Michael Devitt's Realism and Truth (Devitt 1991, henceforce RT) proposes a strong and interesting defense of Common-Sense Realism and Scientific Realism. basically he argues that if we choose naturalized epistemology, we cannot be anti-realists. My purpose in this paper is to analyze his argument critically by comparing it with Arthur Fine (1986a, 1986b)'s 'natural ontological attitude' (NOA). My conclusion will be that despite Devitt's own claim, his argument fails to show we have more than natural ontological attitude.
Section 2 summarizes Devitt's own argument for Common-Sense Realism and Scientific Realism. Section 3 deals with Fine's NOA. In section 4, I shall show how Devitt's argument is inadequate as a support of realism. In section 5, we will see where the above analysis leads us.
Devitt's argument for realism is based upon several methodological maxims. Among these maxims, the most important and characteristic one in his argument is Maxim 3: "Settle the realism issue before any epistemic or semantic issue" (RT, 4). There are several arguments to defend this maxim. First, as we will see soon, Devitt argues that if we start from epistemology, we end up with instantaneous solipsism (75). We have much more knowledge in ontology (by physics, biology and so forth) than in epistemology or semantics (232). Moreover, since epistemology and semantics are problems about people and language, they are just a tiny part of the comprehensive theory of the world provided by science (232, 284). Therefore, to start from semantics is to "put the semantic cart before the realist horse" (4). I think that this is one of the most controversial claims in this book, and in some sense the purpose of this paper is to analyze the consequence of this maxim. Anyway, appealing to this maxim 3, he starts from naturalistic ontology of science to arrive at naturalized epistemology.
In chapter 2 of RT, Devitt clarifies what he means by "realism." Basically his realism has two dimensions, i.e., the independence dimension and the existence dimension (RT 14-22).
The independence dimension of realism says that the world and entities exist objectively, external to and independent of us. But what does the phrase "independent of us" mean? According to Devitt, this means that "it is not constituted by our epistemic values, by our capacity to refer to it, by the synthesizing power of the mind, by our imposition of concepts, theories or languages" (RT, 15). There are several important features in this definition. First, the world is not unknowable. Second, mere objectivity is not enough for independence, because mental object can be objective (to make this point clear, Devitt introduce the expression to exist "independently of the mental"; 20). Finally, the world can exist unobserved.
The existence dimension of realism is that to be a realist one should commit to not only the existence of external world, but also "structured set of entities" (RT, 17) in the world. Actually Devitt thinks that this is still weak, and he claims that the realism that is worth fighting for holds that "we are more or less right" in the common-sense and scientific entities we posit (18). But he adds an interesting qualification. The common-sense and scientific theories change from time to time. From our point of view all ontologies posited by past scientific theories are more or less wrong. Similarly, our own ontologies may seem to be wrong from future scientific theories' point of view. Then, which ontology should realists support? To answer this, Devitt introduces the notion of "realism (t)", which means realism about the ontology at time t (20). According to him, what realists should fight for is realism (now), ontology of our current scientific (and everyday) theories (I will discuss the implication of this time relative notion of realism later). Devitt also argues that we do not have to commit the existence of type, even though when we express our ontological commitments we need to use type words (20-21).
With these consideration, Devitt formulates his Realism with capital R as follows (RT, 23):
Tokens of most current common-sense and scientific physical types objectively exist independent of the mental.
As subdivision of this Realism, Devitt introduces the distinction between "Common-Sense Realism" and "Scientific Realism" (25-26). Common-sense realism is realism on the observable entities, and scientific realism is on non-observable entities.
Before we move to his defense of this view, we should note one characteristic of this definition of Realism. He does not use the notion of truth to define realism. This shows a strong contrast with some of the influential definitions of realism (e.g., van Fraassen 1980, 8). In this sense, in Hacking's terminology, this is "realism about entities," not "realism about theories" (Hacking 1983, 27). This is in accord with maxim 3, because, if he uses the notion of truth in the definition of realism, he should settle the matter of the truth (i.e. semantics) before the realism issue.
Devitt's argument for Common-Sense Realism is rather indirect one. He shows that the sceptical doubt of Realism is a very strong position, but because of this strength, the sceptical doubt becomes uninteresting. Once we dismiss the doubt, we can safely start from naturalistic ontology, and this ontology is realistic, we get realism.
First, Devitt formulates the Cartesian sceptical problematic. It insists that "the Realist is justified in his belief only if he can give good reasons for eliminating alternative hypotheses to Realism" ( RT, 62). To make this problematic plausible, Devitt adds two qualifications (61-62). First, the sceptics are not requiring absolute certainty; otherwise, it is too strict to be an interesting question. Rather sceptics are requiring good reason to eliminate other alternatives. Second, sceptics themselves are not committing any belief. They are just exploiting the premises in Realism to do reductio from the premises. Then, what are the alternatives to Realism? Descartes himself offered some in the first meditation (Descartes 1642/1971); Our senses may totally deceive us; we may dreaming; there may be a Deceitful Damon who make us believe the existence of the world. Therefore, according to the sceptical problematic, if we fail to eliminate these alternatives, Realism is not justified.
