Inductions, Red Herrings, and the Best Explanation for the Mixed Record of Science
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University at Albany, State University of New York Scholars Archive Philosophy Faculty Scholarship Philosophy 6-2010 Inductions, red herrings, and the best explanation for the mixed record of science P.D. Magnus University at Albany, State University of New York, [email protected] Follow this and additional works at: https://scholarsarchive.library.albany.edu/cas_philosophy_scholar Part of the Philosophy of Science Commons Recommended Citation Magnus, P.D., "Inductions, red herrings, and the best explanation for the mixed record of science" (2010). Philosophy Faculty Scholarship. 49. https://scholarsarchive.library.albany.edu/cas_philosophy_scholar/49 This Article is brought to you for free and open access by the Philosophy at Scholars Archive. It has been accepted for inclusion in Philosophy Faculty Scholarship by an authorized administrator of Scholars Archive. For more information, please contact [email protected]. Inductions, red herrings, and the best explanation for the mixed record of science P.D. Magnus∗ December 22, 2009 This is the author's final draft of a paper forthcoming The British Journal for the Philosophy of Science. e-mail: pmagnus(at)fecundity.com web: http://www.fecundity.com/job Abstract Kyle Stanford has recently claimed to offer a new challenge to sci- entific realism. Taking his inspiration from the familiar Pessimistic In- duction (PI), Stanford proposes a New Induction (NI). Contra Anjan Chakravartty's suggestion that the NI is a \red herring", I argue that it reveals something deep and important about science. The Problem of Unconceived Alternatives, which lies at the heart of the NI, yields a richer anti-realism than the PI. It explains why science falls short when it falls short, and so it might figure in the most coherent account of scientific practice. However, this best account will be antirealist in some respects and about some theories. It will not be a sweeping antirealism about all or most of science. Kyle Stanford [Sta01][Sta06] claims to mount a new challenge to scientific realism. Taking his inspiration from the familiar Pessimistic Induction (PI), Stanford proposes a New Induction (NI). Anjan Chakravartty [Cha08, p. 153] has recently called the NI a \red herring", arguing that it poses no new prob- lem for realism. Patrick Enfield suggests similarly that \Stanford might deny it, but. what really does the work in this argument are `historical' claims associ- ated with the pessimistic induction" [Enf08, p. 883]. I argue that this charge is unjustified. Moreover, the Problem of Unconceived Alternatives | which lies at the heart of the NI | yields a richer anti-realism than the PI. It explains why science falls short when it falls short, and so it might figure in the most coherent ∗This paper grew out of a seminar at the University at Albany, SUNY. I want to thank all the participants, especially John Milanese and Elizabeth Gray. Thanks to Anjan Chakravartty, Gregory Frost-Arnold, Kyle Stanford, and anonymous referees for feedback on earlier drafts. 1 account of scientific practice. This antirealist element in our best explanatory account of science may ultimately be galling to realists, but it won't be all wine and roses for antirealists either. In x1, I review the familiar Pessimistic Induction. In x2{x3, I discuss how best to understand Stanford's New Induction. In x4, I consider the objection that the NI is a red herring. I argue that it is not. In x5, I suggest that the challenge Stanford mounts to realism leads to a richer account of science than previous arguments like the PI. 1 The Pessimistic Induction The Pessimistic Induction (PI) relies on the history of science in an attempt to establish anti-realism in this way: PI-1 The historical record reveals that past theories which were successful typ- ically turned out to have been false. PI-2 So, our present scientific theories, although successful, will probably turn out to be false. PI-3 Therefore, we should not believe our best present theories. In the voluminous literature replying to the PI, realists have tried to block the argument in a number of ways. Several kinds of objection are worth distinguish- ing. First, even admitting that there is a pattern in the historical record, gener- alizing from the pattern might be fallacious. Various statistical considerations have been used to try and block the move from history to PI-1. Lewis [Lew01] has argued that it commits a base rate fallacy. Lange [Lan02] has argued that it commits what he calls the turnover fallacy. To be sure, generalizing from history is a tricky business. Second, realists try to block the inference from PI-1 to PI-2 by insisting that present theories are better in some respect than abandoned past theories. If