Three components of rationality

Chapter 7 distinguishes three separate rational requirements on degrees of belief, each with distinct justifications. Probabilism follows from the internal functional role of credences—whether pragmatic or alethic—and requires degrees of belief to satisfy probability axioms over the agent's own doxastic possibilities. Logical omniscience concerns which possibilities an agent recognizes, requiring rationality about the structure of possibility itself rather than credences over possibilities. Conditionalization governs diachronic updates and depends on the unity of the agent across time. The chapter explores whether this unity derives from shared interests between temporal stages, Parfitian attenuated personal identity, or Korsgaardian agency that constitutes identity through commitment. Easwaran argues these three norms cannot be reduced to a single concept of rationality, as violations of each represent fundamentally different types of irrationality with different sources and implications.