call empiricism.2 In this paper I shall describe this apparent disagreement between Davidson and Quine in more detail, and I shall argue that Quine's empiricism is not really undermined by Davidson's arguments.3 1. The third dogma of empiricism. What Davidson refers to as the third dogma of empiricism is a certain "dualism of scheme and content", which occurs in the work of many philosophers. Davidson claims that such a dualism is a presupposition of all forms of conceptual relativism. Roughly speaking, the third dogma is that conceptual schemes-which can be identified with languages or with sets of intertranslatable languages4-are used to organize or give structure to something which constitutes the raw material, as it were, for our beliefs and theories. For an empiricist, this raw material is empirical content. According to Davidson, empirical content "is in turn explained by reference to the facts, the world, experience, sensation, the totality of sensory stimuli, or something similar".5 This dualism of conceptual scheme and empirical content is the target of Davidson's criticism. He writes: I want to urge that this [...] dualism of scheme and content, of organizing system and something waiting to be organized, cannot be made intelligible and defensible. It is itself a dogma of empiricism, the third dogma. The third, and perhaps the last, for if we give it up it is not clear that there is anything distinctive left to call empiricism.6 1. See Quine, "Two Dogmas of Empiricism." 2. Davidson, "On the Very Idea of a Conceptual Scheme," 11. 3. I am grateful to Donald Davidson, Roger Gibson, Sören Häggqvist, Peter Pagin, W.V. Quine and Folke Tersman for helpful comments on earlier versions of this paper. 4. "On the Very Idea of a Conceptual Scheme," 7. 5. Ibid., 11. 6. Ibid. 2 Davidson claims that Quine accepts this dualism of scheme and content, the third dogma of empiricism. Personally, I am not so sure, but this is mainly because I am not sure what the dogma says. If it only says that there are these two elements, scheme and content, then it seems clear that Quine accepts it. Quine's empiricism can be summarized in the two theses that "whatever evidence there is for science is sensory evidence", and that "all inculcation of meanings of words must rest ultimately on sensory evidence".7 Moreover, he identifies sensory evidence with the triggering of sensory receptors.8 It seems clear that Quine admits the existence of both conceptual scheme (language, theory) and empirical content (sensory evidence, i.e. the triggering of sensory receptors). But presumably the third dogma also says that schemes "organize" or "fit" the relevant content. Davidson writes: The images and metaphors fall into two main groups: conceptual schemes (languages) either organize something, or they fit it [...] The first group contains also systematize, divide up (the stream of experience); further examples of the second group are predict, account for, face (the tribunal of experience).9 The question, then, is what is meant by this. Quine believes that there is an interesting relation between language (or theory) and sensory evidence. In fact, the main purpose of his naturalized epistemology is to study this very relation. But would he claim that language "organizes" or "fits" sensory evidence (in the sense that Davidson finds objectionable)-or that it ought to do so? That is hard to say. 2. Quine's view of the third dogma. Quine has replied to Davidson's paper.10 In this reply, he makes a distinction between two different interpretations of the third dogma. On one of these interpretations, he accepts the dogma; on the other, he rejects it. He writes: If empiricism is construed as a theory of truth, then what Davidson imputes to it as a third dogma is rightly imputed and rightly renounced. [...] As a theory of evidence, however, empiricism remains with us, minus indeed the two old dogmas. The third purported dogma, understood now in relation not to truth but to warranted belief, remains intact. It has both a descriptive and a normative aspect, and in neither do I think of it as a dogma. It is what makes scientific method partly empirical rather than solely a quest for internal coherence.11 7. Quine, "Ontological Relativity," 75 (italics have been removed here). 8. See Pursuit of Truth, 2. 9. "On the Very Idea of a Conceptual Scheme," 14. 10. "On the Very Idea of a Third Dogma," 38-42. 11. Ibid., 39. 3 So Quine accepts a certain "dualism of scheme and content". As an empiricist, he believes that our beliefs about the world are, and should be, based upon experience-where, for him, "experience" is identified with the triggering of sensory receptors (surface irritations). At the same time, he also accepts Davidson's argument against a different kind of dualism, namely an empiricist theory of truth. According to such a theory a sentence is true, roughly speaking, if it is entailed by a theory which fits the totality of possible sensory evidence.12 Quine takes Davidson's argument against the third dogma to be directed against an empiricist theory of truth.13 This might leave the reader with the impression that there is no disagreement between Quine and Davidson on these matters after all. But I believe such an impression would be mistaken. Let me explain. It seems that empiricism may take one or more of at least three different forms. These may be referred to as empiricist theories of truth, empiricist theories of evidence, and empiricist theories of meaning. I myself have argued elsewhere that there is some support in Quine's writings for an empiricist theory of truth.14 Quine has rejected this suggestion. However, it seems clear that he is an empiricist with respect to evidence and meaning.15 Davidson, on the other hand, appears to reject all three kinds of empiricist theories. I believe he would say that they are all unacceptable, since they all contain the third dogma of empiricism. So there is still disagreement between them. 3. Proximal and distal theories of meaning. Let us now consider their disagreement concerning meaning. (I will return to the question of evidence in section 9 below.) In his paper "Meaning, Truth, and Evidence", presented at the St. Louis conference on Quine's philosophy in 1988, Davidson makes a distinction between proximal and distal theories of meaning and evidence. He writes: Our knowledge of the world depends directly or indirectly on elaborate and perilous causal sequences that originate with events like a rabbit scurrying by, or a spasm in the stomach, progress through the nervous system, and terminate in beliefs. Where, in the chain of causes and effects, do we come across the items that give our beliefs 12. Compare Davidson's "On the Very Idea of a Conceptual Scheme," 15; and Bergström, "Quine, Empiricism, and Truth." 