Belief comes in degrees

Chapter 1 establishes Bayesianism's foundational concepts, arguing that degrees of belief—not just binary belief/disbelief—are central to epistemology. Easwaran adopts a functionalist, pragmatist approach: doxastic states are defined by their roles (pragmatic or alethic) rather than intrinsic nature. He broadens the scope beyond humans to include “the five A's”—Animals, Aliens, Artificial Intelligences, Associations (groups), and Angels—any entities with states governing action or representing truth. The chapter introduces propositions as sets of doxastic possibilities (using impossible worlds frameworks to handle logical non-omniscience), and degrees of belief as attitudes ordered by comparative confidence. Key discussions address the relationship between full belief and degrees of belief (examining eliminativism, the Lockean thesis, and various reductionist accounts), methodological approaches to conceptual analysis (contrasting analytic and pragmatic methods), and the normative rather than merely descriptive character of the project.