On having no reason: dogmatism and Bayesian confirmation

Recently in epistemology a number of authors have mounted Bayesian objections to dogmatism. These objections depend on a Bayesian principle of evidential confirmation: Evidence E confirms hypothesis H just in case Pr(H|E)>Pr(H). I argue using Keynes’ and Knight’s distinction between risk and uncertainty that the Bayesian principle fails to accommodate the intuitive notion of having no reason to believe. Consider as an example an unfamiliar card game: at first, since you’re unfamiliar with the game, you assign credences based on the indifference principle. Later you learn how the game works and discover that the odds dictate you assign the very same credences. Examples like this show that that if you initially have no reason to believe H, then intuitively E can give you reason to believe H even though Pr(H|E)≤Pr(H). I show that without the principle, the objections to dogmatism fail. Epistemology concerns both the nature of epistemic justification but also the lack thereof. On many understandings of epistemic justification, justification requires reasons; epistemologists are therefore also interested in the notion of having no reason to believe that P. It is this intuitive notion that I examine in this paper. Recently in epistemology there has been a resurgence of interest in applying formal methods to epistemological problems. To evaluate these applications we need a clear understanding of the ingredient intuitive epistemic notions, like having no reason. For instance, 1 Thanks to my Claremont colleagues Peter Thielke, Paul Hurley, Alex Rajczi, Rivka Weinberg, Yuval Avnur, and Charles Young; to Peter J. Graham of UC Riverside; to Stew Cohen; and to an audience at the 2007 Southern California Philosophy Conference. Double thanks to Matt Kotzen, who read an early draft and provided excellent commentary when I presented this paper at the Pacific APA in 2008; I am also grateful to the audience at that APA session. Special thanks to Masahiro Yamada for (as always) many fruitful conversations and constructive criticism, and to Will Hancock for research assistance and valuable discussion. PAPER #6 Paper #1