Devitt distinguishes four different kinds of reply to the challenge. First, there are various kinds of foundationalisms (RT, 65-71). Devitt runs through sense-data theory, Lockean representative realism, phenomenalism, and dismisses all of them as failing to answer the sceptics. Second group of replies is Kant's view and other constructivisms influenced by Kant (71-73). Devitt offers two interpretation of these views, and shows that under the first interpretation Kantianism shares the problems of other foundationalisms, and under the second interpretation its metaphysics becomes too mysterious to believe. Third reply is instantaneous solipsism, which admits nothing other than the belief that the person is now experiencing. This is "a doctrine that is literally incredible" (75), and Devitt illustrates this point with an example of a logician who wrote a letter saying that she was a solipsist (64). Fourth reply is Devitt's own reply, namely, naturalized epistemology.
Devitt diagnoses that the failure of previous tries comes from their starting point, namely a priori epistemology. Rather, "[w]e should use the empirical method, not the a priori one, and should set scepticism aside" (RT, 73, emphases original). In other words, the failure of previous tries shows that the sceptical problematic sets the standard too high, so we should stop trying to answer sceptics and constructing a priori epistemology; "[s]cepticism is simply uninteresting: it throws the baby out with the bath water" (75). The alternative Devitt provides is naturalized epistemology described by Quine (1969). According to Devitt, "[n]aturalized epistemology takes science, and hence its posits pretty much for granted" (RT, 76). Science as it stands is thoroughly Realist, at least on observable entities. So we become Common-Sense Realists just taking this alternative (though Devitt does not deny the possibility we can reconsider Realism from this position; ibid.). From this point of view, epistemology is an empirical enterprise on our psychological process. Normative epistemology is also a part of science, because to find out a reliable method we should know the relation between the world and human beings before that. In short, "we use our view of what is known to arrive at our view of the knowledge process" (79). This is, of course, in accord with his maxim 3.
Obviously this argument is somewhat circular. He dismisses the sceptical problematic because there is no available Realistic answer to it, and adopts naturalized epistemology because it allows us to be Realists. How can Devitt justify this move? His answer is "Realism is the only theory in town" (73, emphasis original). All other attempts failed, and instantaneous solipsism is not an alternative at all, so actually we have no choice other than being a Realist. He also gives an argument by abduction, and we will consider this view in the next section.
So far, his argument is on the reality of common-sense objects, including observable scientific objects. But what about unobservable objects like electrons and so forth? Devitt's defense on this point heavily depends on abduction. So we need to look at his argument for it carefully.
2.4.1 Argument for abduction
Devitt gives his arguments for abduction in several different places. First, he attempts a defense of Common-Sense Realism by abduction (RT, 73-75). He considers following statement in as-if language:
It is as if there is a black raven on the lawn.
This statement itself just describes the experience without positing the existence of raven. But what is the explanation of this experience? The obvious answer is that there is really a black raven on the lawn. This conclusion is supported by the fact that there is no available experience language (i.e. a language which describes experience without positing existence) other than this kind of 'parasitic' language. In this case Realism is the only alternative, and this inference to Realism is abduction.
Devitt's argument for Scientific Realism (Realism on unobservables) is basically on the same track as his use of abduction for Common-Sense Realism (RT 108-110). He uses abduction to infer the existence of unobservables. The argument is simple: "[b]y supposing they [unobservable entities] exist, we can give good explanations of the behaviour and characteristics of observed entities, behaviour and characteristics which would otherwise remain completely inexplicable" (108). The difference between two kinds of abduction is not so significant. Both go beyond experience (in the case of observables, it goes beyond as-if language), both infer entities which have never observed (most observable entities have never been observed). So if someone accepts abduction for observables, there is no reason the person cannot accept abduction for unobsevables (110).
Devitt considers several objections to abduction. First, he discusses Cartwright's and Hacking's criticisms. Basically what Devitt finds is that both Cartwright and Hacking use some kind of abduction for their own version of realism, so their attack is very limited. Devitt understands their argument as "saying something about what abductive arguments are and when they are good" (113). I shall discuss Hacking's criticism and Devitt's reply later in detail. Another objection to abduction Devitt discusses is van Fraassen's argument (139-142, 147-149). Devitt's strategy against van Fraasen is simple. Van Fraassen tries to be a realist about observable and at the same time anti-realist about unobservables. Devitt shows that this distinction does not make sense when it comes to abduction. Devitt also adds another point for abduction: It is not obvious that empiricism alone cannot count as against abduction (148-149). Empiricism is a general position that experience is the only legitimate source of information about how we should learn about the world. And it is possible that experience shows us abduction is a good way to learn about the world. If so, abduction is compatible with empiricism.