13. See "On the Very Idea of a Third Dogma", where Quine writes: "Against the purported dogma he argues that 'the notion of fitting the totality of experience, like the notion of fitting the facts, or being true to the facts, adds nothing intelligible to the simple concept of being true ...'," 39. 14. Bergström, "Quine's Truth" and "Quine, Empiricism, and Truth". 15. Compare the two theses that "whatever evidence there is for science is sensory evidence", and that "all inculcation of meanings of words must rest ultimately on sensory evidence" quoted in section 1 above. 4 their particular contents and our words their meanings? [...] A clever compromise brilliantly advocated by Quine is to tie meaning and content to the firings of sensory nerves.16 The firings of sensory nerves-the triggering of sensory receptors-is called the proximal stimulus (in the causal sequence), and Quine's theory of meaning is therefore a proximal theory. Davidson wants Quine to abandon this theory, and he points out that this "would mean relinquishing what remains of empiricism after the first two dogmas have been surrendered".17 However, Davidson also claims that there is another account of meaning in Quine's work, which ties meaning and evidence to more distal stimuli in the causal sequences, namely to "the very events and objects that the sentences are naturally and correctly interpreted as being about".18 The distal stimuli in Davidson's example are the scurrying of the rabbit and the spasm in the stomach. The resultant theory of meaning, which is the one that Davidson accepts, is a distal theory.19 It is not quite clear to me whether the proximal and distal theories are exclusively concerned with the meaning of observation sentences. For simplicity, we may assume that they are. Maybe they can later be extended to cover more theoretical sentences as well. There is some indication that Davidson takes a distal stimulus to be publicly or intersubjectively observable.20 On the other hand, a spasm in my stomach is hardly publicly observable, so maybe the distal theory is also concerned with theoretical sentences. Davidson refers to causal sequences which "originate" in distal stimuli, such as a rabbit scurrying by. Surely, however, the causal sequences go much further back. So maybe Davidson's point is that we need not go any further than the distal stimulus, where this is defined as what the sentence is about. If so, however, we may not have to bother about causal sequences at all. If we already know what a given sentence is about, why do we want to consider the causal sequence which leads up to the utterance of it? In general, it is not clear to me why there must be any particular item in the actual causal sequence leading up to a belief which "gives" the belief its particular content and the words in the corresponding sentence their meanings. (Another thing is, of course, that interpretation may often involve or depend upon assumptions about causality.) A more plausible alternative is that the distal stimulus is defined, not as what the corresponding sentence or belief is about, but as the closest event in the causal chain which is publicly observable and also salient in the situation. In one place, Davidson says that "[w]hat narrows down the choice of the relevant cause is what is salient for speakers and 16. "Meaning, Truth, and Evidence," 68. The "compromise" referred to here is between external things, on the one hand, and internal "raw material of thoughts" such as sense data, on the other. 17. Ibid. 18. Ibid., 72. 19. Ibid., 73 20. See ibid., 72-3. 5 their interpreters."21 On the distal theory, this salient cause is what determines the meaning of an observation sentence. 4. Quine's proximal theory of meaning. What determines the meaning of an observation sentence according to Quine? How, more precisely, does the triggering of sensory receptors "give our beliefs their particular contents and our words their meanings" (as Davidson puts it)? For Quine, "the central problem of the theory of meaning" is to define meaning in nonintensional terms.22 The way to start is to define sameness of meaning or (cognitive) synonymy. If this can be defined, we may simply say that the meaning of the sentence S is the set of all sentences, including S itself, which have the same meaning as S.23 So the problem is to define sameness of meaning. However, one and the same sentence may have different meanings for different persons and for the same person at different times. Therefore, sameness of meaning cannot be taken as a simple two-place relation. On the other hand, it is usually assumed that one sentence may have the same meaning for a certain person as another sentence (or the same sentence) has for some other person. This is perhaps a presupposition of translation and communication. Consequently, we must also distinguish between intrasubjective and intersubjective sameness of meaning.24 Quine can be said to be both a verificationist and an empiricist about meaning, since he takes the meaning of a sentence to be at least roughly the same as the empirical evidence on which the sentence may be assented to or dissented from. In one place, he writes the following: The statement of verificationism [...] is that "evidence for the truth of a sentence is identical with the meaning of the sentence"; and I submit that if sentences in general had meanings, their meanings would be just that. It is only holism [...] that tells us that in general they do not have them.25 In general, classical verificationists hold that the meaning of a sentence can be identified with the observations which would confirm or disconfirm the sentence.26 For Quine, the "observations" which would confirm or disconfirm an observation sentence are global sensory stimulations, which consist in the triggering of sensory receptors. Consequently, he introduces the notion of stimulus meaning. The stimulus meaning of an observation sentence for a person is the range of stimulations (triggered receptors) associated with it for that 21. "Meaning, Truth, and Evidence," 77. 