The question Jon Elster addresses in this challenging book is what binds societies together and prevents them from disintegrating into chaos and war. He analyses two concepts of social order: stable, predictable patterns of behaviour, and co-operative behaviour. The book examines various aspects of collective action and bargaining from the perspective of rational-choice theory and the theory of social norms. It is a fundamental assumption of the book that social norms provide an important kind of motivation for action that is irreducible to rationality. The book represents a major statement by Elster, which will be of particular interest to political scientists, political philosophers, sociologists, and economists.