2.4.2. Underdetermination
Above summary is enough to outline Devitt's argument for Realism. But Devitt also provides many minor arguments to answer anti-realists' attack. I would like to look at his argument against underdetermination (RT117-121) before we finish up this section.
Underdetermination is a thesis that for any theory there are always empirically equivalent but ontologically incompatible other theories. If this thesis is true, it may undermine the reason we commit to the posits of the theory, thus undermine Scientific Realism. Devitt tries to show that this thesis is not true in any interesting sense.
The baseline of Devitt's argument is that for any pair of empirically equivalent rival theories, we could come up with some set of auxiliary assumptions which yields different predictions when it is conjoined with the rival theories in turn (118). Devitt does not tell us how exactly we can find such assumptions, but he has some supportive arguments. First, if we can rely on our capacity to create empirically equivalent theories, there is no reason we can not also rely on our capacity to create auxiliary hypotheses to discriminate them (118). Second, we should not overlook our capacity to create phenomena. So when we talk about empirical equivalence, we should count not only the possible evidence we could passively observe, but also the possible evidence we could actively create. It is incredible that two theories are totally indistinguishable in this strong sense (119-120).
Now we should turn to Arthur Fine's argument (1986a, 1986b). Fine's argument for natural ontological attitude has two aspects. One is the diagnosis of realism debate, and the other is proposal of NOA as a remedy. we will notice there are some similarities between Devitt's and Fine's arguments, along with some strong contrasts.
Fine characterizes scientific realism in three features; (1) belief in a definite world structure; (2) belief in the possibility of substantial epistemic access to that structure; (3) science aims at all the epistemic access to the definite world structure that realism holds to be possible (Fine 1986a, 137). Antirealism is supposed to oppose all of three tenets (ibid.). Fine severely criticize both sides of the debate.
Fine's first target is realism (by realism Fine almost always means scientific realism). According to Fine, realists maintain that the only adequate way to explain the success of scientific methodology is on the basis of realism (Fine 1986a, 113-114). But this abductive reasoning is begging the question. When we see realism as an explanatory hypothesis of scientific practice, maybe it is true that this hypothesis has an explanatory efficacy. But to conclude that therefore realism hypothesis is likely to be true, we need another premise, i.e. an explanatory efficient hypothesis is likely to be true. But this premise is exactly a part of what we should show by this argument (114-115). Inductive argument for realism does not work either, because for inductive generalization we need to have observable connections between observables, but in the case of the realism hypothesis, neither reality itself nor the relation between reality and observable is observable (115-116). Even the alleged success of scientific methodology is questionable. History of science shows that science fails for the most part. Therefore, "[t]he problem for the realist is how to explain the occasional success of a strategy that usually fails" (119, emphasis original).
Another way Fine uses to put the same point is to compare realist explanations with instrumentalist ones (Fine 1986b, 153-156). Fine's conclusion of the comparison is summed up as a metatheorem: "If the phenomena to be explained are not realist-laden, then to every good realist explanation there corresponds a better instrumentalist one" (154). For every time realist use the word 'truth' for the explanation, instrumentalist can replace it with 'instrumental reliability.' Because instrumental reliability of a theory is enough for explaining the success of the theory, and to add "the theory is also true" does not add any explanatory power, the instrumentalist explanation is enough, and better in the sense that it does not have the superfluous mention to the truth. We will come back to this argument later.
The above arguments are all against realism about theories, not against realism about entities. Fine does not spend much time to analyze realism about entities, and his argument on this point is directed to Hacking (1983). Hacking maintains that if we can successfully build an instrument using an entity, it exist. But, Fine opposes, neither the behavior of the instrument nor the ease of discourse about the behavior shows the object is real, but they just show "what is already taken for granted" (Fine 1986b, 164). This is evidence for the instrumental reliability of what we take for granted, but nor for the existence of it (by the same reason as the above metatheorem).
But why realism is so unsuccessful? Fine's diagnosis is that the problem is in their attitude. "The realist...tries to stand outside the arena watching the ongoing game and then tries to judge ... what the point is," but "he cannot (really!) stand out side the arena," because "we are in the world, both physically and conceptually" (Fine 1986a, 131).
