Abstract

Philosophers are drawn to the Atomic Theory like a dog to an old shoe, but my results about realism and anti-realism in Tracking Truth, and the distinctive position I have carved out on their basis, are independent of the fate of my comments about that historical case. I will defend those comments against Stanford’s objections below, but first I will explain the argument of my chapter, because its results undermine not only historically important antirealist positions, but also the approach via unconceived conceivables that Stanford’s criticisms (and his pessimistic induction) depend on. The issue is claims about equal evidential support that empiricist defenses of epistemological anti-realism, including Stanford’s, must and do appeal to. In Chapter 6 of Tracking Truth, I show that the best known probabilistic definitions of evidential support imply the anti-realist’s key equalsupport claims are either false or inconsistent with the view he wants to base on them. There are reasons to think that it is not even possible to define a probabilistic notion of support that will do the job the anti-realist needs. It follows from this, as I explain below, that the anti-realist has not defended the claim that we are in principle, or even probably, unable to confirm high-level theories – for this, I say, we must wait and see, and make our best estimates. This, and my claim that we have actually gotten beyond observables – a point made with pregnancy tests and tests for medical conditions – make room for realism. I do not endorse the kind of realist claim that says we generally have a right to believe our successful hypotheses that go beyond observables. Some successful hypotheses are better confirmed than others, and some are not at all. However, since the anti-realist’s general skeptical arguments fail, I also do not think we need such general claims in order to have a right to confidence in those particular hypotheses for which we do have good evidence. I call my approach to the epistemological realism-anti-realism debate “evidential.” The nub of the issue between the two camps has always been whether we have a right to believe our scientific theories – in some sense that includes at least some of their claims about unobservable matters – on the basis of our evidence.1 Answers to this question depend on what our evidence actually is, and on the definition or criteria for evidential support..