22. See his review of Truth and Meaning, 226. 23. See e.g. From Stimulus to Science. 76. 24. This is also pointed out by Davidson in "Meaning, Truth, and Evidence," 73. 25. "Reply to Roger F. Gibson, Jr., " 155. 26. See e.g. J. Dancy and E. Sosa, A Companion to Epistemology, 263. 6 person, affirmatively or negatively.27 Consequently, we may say that two observation sentences have the same meaning for a person at a time if and only if they have the same stimulus meaning for the person at the time. Intrasubjective synonymy of observation sentences over time can be handled in the same way. So far, so good. However, it is hard to see how intersubjective sameness of meaning could be defined in terms of stimulus meaning.28 The reason is that stimulus meanings are private; a stimulus meaning in Quine's sense is an ordered pair of sets of sensory receptors belonging to a given person. Therefore, stimulus meanings cannot be shared. But distal stimuli can be shared. Presumably, this is at least one of the reasons why Davidson prefers the distal theory of meaning. (This last point may be questioned on the ground that Davidson, in his argument against the proximal theory, seems to take it for granted that stimulus meanings can be shared. He imagines a case where two persons have the same patterns of stimulation, but where these are caused by different distal stimuli, and he says that this supposition "is not absurd".29 He also says that, "[o]n the proximal theory ... sentences have the same meaning if they have the same stimulus meaning".30 But I do not think that he himself would defend the view that a sentence may have the same stimulus meaning for different persons. Surely, no one would defend this view.) On the distal theory-if I understand it correctly-we may say that an observation sentence used by one person has the same meaning as some (possibly different) observation sentence used by another person if and only if "identical events, objects or situations cause or would cause assent and dissent".31 For example, in radical translation, my sentence "That's a rabbit" and the native's sentence "Gavagai" have the same meaning if our particular acts of assent to and dissent from them, are caused or would be caused by the same distal stimulus. However, it seems that the proximal theory might also be able to handle interpersonal synonymy. In the case of radical translation, we may think of the field linguist's hypothesis that "Gavagai" in the jungle language means the same as "That's a rabbit" in the linguist's own language somewhat as follows: If I (the linguist) were to learn the Jungle language of my informant-in the sense that I acquired the capacity to converse with him fluently and predict his actions on the basis of his utterances, and so on-then "Gavagai" and "That's a rabbit" would have the same stimulus meaning for me.32 Of course, in order to support a 27. See e.g. Pursuit of Truth, 3; and Word and Object, 32-3. 28. Quine himself says that stimulus meaning "is no part of the intersubjective business of semantics"; see "In Praise of Observation Sentences," 114n. 29. "Meaning, Truth, and Evidence", 74. 30. Ibid., 73. 31. Ibid. 32. Quine exploits the possibility of bilingual speakers to handle radical translation in From Stimulus to Science, 78. 7 hypothesis like that, the linguist might still have to use arguments which refer to distal stimuli, but this should not be inconsistent with a proximal theory of meaning. What about intersubjective synonymy in ordinary dialogue (in English, for instance)? Quine says that this is no problem for observation sentences, since "concurrence of witnesses is already a defining condition of observationality".33 But it is not obvious how this solution can be combined with a proximal theory. On such a theory one might wish to say that observation sentences have different meanings for different speakers, even though there is perhaps complete concurrence of witnesses, on each occasion. But that would be very strange. Surely, if you and I use the sentence "It's raining", say, in exactly the same way on all occasions, it may be assumed that we use it with the same meaning. Can a proximal theory give this result? I think it can. A plausible proximal theory should not identify meaning with stimulus meaning. Rather, it should say that the stimulus meaning an observation sentence has for a person determines the meaning the sentence has for the person. The meaning itself can be identified with the person's disposition to assent to, and dissent from, the sentence on various occasions. If this sounds odd, we might say instead that the meaning of a sentence (for a person) is its disposition to be assented to or dissented from (by the person) on various occasions. In any case, if two people have the same disposition to assent and dissent to the sentence on all occasions, the sentence has the same meaning for them. My suggestion may also be put as follows. Meaning is use. So, if two persons are disposed to use an observation sentence in exactly the same way, it has the same meaning for them. But a person's disposition to use an observation sentence is fixed by the stimulus meaning it has for him or her. Consequently, the proximal theory is right in saying that meaning is determined by proximal stimuli. 