Abstract

In this chapter, I outline the essentials of Bayesianism and ask whether it contributes to a satisfying account of warrant. From the perspective of my overall project in Warrant: The Current Debate, Bayesianism can be seen as essentially suggesting conditions for a rational or reasonable set of partial beliefs, where a partial belief of an agent S is any belief that S accepts to some degree or another, no matter how small. Although Bayesians tend to speak not of warrant but of rationality, I consider in this chapter the relationship between Bayesianism and warrant. I conclude that the conditions for rationality proposed by Bayesians are neither severally necessary nor jointly sufficient conditions for warrant. Taken as a theory of warrant, Bayesianism is incomplete in that it says nothing about the sort of relation between belief and experience required for warrant, and it provides no account of evidence or evidential support.