Decision Theoretic Epistemology

Abstract

In an effort to throw new light on the nature of justification, Professor Keith Lehrer has worked out, in recent years, a theory of based on one's subjective probability assignments ([2], [3], [4] and [5]). He eschews both foundations theories and appeals to explanatory coherence, relying instead on the corrected coherence of one's beliefs and subjective probability assignments when one's only goal is to believe as many truths as one can while believing the fewest falsehoods. This highly original approach deserves careful evaluation. By epistemic justification is meant, roughly, the required, but not sufficient, for knowledge. Economic, political, and moral considerations are not germane. Lehrer has tried to specify conditions necessary and sufficient for a person to be epistemically justified in believing that something is the case. His work raises the question, can an adequate analysis of be worked out in terms of subjective probability and Bayesian Decision Theory? The attempt to answer this question requires not only that Professor Lehrer's own work be critically appraised (see [7] and [11]) but also that major alternative methods sharing the basic strategy of his program be explored. In this paper one of these alternatives is proposed.