All these arguments seem to show that Fine is an antirealist. But he also attacks antirealism. Since my purpose of this paper is the contrast with Devitt, however, I do not want to spend much time on this issue, so I just make some short remarks on this point. Fine's objection to antirealism is that it is a kind of inflationalism in the same sense that realism is a kind of inflationalism (Fine 1986b, 166-171). Inflationalism is "to interpret science in accordance with a set of prior, extra-scientific commitments" (Fine 1986b, 171). There is no ground for such extra-scientific commitments. Instrumentlism is inflationalism because it introduces the notion of instrumental reliability as a sole criterion of theory choice without having any argument for it (Fine 1986b 166-171)[2] . His attacks on Putnam's (1981) and others' 'acceptance theory of truth' (Fine 1986a, 137-142) and van Fraassen's (1980) distinction between observable and unobservable (Fine 1986a, 142-147) are all on this track.
The above diagnosis has already shows where Fine is heading. He blames both realism and antirealism for introducing some unwarranted commitments. What if they add nothing to what they can agree? This is what Fine calls the "core position" (Fine 1986a, 128). According to Fine, "both realists and antirealists accept the results of scientific investigations as 'true,' on par with more homely truths" (ibid.). More concretely, they agree that "there really are electrons, and that they really carry a unit negative charge and really do have a small mass (of about 9.1*10-28 grams)" (129). What antirealists add on the core positon are particular analysis of the concept of truth. Then what do realists add on it? According to Fine, it is "a desk-thumping, foot-stamping shout of 'Reality'" (ibid.). (This is a really improtant point in his argument, and I shall devote a considerable part of my analysis for the understanding of this statement. ) Now, Fine's proposal is to stop adding anything, and take the core position as it is. This is what he calls NOA, natural ontological attitude (130).
What is the reason he endorses this position? He call it "homely line" argument (Fine 1986a 126-127). First, we naturally trust our sense on the whole. We also have similar confidence in the safeguard systems of scientific investigation. This lead us to trust scientists. So if they tell us that there really are molecules, we must accept that. This means we had better be realists. Fine sums up this argument as follows: "it is possible to accept the evidence of one's senses and to accept, in the same way, the confirmed results of science only for a realist" (127, emphasis original). So we have same attitudes to everyday truth and scientific truth. But this realism does not refer to external world, because to refer to external world we should step outside of the picture and relate our notion of reality with external world, but this is impossible. In this respect NOA parts with realism. But NOA rejects antirealistic interpretations of science, by the reason already mentioned in the previous section. So talks about the meaning of scientific statement or about the aim of science are all irrelevant, or at least questioned (Fine 1986b, 172-173). As a result, Fine takes 'truth' as a primitive concept, and calls this "'no-theory' conception of truth" (Fine 1986b, 175).
A remaining question is how we can study science without such clear cut notions employed by realists and antirealists. Fine's answer is that we should give up essentialism and study science empirically as a historical entity (Fine 1986b, 172).
As the summaries in section 2 and section 3 show, Devitt and Fine share some naturalistic approach to science. But Fine denies the metaphysical reality of the objects of science, while Devitt claims it is indispensable. Where does this difference come from?
I think that one possibility is that Devitt implicitly introduced some unwarranted premises in his argument (another possibility is that the difference is just a matter of way of speech). I try an analysis along with this line. First, I evaluate Devitt's argument against the sceptical problematic, and introduce revised version of the problematic. Then I compare their starting points, "taking science for granted" vs. core position. I show core position is sufficient for avoiding the sceptical problematic in Devitt's sense. Finally, I show that, under the assumption of maxim 3, naturalized epistemology cannot lead to Realism. Devitt's arguments for abduction and against underdetermination are interesting, but they will not help very much in this respect.
To understand the difference between the starting points of Devitt and Fine, first we should look at the way they arrive at the starting point. To some extent, their strategies are similar. Both of them start from eliminating other alternatives, and propose their own position as a viable alternative. But while Fine's argument against realism depends on pointing out the circularity of realists' arguments, Devitt's argument against the sceptical problematic is supposed to justify such circularity. Thus if Devitt's argument is sound, it undermines Fine's attack. So let us look at how Devitt's argument is or is not successful.
First of all, we should evaluate the extent traditional attempts to answer scepticism have failed. Now we should recall that Devitt has added a qualification to scepticism; namely, sceptics are not requiring absolute certainty, but good reasons to believe (RT, 61). This means that it is not enough for sceptics to raise an alternative possibility like Deceitful Damon, but they should also these are reasonable doubts. If traditional alternatives fail to eliminate these reasonable doubts, they fail to answer sceptics. But curiously enough, in his assessment of traditional alternatives, Devitt never goes through this procedure, and is content with showing just that there are always possible replies from sceptics (e.g. 66, 67). Actually in this case the assessment of failure hinges upon the degree of 'reasonableness' we require to sceptics. We need very detailed analyses, and Devitt's arguments are apparently not enough.
