Epistemology is the philosophical theory of knowledge--what knowledge is and how we come to possess it. It has been the traditional concern of epistemology to say, in some general way, by what principles the opinions and beliefs of a rational person ought to be constrained. Epistemology has drawn for these constraining principles from reflections on metaphysical matters, investigations of the context of justification of a theory, observations concerning the actual practice of inquiry or investigations into cognitive processes exemplified by human inquirers. In this research project, Dr. Kaplan is investigating how Bayesian decision theory, a theory that says something general and informative about when it is rational to prefer one gamble to another, is essential for a theory of epistemology that says something general and informative about when it is rational to invest more confidence in one hypothesis than another. Dr. Kaplan aims to explain why the central result of Bayesian decision theory constitutes a genuine and important contribution to epistemology. To do this, he is presenting a new argument for the claim that rational confidence is a probabilistic affair. Given this argument, the very intelligibility of the talk about belief, acceptance and knowledge becomes doubtful. Dr. Kaplan offers an intelligible reconstrual of acceptance and belief that enables a Bayesian epistemology to resolve difficulties for theories of rational belief and acceptance that are intractable outside of a Bayesian framework.