5. Objective and immanent meaning. So far, I have only considered the meaning of observation sentences. The meaning of observation categoricals-i.e. general standing sentences of the form "Whenever X, Y", where X and Y are observation sentences-can be taken to be determined by the meaning of the relevant observation sentences. This seems acceptable on both distal and proximal theories. Theoretical sentences have meaning, according to Quine, in so far as they have empirical content.34 The empirical content of a sentence can be identified with the set of observation categoricals implied by it.35 But since theoretical sentences in general do not imply any observational sentences, Quine concludes that they do not, taken in isolation, have any (empirical) meaning at all. Some theoretical sentences, notably some fairly long 33. Ibid., 81. 34. See e.g. Pursuit of Truth, 53. 35. See ibid., 17 and also "The Nature of Natural Knowledge," 80. 8 conjunctions of theory formulations, have meanings of their own, but most theoretical sentences do not. Quine writes: Unless pretty firmly and directly conditioned to sensory stimulation, a sentence S is meaningless except relative to its own theory; meaningless intertheoretically.36 However, as this quotation indicates, Quine seems to operate with two different notions of "meaning". First, there is objective or intertheoretic meaning, which is the same as empirical content. Second, there is "immanent" or intratheoretic meaning, a meaning which a sentence has "relative to its own theory". I take it that the immanent meaning of a sentence is the same as the truth condition of the sentence; truth, for Quine, is also immanent to theory.37 For example, the sentence "It's raining" means that it is raining. This is as it should be. Now, I believe Davidson is right in saying that Quine accepts a proximal theory of meaning, but I would add that this theory is exclusively concerned with objective meaning. When it comes to immanent meaning, Quine's position may be more like Davidson's. In one place, Quine writes: Davidson calls his position a distal theory of meaning and mine a proximal one. Actually, my position in semantics is as distal as his. My observation sentences treat of the distal world, and they are rock-bottom language for child and field linguist alike. My identification of stimulus with neural intake is irrelevant to that.38 Here, it might seem that Quine rejects the proximal theory. However, on my interpretation of Quine, observation sentences have both proximal (empirical, objective) and some kind of distal (immanent) meaning. Theoretical sentences have distal or immanent meaning, but in most cases they do not have any proximal or empirical meaning of their own. 6. Possible differences between immanent and distal meaning. It is not quite clear, however, that Quine's immanent meaning is precisely the same as distal meaning in Davidson's sense. Quine seems to think that it is, but I am not so sure. In particular, there are two problems with the distal theory that do not seem to arise in connection with Quine's view. The first problem has to do with the use of one and the same observation sentence on different occasions. It is natural to say, that the sentence "It's raining" has the same meaning for me when I assent to it on two separate occasions (yesterday and today, say). On the proximal theory, this is quite possible. The stimulus meaning the sentence has for me-as 36. Word and Object, 24. 37 See e.g. "Reply to Robert Nozick," 367. 38. In Praise of Observation Sentences," 114n. 9 well as my corresponding disposition to use the sentence-may be the same on both occasions. So the empirical meaning is the same. However, the distal theory seems to imply that the meaning is different on the two occasions. For, surely, the distal stimuli are different. Yesterday's rain is not the same as today's rain. Davidson writes: Meanings are shared when identical events, objects or situations cause or would cause assent and dissent.39 It is hard to see how this allows for sameness of meaning from one occasion to another. And if observation sentences have a new meaning on every occasion, it is hard to see how a person can learn their meaning. Maybe there is some way to handle this, but I have not been able to think of one. A natural move might be to say that a sentence has the same meaning on two different occasions when assent to it is caused by the same kind of event on both occasions. However, we are then faced with the problem of deciding when two events are of "the same kind". We might say that events are of the same kind if we react to them linguistically in the same way, but if so, meaning would be determined by our verbal dispositions rather than by external events. Besides, it seems two reactions should be reckoned as linguistically the same, in the relevant sense, only if the linguistic expressions involved have the same meaning, so this proposal does not really help us to define sameness of meaning. The second problem with the distal theory has to do with observational mistakes. Suppose, for example, that I am looking through the window and think I see rain outside. My sensory receptors are triggered in a way which disposes me assent to the observation sentence "It's raining". But, in fact, there is no rain. Instead, someone is watering the lawn outside the window.40 Clearly, I am mistaken. The distal stimulus, in this case, is not what I think it is. But it does not follow from this that the meaning of my sentence is not what I think it is. The meaning of the sentence remains the same in deviant cases, where assent to it is caused by events which are not correctly described by it. As far as I can see, the distal theory cannot account for this. So maybe we should conclude that there is a difference between Davidson's distal theory and Quine's view after all. When Quine says that his position in semantics is as distal as Davidson's, I think what he means is only that observation sentences "treat of the distal world" and not of proximal stimuli. But I can find no indication in Quine's work that the immanent meaning of a sentence-i.e. what is says-is somehow determined by distal elements in the chain of causes leading up to beliefs or utterances in particular cases. On the other hand, there is some indication that actual chains of causes are not are not really decisive for Davidson's theory of meaning either. In one place, he says that 39. "Meaning, Truth and Evidence," 73. My italics. 