Even though we admit that all alternatives have failed, Devitt's next move is not warranted either. Devitt claims that Realism is the only theory in town, but this is not the case. To see this, please recall in what sense alternatives have failed. They failed in answering to sceptics. Now, what Devitt proposes is to set scepticism aside. But this move cancels the failure of traditional alternatives, because they no longer have to answer to sceptics! To put slightly different way: if we accept the sceptical problematic, no viable position (including Realism) is available; if we do not accept the sceptical problematic, almost all positions (including traditional answers) are available. In any case, it is not the case that Realism is the only theory in town[3] . Of course this anarchy is not what Devitt wants. He might reply that because we adopted naturalistic problematic, other alternatives are eliminated by scientific consideration. But this does not help much. Locke might say that he adopts Lockean problematic, phenomenalists that they adopted phenomenalistic problematic, and that from their points of view naturalized epistemology should be eliminated.
How can we avoid this anarchy? I think the answer is in the way Devitt confined the sceptical problematic. As we saw above, we can play with the degree of 'reasonableness' we require to sceptics. If we admit almost implausible sceptical assumptions, theories should have high degree of certainty to answer it. The other extreme is to require absolute certainty to the sceptical doubt (I mean, sceptics cannot mention Deceitful Damon without showing the existence of such Demon with absolute certainty), and in this case almost all theories are admissible. We can change the required degree of certainty between these two extremes, and apparently if we set the required degree of certainty reasonably high, we can rule out many implausible alternatives. Now, here is the revised sceptical problematic: choose the theory which has the highest degree of certainty (i.e. requires the lowest degree of reasonableness to the sceptical doubt) among viable alternatives. Even though I think that naturalized epistemology should keep high certainty compared with other alternatives, I have no reason to assume this is the most plausible theory. It is a matter of further analysis. Also please notice that this problematic does not exclude circular justifications, because, for example, if all viable alternatives are circular, we should choose the most certain (circular) argument. Anyway, this problematic is not uninteresting at all.
This analysis also shows that just suggesting sceptical possibility does not necessary mean the person is in the sceptical problematic in Devitt's original sense. If the person can give a reasonable ground for the sceptical doubt, the possibility is that she is playing my revised version of the sceptical problematic. Now, what about Fine's argument? Sometimes his argument sounds like playing the sceptical game (see, for example, his argument against realism about entities; Fine 1986b, 164). But what he shows is that empirically speaking realist account and instrumentalist account have same plausibility. Maybe he is wrong, but important thing here is that he is not playing the "uninteresting" sceptical problematic, so Devitt can not dismiss his argument by that reason. I think this is more than enough to proceed to the next step to compare their starting points.
Now, it is time to examine the ontological commitments of Devitt and Fine. To quote again, Devitt says that "[n]aturalized epistemology takes science, and hence its posits pretty much for granted" (RT, 76), and Fine says that NOA "accept the results of scientific investigations as 'true,' on par with more homely truths" (Fine 1986a, 128). One important difference between two attitude is that while Devitt's commitment make him a Realist, Fine denies that it commits him something about external world. How should we understand this difference?
As far as we speak in first person language, there is no way to make sense of the distinction between NOA and Realism, because we cannot step outside of our own world and take a look at of the external world. This may sound like we need God's eye view, but to make sense of Fine's argument, we do not have to go so far (in this way we can avoid some objections by realists; see McMullin 1991 and RT 232). Let us imagine that we are looking at people's ontic commitments from out of the picture, and see what is going.
It seems to me that difference between Fine and Devitt can be expressed in the following distinction:
(a) people take their ontic commitments for granted.
(b) people take the objects of their ontic commitment for granted.
Next two subsections examine these two options respectively.
4.2.1 (a) taking ontic commitments for granted
I mean by "taking ontic commitments for granted" some totally psychological process. Ontic commitments involve to learn to use some kind of sentence (like "electrons exist" "electrons are independent of us"), appropriate attitude to some related experiences, associate some mental picture to the sentences (see figure 1), and so forth. So just assume that taking a ontic commitment for granted means to adopt these piecemeal attitude (somewhat) uncritically. One might oppose that such an assembly of piecemeal attitudes cannot make a true ontic commitment. Fair enough. But what is the difference between a true believer and those who have such an assembly of piecemeal attitude? As Schlick (1932/33) suggests, this difference can be also described as a psychological attitude (52-53). So what we should do is to add this attitude to the list. By taking this commitment for granted, a person becomes a 'realist' from the first person's point of view. But at the same time, this 'ontic commitment' is attained without referring the object of the commitment. So from our third person's point of view, it is obvious that this attitude, as it stands, is not about some entities in the world, and therefore the attitude cannot count as a Realist. Moreover, if the people themselves reflect upon what they are doing, they would admit this whole thing has nothing to do with external world, just by imagining this third person's view.
