Alan Millar examines our understanding of why people think and act as they do. His key theme is that normative considerations form an indispensable part of the explanatory framework which we use to understand each other. Millar offers illuminating discussions of reasons for belief and reasons for action, the explanation of beliefs and actions in terms of the subject's reasons, the idea that simulation has a key role in understanding people, and the limits of explanation in terms of propositional attitudes.