40. This particular example was suggested to me by Burton Dreben. 10 a distal theory connects meaning directly to the conditions that make sentences true or false.41 If this is taken as the central idea of Davidson's distal theory, it seems that meaning in his sense could be much the same as what I have called "immanent meaning" in Quine's theory. It should be remembered, however, that both Quine and Davidson are actually quite sceptical concerning the existence of "conditions that make sentences true or false". I take it that such conditions, if they existed, would be "facts". Neither Quine nor Davidson believes that there are such things.42 7. Davidson's argument against the proximal theory. Let us now go back to what I take to be Quine's proximal theory of meaning. As we have seen,43 Davidson's main argument against the proximal theory-viz. that it leads to "truth relativized to individuals, and skepticism"44-assumes that sentences may have the same stimulus meaning for different people. Consequently, this argument does not apply to (my interpretation of) Quine's theory. But Davidson also has another argument, which may seem more effective. It goes as follows: One might think to rescue the proximal theory, for example, by counting as stimulussynonymous sentences to which assent was prompted by different patterns of stimulation-different patterns for different people, according to the way that their nervous systems were variously arranged. The difficulty is that your pattern of stimulations and mine are guaranteed to prompt assent to distally intertranslatable sentences only if those patterns are caused by the same distal events. Such a theory would be a distal theory in transparent disguise, since the basis for translating your sentences into mine (and hence for comparing our sensory stimulations) would depend on the shared external situations that caused both our various stimulations and our verbal responses.45 The question, then, is whether Quine's theory-as I understand it-is really a distal theory in disguise. My suggestion was that one observation sentence A has the same (empirical) meaning for one speaker S1 as another observation sentence B has for another speaker S2 if and only if the stimulus meanings of A for S1 and of B for S2 are such that S1 and S2 tend to assent to (dissent from) A and B, respectively, on the same occasions. (This, I take it, is what 41. "Meaning, Truth and Evidence", p. 75. 42. See e.g. Word and Object, 246ff, and Davidson's paper "The Structure and Content of Truth," 303-4. 43. In section 4 above. 44. "Meaning, Truth and Evidence", p. 76. 45. Ibid., pp. 76-7. 11 Quine has in mind when he writes about "concurrence of witnesses".) Now, Davidson might object to this by saying that the reference to stimulus meanings plays no essential role here; and he might say that, when this reference is dropped, what is left belongs to a distal theory, not a proximal one. As far as I can see, this objection is not decisive. Of course, we may say that sentences have the same meaning for different speakers when the speakers tend to use them in the same way.46 But there is nothing particularly distal about this formulation. Sensory receptors are not mentioned, but neither are distal stimuli. A proponent of the proximal view may still insist that what determines the way a speaker uses an observation sentence is the stimulus meaning the sentence has for him. The various causal chains that lead up to the triggering of sensory receptors in different situations do not determine the meaning of the sentence. The distal causes may change-e.g. in the case of observational mistakes-even though the meaning of the sentence remains the same. 8. The conflict between distal and proximal meaning. On Quine's view, as I understand it, proximal meaning-i.e. meaning understood in accordance with the proximal theory-is something that most sentences lack. What has proximal meaning is primarily observation sentences holophrastically construed.47 In order to illustrate the conflict between the distal and proximal theories, let us consider such a sentence in the following thought experiment.48 Suppose a person has learnt to use the observation sentence "That's red" in the usual way, by conditioning. Then something happens in his environment, which results in a dramatic change: he now assents to "That's red" when the rest of us dissent from this sentence and see green things in his visual field. If the distal theory is right, we should say that the meaning of "That's red" has changed for him. It should now be translated into our language as "That's green". On the proximal theory, such a translation may be mistaken. On the proximal theory, the question is whether the stimulus meaning of "That's red" has changed. Let us assume that it remains the same as before, but that the relevant stimulations are now caused by green instead of red objects. This assumption is far-fetched, but it does not seem impossible. Perhaps a certain kind of spectacles could have this effect. Then, on the proximal view, we should say that the meaning of "That's red" remains the same for him, but that something in his environment (his glasses, perhaps) makes him have false beliefs about the color of green things. In short, the assumption is that green things cause "red" stimulations in him, but "green" stimulations in us. Now, if this is possible-i.e. if we can establish that the very 46. Compare the following statement by Quine: "There is nothing in linguistic meaning beyond what is to be gleaned from overt behavior in observable circumstances," Pursuit of Truth, 38. 47. For the distinction between holophrastic and analytic construals of observation sentences, see e.g. Pursuit of Truth, 50. 