What is the merit of taking this kind of position? Please remember that the primary reason Devitt prefers naturalized epistemology is that any other reply ends up with instantaneous solipsism (RT p. 75). Then what was wrong with instantaneous solipsism? It is incredible. Now, the position I described does not have this flaw. By taking ontic commitments for granted, people can behave just like Realists. To complete the picture, let us assume that people also adopt other attitudes about how to change ontic commitments (in response to experience, maybe). These attitude can work just like inference rules, without referring the object of ontic commitments. As far as our everyday life and scientific investigations are concerned, we can reconstruct everything this way. In this sense, this option is a viable alternative. I think that this is what Fine called 'core position.'
Sometimes Devitt himself sounds like suggesting this position: "we use our view of what is known to arrive at our view of the knowledge process" (RT, 79) Here he is talking about the relation between two "view"s. As far as we take the first view for granted, and as far as the first view implies some methodology to arrive at the second view, we need no reference to the external world. But of course Devitt resists this interpretation. In section 5.9 of RT he rejects the possibility that naturalized epistemology is compatible with anti-realism (79-80). The first difficulty he proposes is that "our ordinary scientific theory, as it stands, is thoroughly Realist" (79). Therefore, if we want to be an anti-realist, we should revise our theory. He proceeds to show that we have no reason to do such a revision in favor of sense data theory, once we abandon the sceptical problematic (80). He also argues that such a revision should be very strong revision, because our theory on the physical world cannot be translated into phenomenal language (ibid.). But our above argument casts a doubt on the very premise of his argument. Are scientific theories realistic? It is true that scientists express their ontic commitments on "electrons," "quarks," and so on, but just to have these attitudes does not mean that the attitudes are about electrons and quarks out there. I think this is, to some extent, a matter of empirical research. Let me cite an impressive research by Piaget (1954). According to Piaget, we are not born with the concept of external object, but we learn it in the first two years of our life. When an object vanishes from a child's sight and reappears, at first the child reacts as if it is a totally new object. Later the child learns to seek for vanished object. This seems to show that we start our life as Barkeleyen antirealists (cf. Berkeley 1965; see also RT, 69-71), and later convert to realism. By examining this process, we would be able to assess what kind of realist (NOA or Realist) we converted to, and if the conversion is legitimate. At least we cannot just assume that we are on the realist boat from the outset.
4.2.2 (b) taking objects of ontic commitment for granted[4]
By 'taking objects of ontic commitment for granted,' I mean adopting commitments about the entities in the world. Apparently these commitments make people Realists. But what is the difference between this position and the position described in the previous section?
Let us look at the situation from the same third person's point of view. At the first glance, the situation seems to be the same. The people observed seem to adopt certain attitudes, to change their attitudes according to certain rules, and so on. But somewhat all of these things are supposed to be about some external entities. But how?
One obvious answer is to appeal to the correspondence theory of truth. Because of the correspondence between their utterances of "electron" and electrons out there, all attitudes related these utterances become something about electrons out there. It seems to me that this is perfectly reasonable picture, but Devitt cannot take this maneuver. Because of maxim 3, we cannot introduce correspondence theory of truth before we settle the realism issue, and this ontic commitment issue is at the middle of the defense of realism. So we should settle the matter without semantics. Maybe I take maxim 3 too strictly. After the maxim 3, Devitt adds a qualification: "(This maxim is oversimplified because realism, though rarely metaphysical, is a little bit epistemic and semantic: the world must be independent of our knowledge of it and of our capacity to refer to it. So at least that much epistemology and semantics must be settled to settle realism.)" (RT, 4; emphasis original). But admitting this much of semantics does not seem to help very much. These limited epistemology and semantics may help us to say people's commitments are about something out there, but what we want is not just 'something out there,' but specific objects, namely electrons for 'electrons,' quarks for 'quarks.' To see the point, let us take Putnam's twin earth example (1975). In this imaginary example the liquid which exactly looks like water on the twin earth has actually a totally different chemical structure, XYZ. Now, here is a some arbitrariness about the correspondence rule. We can think of a correspondence rule which says our word 'water' refers to both H2O and XYZ. Another possible correspondence rule is that our word 'water' refers only to H2O. Without such correspondence rules, we fall into underdetermination about the object of the word, and therefore about the object of our ontic commitment.