this difference can be made explicit, so much the better | but even in the absence of an explicit description, a realist can still claim that there is some difference. Stanford acknowledges the possibility of this reply and accepts it arguendo [Sta06, p. 10{11], but he does not seem to give it much weight; after answering the third sort of reply (discussed below), he considers the PI estab- lished. Nevertheless, this realist reply need not be hopelessly ad hoc. One might consider this to be part of a realist package, in the sense of Boyd [Boy90]. The idea behind the package reply is this: The anti-realist may match the realist on each individual point, with each individual contention coming to a stalemate. Nevertheless, realism does better as an overall view | it provides a more coher- ent explanatory account of science. Part of the realist account is that present theories are better than past theories, and so we have some reason to believe that they are. 2 Third, realists say that the parts of the theories that got the world right were the same parts that were responsible for the theories' success. These parts have not been rejected, but instead continue as parts of present theories. Just as we still believe in the working parts of past theories, we should now believe in the working parts of our present theories. Arguments of this kind are given by Kitcher [Kit93] and Psillos [Psi99], among others. The approach admits that past theories were literally false, while insisting that they were nevertheless partly correct. Following Chang [Cha03], I'll call this approach preservative realism. Stanford calls this an appeal to \partial confirmation” and replies to it at length [Sta06, chs. 5{6]. We might be able to tell such a story retrospectively, he argues, but it should come as no surprise that the parts of the successful past theories that we now think were the core of them were the parts that we now think are true. What is judged to have been useful is what is judged to have been true, but the standards by which we judge what was efficacious are the same standards by which we judge what was true. Moreover, preservative realism only allows the realist to say after the fact which parts of a theory were doing the work. That is, the realist can only retrospectively identify which parts of a superseded theory were likely to be true and thus were worthy of belief. It is not enough for scientific realism as a general doctrine that we can, in some special instances, divide the confirmed from the unconfirmed parts of present theories. A general doctrine requires a general criterion. Stanford does not claim a priori that such a forward-looking criterion is impossible, but notes that we do not have such a criterion and do not have any prospects for finding one. If Stanford is right, then the realist cannot justify belief in our present theories | we will only be able to say at some point in the future what it is that we would now have been justified in believing today. Stanford calls this a \pyrrhic victory" for realism. They win the preservative battle at the cost of their realist souls. 2 Stanford's New Induction Stanford poses a problem which he means to be a hybrid of the PI and the problem of underdetermination. He dubs it the Problem of Unconceived Alter- natives, and he means to establish it by a New Induction (NI). In this section, I briefly summarize the NI. Scientists typically cannot address all the relevant theoretical alternatives. There are theories which never explicitly occur to them as live possibilities, but which later scientists take seriously. Yet scientists often rely on eliminative inference; that is, they rule out all but one of the possibilities and conclude that whatever remains must be right. (On the importance of eliminative inference to science, see inter alia Kitcher [Kit93, ch. 7] and Bird [Bir06].) Of course, eliminative induction is sometimes justified. It is an \old axiom," as Sherlock Holmes says, \that when all other contingencies fail, whatever re- mains, however improbable, must be the truth" [Doy05, p. 926]. To take a mystery-story example, suppose we know that one of five suspects in the se- 3 cluded manor must have committed the murder. If evidence exonerates four of them, then the fifth must be the killer. It is always logically possible to question the exhaustion premise in such a case, but there might not be any alternatives worth taking seriously in a mundane case like this. The requisite premise is contingent and known only fallibly, but we can know it in some cases. Stanford will admit as much, and he is not concerned to challenge every use of eliminative inference [Sta06, p. 29 ff.]. In scientific cases concerning distant regions or exotic features of the world, however, Stanford argues that we cannot be confident that we have considered all the possibilities.