48. This thought experiment was suggested to me by Folke Tersman. 12 same stimulations that have always disposed the person to assent to "That's red", and which used to be caused by red objects, are now caused by green objects-then I suggest that the natural thing to say is that the meaning of the sentence remains the same, but that he is now systematically mistaken about the color of green objects. In other words, the proximal theory yields a more plausible verdict than the distal theory. What would happen if there were a "change" which made all of us call green things red? It is natural to say that this is inconceivable, on the ground that, if all of us call these things red, they are red. Perhaps this is not necessarily so. If our scientific theories imply that green color is correlated with certain other properties, we may want to retain these theories in conjunction with the hypothesis that our sense of color has changed so that green things now look red to us. This may be tempting for some proponent of the proximal view. On a distal theory it may be more correct to say that a change of meaning has taken place. But a more plausible description is that something has happened which forces us to modify our theories. The properties that used to be correlated with green color are now correlated with red instead. The meaning of "That's red" then remains the same on both the distal and the proximal view. I do not wish to exclude the possibility that there are cases, of the kind sketched here, in which the proximal and distal theories give different answers to the question of whether there has been a change in meaning or a change in belief. However, it seems to me that the proximal theory is at least as plausible as the distal theory in such cases, but in a Quinean spirit I would add that the disagreement between the two theories in such cases does not concern any real fact of the matter. 9. Empiricism and skepticism. At this point, let us leave the theory of meaning and return instead to epistemology. In particular, let us return to the third dogma of empiricism mentioned in sections 1 and 2 above. Davidson's main argument against this dogma-and thereby against empiricism-has to do with its emphasis on an intermediate epistemic level between the world and our theory of the world. This intermediate level consists of empirical content; in Quine's case it is the triggering of sensory receptors. Davidson claims that the introduction of such an intermediate epistemic level leads to skepticism. In a talk in Stockholm in 1993 on Quine's philosophy, he recalled his early reaction to "Two Dogmas", and its "distinction between a non-propositional content given in experience and a conceptual scheme, language, or framework which organizes that content". And he went on: This distinction, characteristic both of Kant and many empiricists, spells trouble only if the "given" element is assigned a subjective epistemic role; in that case, there is an epistemic intermediary between the world which (we assume) causes our sensations 13 and our conceptualization of the world. The trouble I see in such an epistemology is that it leaves no escape from skepticism of the senses, for we can always wonder whether the world is the way we imagine it to be or whether we're just getting the impressions we would be getting if the world were that way. [...] A completely familiar problem; but wasn't Quine hinting that he would be satisfied with the "as if" position by calling physical objects "posits"?49 And again, a few pages later: Unless we are willing to settle for the skeptical view that success in predicting our future (observational) beliefs is all there is to having a true view of the world, we need a theory of meaning and an epistemology that somehow ties the contents of speech and thought to the situations and objects we take those contents to be about.50 But the skeptical question Davidson imagines of "whether the world is the way we imagine it to be or whether we're just getting the impressions we would be getting if the world were that way" is, I believe, ruled out by Quine's naturalism. It seems that this question makes sense only if there is a higher tribunal of truth than science, but the existence of such a higher tribunal is precisely what Quine's naturalism rules out. Truth, for Quine, is immanent. Facts are also immanent.51 There is no Ding an Sich which is forever beyond the reach of science.52 The only way in which we can be mistaken about the world is the way in which science itself sometimes shows us that we are mistaken. In the quotation above, Davidson also refers to "the skeptical view that success in predicting our future (observational) beliefs is all there is to having a true view of the world". He seems to imply that this is not Quine's view. However, I believe, on the contrary, that something like this is indeed Quine's view, and I also believe that this view is not a skeptical one. Let me quote a few passages from Quine, which seem to support this interpretation: [...] systematization of our sensory intake is the very business that science itself is engaged in.53 The scientific system, ontology and all, is a conceptual bridge of our own making, linking sensory stimulation to sensory stimulation.54 49. Davidson, "On Quine's philosophy," 187. 50. Ibid., 190. 51. See e.g. "Reply to Robert Nozick," 367. 52. See Theories and Things, 22. 53. From Stimulus to Science, 15. 54. Theories and Things, 20. 