Quine's famous argument for ontic commitment (1961) might help us. Quine maintains that if we use the word "exist," or, in logical formulas, existential quantification, we can commit ourselves to some ontological claim (this is also Devitt's own answer; see RT, 112). But here is a natural question: what is so magical about the word "exist" that it can somewhat connect us to mind independent reality? First of all, mere usage of the word cannot assure the ontic commitment. For example, suppose there is a monkey typing a keyboard randomly, and (after almost infinitely long time) she create a sequence of letters "electrons exist." Does this mean that the monkey commits the existence of electrons? The answer should be no. She do not know what she types. Maybe the monkey continues to type, and (again after almost infinitely long time) she manages to create the sequence that reads "Oh, of course, when I type 'electrons exist,' I mean that I commit to the existence of electrons independent of us!" This does not help much, as far as we assume that it is a result of random typing. Then, what is the difference of our utterance of similar sentences and the random typing? Obviously, when we say "electrons exist," there is some inner state corresponding to the utterance, and this inner state is the crucial difference. This seems to mean we can commit something independent of the actual linguistic expression. Maybe what Quine claims is this: we commit the existence of X if we have some inner state which can be expressed in the form " X exists." But then we have no clue what is this inner state. We may be able to proceed in this direction a little more, but this path seems hopelessly vague.
Fine seems to admit that something like "a desk-thumping, foot-stamping shout of 'Reality'" (Fine 1986a, 129) makes some difference. But what the word "real" means? Devitt's reply is that to say that something is real is to say that it exists (RT, 129), and he cites Smart (1963) for those who still have trouble with the word. Smart's answer is that when we say "electrons are not real," we mean that the concept of electron (not the electrons themselves) is defective in the similar sense that an artificial diamond is defective (in such a case, we say "this is not a real diamond") (Smart 1963, 35). In the case of concepts, the defect is that it "does not apply to anything" (Smart 1963, 36). So if we say "electrons are not real," we mean that the concept of electron does not apply to anything. Now the question is that if this clarification of the meaning of "real" help Devitt's enterprise. Devitt's own answer does not help because we are also questioning the word 'exist.' Nor does Smart's answer, because apparently we need to establish some kind of correspondence rule between concepts and objects before we can use this notion of "real" (otherwise the criterion 'to apply to something' is totally nonsense).
Another possibility is appeal to independence. Devitt says: "What realists believe is that we can judge whether theories are true of reality, the nature of which does not depend on any theories or concepts" (RT, 232, emphasis original). O.K. maybe we should add this belief to the list of attitudes we mentioned in the previous section. But it is not easy to translate this 'independence' as an attitude into the independence of the object itself. Of course this distinction does not make sense from the first person's point of view, but we can recognize the difficulty as a third person.
I think I argued enough to express my puzzlement, but finally, this puzzlement is reinforced by considering the possibility that our current theories are totally wrong (the possibility which Devitt seems to admit; see, for example, RT, 19-20). Maybe there is no such things like electrons out there. Then what are the objects of our commitment to 'electrons'?
4.2.3. Assessment of two positions
If my argument in the previous sections are sound, it is hard to make sense of the difference without correspondence theory of truth. There are two ways to interpret the result. First is that the difference between Devitt and Fine is a matter of the way of speech. They may talk about the same thing in different manner. But this interpretation may not satisfy Devitt, because the above argument has strong non-realistic implication when looking at from third person's point of view. However, to overcome, or at least to diminish that implication, there are other maneuvers Devitt can use. First Devitt can still appeal to abduction to get Realism. Another is his argument against underdetermination. Next two sections consider these possibilities in turn.
Even if we start from NOA, if we are allowed to use abduction, it is easy to arrive at Realism. But it seems to me that there are some troubles.
Hacking (1983) offers a strong case against abduction (52-57). He distinguishes three strategies to defend abduction. First strategy is "simple inference" argument, namely the strategy which says that without the reality of physical object the persistence of phenomena is an absolute miracle. But, Hacking replies, the reality of the object like photons is no part of the explanation. For example, when we explain how television works (this explanation includes photoelectronic effect), adding the remark "And photons are real" does not add any information to the explanation. Second strategy is "cosmic accidents" argument. In the course of development of science, often diverse phenomena have been connected with each other. For example, Avogadro number has been calculated from many different unrelated sources, and always shows the same value. Without assuming that the molecules really exist, this becomes a cosmic accident. Hacking dismisses this argument also, because for antirealists this shows only that the theories used to calculate Avogadro number are remarkably empirically adequate. The third strategy is an argument from "success of science", and Hacking cites several current discussions against this idea (because Devitt does not take this strategy, I do not discuss this option any more).
