Vague beliefs and reasoning

This paper considers the vagueness of belief itself as a category of mental state (rather than beliefs with vague contents), arguing that such vague beliefs are pervasive and strikingly diverse as well as important, both philosophically and to our mental lives. It begins by considering some fuzzy doxastic boundaries, and the borderline cases that they generate, as well as some of the reasons this vagueness is significant. It then explores an approach to vague beliefs which shows, I argue, that recognising vague beliefs can play a key role in understanding how we ought to reason.