Abstract

Principles of rationality are invoked for several purposes: they are often deployed in explanation and prediction; they are also used to set standards for rational health for deliberating agents or to furnish blueprints for rational automata; and they are intended as guides to perplexed decision makers seeking to regulate their own attitudes and conduct. These purposes are quite different. It is far from obvious that what serves well in one capacity will do so in another. Indeed, I shall argue later on in this essay that when principles of rationality are intended for use as norms for self-criticism, they cannot also serve as laws in explanation and prediction or as blueprints for rational automata.