Sets up parameters for the book's approach — focuses on epistemic (rather than pragmatic) rationality; looks at conditions on simultaneous rational beliefs (rather than on rational changes of belief); and concentrates on global rationality—conditions for an agent's whole system of beliefs (rather than on local conditions for the rationality of particular beliefs). These choices are designed to focus the inquiry where formal logic is most likely to be useful in characterizing ideal rationality.
Keywords: change of belief, epistemic rationality, global rationality, pragmatic rationality, simultaneous beliefs,