Despite these arguments, Hacking's own defense of the existence of microscopic phenomena clearly uses abduction, even though he try to justify his own version of abduction (201-205). Devitt sees here the warrant to use this version of abduction (RT, 112-113), but as Reiner and Pierson (1995) point out, this just means that Hacking's own strategy fails by his own argument. To see the strength of the argument, let us consider Devitt's reply to the first point. Hacking says that the reality of the photon plays no role in the explanation. According to Devitt, this is "plainly false" because the explanation quantifies over photons (RT, 112). Because of this, if the explanation is taken literally and right, there should be photons; If the explanation is not taken literally, this means that we have no causal story, and, therefore, it is no explanation at all. This Devitt's reply applies to Fine's argument against abduction with small modifications. It is true that we can replace the word 'truth' in a realist explanation with 'instrumentally reliable,' but what we want to explain is why the theory is so instrumentally reliable. Without real causal relation behind it, the success of the theory becomes unintelligible.
This Devitt's reply again depends on his Quinean ontic commitment argument. Maybe it is true we cannot be satisfied with the explanation without saying "and electrons exist" or "and the theory is true" or something like that. But the mere usage of quantification does not mean that the quantification is of the sort Realists want. It can be just a part of the core position.
I think another serious problem with abduction is that it has never formulated as a formal methodology. The problem is the notion of "good" explanation. If this is a matter of a subjective judgment, it cannot be a scientific methodology. Without solving this problem, the status of abduction seems to be much more like dialectics as a system of logic. Of course formality does not assure any validity of the system, but at least it is a prerequisite to be discussed and examined as a serious inference rule.
Another line of argument Devitt might use is his argument against underdetermination. If this argument is valid and there is a unique ontology we all can commit, the non-realistic implication of above argument is largely diminished.
The baseline of Devitt's argument against underdetermination is, as we saw above, that for any pair of theories T and T', we will be able to a set of auxiliary hypotheses to distinguish the theories empirically. Therefore he is appealing to the future solution of the underdetermination. I think that this is an unwarranted move. Please remember that the realism Devitt defends is 'realism (now)', namely realism on the objects posited by current theories. Therefore, if our current scientific theories have serious underdeterminations in their ontologies, this is enough to undermine realism (now). Any future solution of the underdetermination cannot benefit realism (now), by definition (if we exploit scientific knowledge at some future time t, this is realism(t), not realism(now)). So the question is if our current theories have such serious underdeterminations.
Devitt himself points out that it is easy to make a pair of empirically equivalent theories (RT, 132 n5). His example is between theory T which says that S and another theory which says the observable world is as if S. He dismiss this kind of underdetermination because "the latter, 'parasitic' theory does not offer an account of the unobservable world" (ibid.). It seems to me that his argument misses the point. The 'parasitic' theory is compatible with many different kinds of ontologies, including the one which says that there is nothing behind the observable world[5] . Of course this is a version of 'Cartesian scepticism' that Devitt dismissed earlier, But as I argued above, this dismissal is not warranted.
This abstract consideration can be supported by some real cases. First case is in quantum mechanics. The dominant view in the quantum mechanics is so called "Copenhagen interpretation." This interpretation is acausal, indeterministic, nonrealistic. But recently, an alternative interpretaion, "Bohmian mechanics," is gaining supporters (e.g. Cushing 1992, Bub 1994; see also Fine 1996, 194-201). Bohmian mechanics is a causal, deterministic, realistic interpretation of quantum world, and totally compatible with wave function. This means that these two interpretations are totally equivalent in their empirical predictions. Another case is general theory of relativity. If we want to understand the spacetime structure in the theory realistically, we fall into underdetermination because the theory is compatible with many different kinds of spacetime structure (Norton 1992, 227-230). In each case, the different interpretations are ontologically incompatible, but empirically equivalent under current scientific theories (equivalent in the strong sense Devitt argues). Of course future developments of science may solve these underdeterminations, but they cannot reduce the trouble of realism (now).
With these reasons, I do not think Devitt can diminish the non-realistic implication of the above argument in this way.
In this paper, I tried to make sense of Fine's NOA as opposed to realism by introducing third person's point of view. The result of the analysis shows that Fine's non-realistic interpretation of the core position has some point. It also shows that without correspondence theory of truth it is hard to avoid the non-realistic interpretation.
But this does not directly mean that we should accept NOA. Maybe it is true that the core position is non-realistic, but why we should stay there? Fine's own argument is too weak for "strong NOA" (Kukla 1994, 972), namely believing in no more than the core position upon which realists and antirealists agree. But here is one way to make sense of strong NOA. I proposed a revised version of the sceptical problematic. It says that we should choose the most certain alternative among viable ones. Now, I argued for the viability of NOA in section 4.2.1. And because NOA is a weaker position than any other realist or antirealist alternatives, we can admit a larger extent of certainty on NOA (as Devitt admits, a weaker position is always easier to defend; RT, 109). I think this combination (NOA and revised version of the sceptical problematic) provides a good case against realism.
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