Hurley here revives a classical idea about rationality in a modern framework, by developing analogies between the structure of personality and the structure of society in the context of contemporary work in philosophy of mind, ethics, decision theory and social choice theory. The book examines the rationality of decisions and actions, and illustrates the continuity of philosophy of mind on the one hand, and ethics and jurisprudence on the other. A major thesis of the book is that arguments drawn from the philosophy of mind may be used to undermine widely held subjectivist positions in ethics and politico-economic theory. The work is inspired by the philosophies of Wittgenstein and Davidson, but goes on to connect their arguments about interpretation with formal work in decision theory and social choice theory, and with the theory of adjudication.