14 From impacts on our sensory surfaces, we in our collective and cumulative creativity down the generations have projected our systematic theory of the external world. Our system is proving successful in predicting subsequent sensory input. [...] Not that prediction is the main purpose of science. [...] Prediction can be a purpose too, but my present point is that it is the test of a theory, whatever the purpose.55 Our scientific theory can indeed go wrong, and precisely in the familiar way: through failure of predicted observation. [...] Our overall scientific theory demands of the world only that it be so structured as to assure the sequences of stimulation that our theory gives us to expect.56 These quotations indicate that Quine accepts the view that the world is, in a sense, a human construction or projection (a "posit"). But this view does not have any skeptical implications. On the contrary, the very idea that the world is a human construction rules out the possibility that we may be massively mistaken about the world. The nature of the world is specified in our theories, and there is no truth independent of these theories. As mentioned above, truth, for Quine, is immanent; but this immanence of truth is no limitation. Within our own total evolving doctrine, we can judge truth as earnestly and absolutely as can be; subject to correction, but that goes without saying.57 It is not just that our judgments concerning what is true have to be made from the perspective of our total evolving doctrine; truth itself is determined by this doctrine. The term "the world" (or "reality") has no meaning outside our total system of the world. We must "recognize 'real' as itself a term within our scientific theory".58 Accordingly, there is no truth and no reality independent of this system; "it is within science itself, and not in some prior philosophy, that reality is to be identified".59 10. Sensory evidence. However, Davidson would still insist that it is illegitimate to assign an epistemic role to sensory stimulation. He agrees that sensory stimulation plays a causal role in the production of beliefs, but he does not accept Quine's view that "whatever evidence there is for science is sensory evidence". Davidson writes: 55. Pursuit of Truth, 1-2. 56. Theories and Things, 22. 57. Word and Object, 25. 58. "Reply to Hookway," 504. 59. Theories and Things, 21. 15 [...] our experimentation bears no epistemological fruit except as it causes us to add to, cling to, or abandon our beliefs. This causal relation cannot be a relation of confirmation or disconfirmation, since the cause is not a proposition or belief, but just an event in the world or in our sensory apparatus. Nor can such events be considered in themselves to be evidence, unless, of course, they cause us to believe something. And then it is the belief that is properly called the evidence, not the event.60 It is not clear to me why it would be improper to use the term "evidence" for some event- such as proximal stimulation-in the causal sequence leading up to belief. Maybe this use is not very common, but Quine for one does seem to use the term this way, for example in the following passage: The stimulation of his sensory receptors is all the evidence anybody has to go on, ultimately, in arriving at the picture of his world.61 However, it might be argued that Quine has changed his view in his more recent writings. For example, Roger Gibson, who is one of the leading interpreters of Quine, has said that on Quine's "new view", observation sentences are causally but not epistemically related to neural inputs.62 On an earlier occasion, Gibson said that (for Quine) "[t]he stimuli related via conditioning to the observation sentences constitute their evidence".63 This indicates that Gibson believes that Quine has changed his mind on this point. Personally, I am not so sure. In one fairly recent answer to Davidson, Quine says of surface irritation that its proper role is as "a basis not for truth but for warranted belief".64 Anyway, the substantial question is whether or not proximal stimuli can play an epistemic role in addition to their causal role. It seems to me that they can. I suggest that Quine might still be willing to accept some principle like the following: (E) A person P is justified, ceteris paribus, in assenting at t to observation sentence S, if P at t has the capacity to use S in a competent way, and if P is subject to neural input which is included in the (affirmative) stimulus meaning of S for P at t. I suggest that (E) is an element of Quine's empiricism. It seems to me that (E) may be the very point at which Quine and Davidson differ-if they differ. Davidson would certainly reject (E), but Quine might accept it. This is what makes Quine an empiricist and Davidson an anti-empiricist. 60."Empirical Content," 486. 61. "Ontological Relativity," 75. 62. See Roger Gibson, "Quine and Davidson: Two Naturalized Epistemologists," 458. 63. Enlightened Empiricism, 54-5. 64. "On the Very Idea of a Third Dogma," 39. 16 Moreover, I believe that (E) is one of the grounds for the special status of observation sentences in Quine's philosophy. (The other ground is the intersubjectivity of observation sentences.) For Quine, observation sentences play a role "as vehicles of evidence for our knowledge of the external world", as follows: We are not aware of our neural intake, nor do we deduce anything from it. What we have learned to do is to assert or assent to some observation sentences in reaction to certain ranges of neural intake. It is such sentences, then, thus elicited, that serve as experimental checkpoints for theories about the world. Negative check points.65 Of course, the ceteris paribus clause in (E) is essential, for a person may have good theoretical reasons for dissenting from an observation sentence even though he is subject to stimulation which belongs to its (affirmative) stimulus meaning. But observation sentences have an epistemologically privileged status. By contrast, according to Davidson, if I understand him correctly, observation sentences have no special privileged status; in particular, we are not justified in assenting to them simply because we are subject to the appropriate stimulation. Davidson writes: In my view, erasing the line between the analytic and synthetic saved philosophy of language as a serious subject by showing how it could be pursued without what there cannot be: determinate meanings. I now suggest also giving up the distinction between observation sentences and the rest. [...] Accordingly, I suggest we give up the idea that meaning or knowledge is grounded on something that counts as an ultimate source of evidence.66 In particular, then, knowledge is not grounded on sensory evidence. Davidson is a coherentist, and "the coherentist will hold that there is no use looking for a source of justification outside of other sentences held true".67 For Davidson, neural input is not an ultimate source of evidence. It is not a source of evidence at all. 11. The justification of observational beliefs. On Davidson's coherentist view, you may of course have evidence for observational beliefs; in other words, you may be justified in holding true, or assenting to, observation sentences. But, on a coherentist view (of Davidson's type), the evidence for an observational belief can only be some other belief or beliefs.68 65. "In Praise of Observation Sentences," 110-1. 