Abstract

In ”Decision Theory and Epistemology,” Mark Kaplan finds it characteristic of orthodox Bayesians to hold that for each person and each hypothesis she comprehends, there is a precise degree of confidence that person has in the truth of that proposition, and no person can be counted as rational unless the degree of confidence assignment she thus harbors satisfies the axioms of the probability calculus. Kaplan's purpose is twofold. First, he aims to show that, as powerful as many criticisms are against orthodox Bayesianism, there is a credible kind of Bayesianism. Without appeal to idealization or false precision, it offers a substantive account of how the probability calculus constrains the opinions of actual persons and of how this account impinges on traditional epistemological concerns. Second, he aims to show how this Bayesianism finds a foundation in considerations concerning rational preference.