Abstract

This chapter defends what is called the Humean thesis on belief: a perfectly rational agent believes a proposition just in case she has a stably high degree of belief in it. The thesis is motivated first by some considerations on the stability of belief that derive from Hume’s _Treatise_. Afterwards the thesis is made formally precise, which yields an explication of the mutual coherence between rational belief and subjective probability. Finally, the explication is justified in terms of three of its consequences: the logic of belief, the Lockean thesis on belief, and the coherence between decision-making based on rational all-or-nothing beliefs and Bayesian decision-making.