66. "A Coherence Theory of Truth and Knowledge," 313. 67. Ibid., 312. 68. See ibid., 310. 17 In other words, Davidson is an internalist about justification and evidence, while Quine-if I understand him correctly-is an externalist.69 For Davidson, all the evidence you can have for a belief is internal to your system of beliefs. For Quine, much evidence is indeed internal to your system of beliefs, but there is also an external source of evidence: the triggering of your sensory receptors. In order to illustrate the external position consider the following thought experiment. I am sitting in my office looking out through the window. As it happens, there is no rain outside. However, unknown to me, someone is manipulating my nerve endings by some kind of remote control in such a way that I get a stimulation which is included in my positive stimulus meaning of "It's raining". So I believe that it is raining. Now it seems that, in this case, I am justified in believing that it is raining, even though I am mistaken. I have been educated in the use of the sentence "It's raining", and the education has been completely successful. I am a fully competent user of the sentence, and there is nothing wrong or blameworthy about my use of it in this particular situation. It is only that the situation has been rigged in a way that fools me. But from an epistemic point of view, I have made no mistake. My belief is justified. This fits well with (E). Compare this with a situation where someone manipulates, not my nerve endings, but the interior of my nervous system. Now the stimulation I get is not included in my positive stimulus meaning of "It's raining", but the end result is the same: because of the manipulation, I believe that it is raining. In this case, it seems that my belief is not justified. The reason is that in this case the manipulation affects me in such a way that I am no longer a competent user of the sentence. My very competence is lost. Hence, my belief is unjustified. Again, this fits well with (E). In the case of observation sentences, truth conditions and assertability conditions seem to coincide. However, we should distinguish between two kinds of assertability conditions: recognizable and physiological. (The latter are objective physical states of the speaker's organism.) When I learn the sentence "It's raining", I acquire the practical ability to recognize the conditions under which this sentence is true. I also learn that the conditions under which the sentence is true are conditions under which I am justified in asserting or assenting to the sentence. These conditions are recognizable. They are also immanent to my language. However, there are also physiological (objective) assertability conditions. Surely, I am justified in assenting to "It's raining" when I have learnt to use the sentence correctly-by having gone through a suitable and successful conditioning process-and my sensory receptors are stimulated in a relevant way. In such a case, my assent is justified, but what I assent to may be false. The principle (E) ties my personal state of justification to the social learning process which explains my disposition to use the sentence in question. When I have learnt to use the sentence "It's raining" correctly, i.e. to the satisfaction of my peers, I am 69. For the distinction between externalism and internalism, see e.g. Dancy and Sosa, A Companion to Epistemology. 18 justified (ceteris paribus) in assenting to it on those very occasions on which I do assent to it. This is precisely what successful learning results in. At later stages in my education, when my theory of the world has grown into a more mature and sophisticated system, I may also be able to justify my belief that it is raining, on a certain occasion, in more indirect ways, namely by inferring it from certain other beliefs that I have. For example, I may be able to infer it from beliefs concerning my subjective cognitive states, the reliability of my sensory organs, the relation between my cognitive states and my sensory organs, and beliefs about what would be the best explanation of certain cognitive states. Moreover, with greater sophistication I will also learn that my immediate assent to observation sentences is sometimes mistaken. I learn that there are sometimes theoretical reasons for rejecting observation sentences which would otherwise be appropriate on a given occasion. But these complications are quite compatible with principle (E). In conclusion, then, I want to side with Quine when he replies to Davidson that "[t]he third purported dogma [of empiricism], understood now in relation not to truth but to warranted belief, remains intact. [...] It is what makes scientific method partly empirical rather than solely a quest for internal coherence".70 70. "On the Very Idea of a Third Dogma," 39. 19 Bibliography Bergström, Lars. "Quine's Truth." Inquiry, 37, December 1994, 421-35. – – – . "Quine, Empiricism, and Truth." Forthcoming in Alex Orenstein and Petr Kotatko (eds.) Knowledge Language and Logic. Kluwer Academic Publishers. Dancy, J. and E. Sosa (eds.) A Companion to Epistemology. Oxford: Blackwell 1993). Davidson, Donald. "On the Very Idea of a Conceptual Scheme." 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