Why do the conventions that enable society to cohere survive, even when it is not in everyone's interests to obey them? The book is about how the rules and institutions which are the basis of cooperation in society can be systematically explained. The social sciences which have concerned themselves with this question have frequently come up with opposite explanations, neither of which seem adequate. Economics, with its emphasis on individual choice seems unable to account for individuals following rules when it is not in their interest to do so. Sociology which can explain such rule following behaviour, struggles to account for purposeful individual action. In the place of such a stark opposition, Viktor J. Vanberg offers an analysis which cuts across traditional disciplinary boundaries between such fields as economics, law, moral philosophy, sociology and political science. Addressing such issues as the relationship between self-interest be morality and between evolution and design, his range of reference is equally wide and Vanberg analyses the contributions of Rawls, Axelrod, Gauthier and Coleman, amongst others. Particular attention is given to a comparison of Hayek's evolutionary liberalism and Buchanan's contractarian liberalism. Taken together the various parts of the volume represent a coherent theoretical argument about why institutions cohere, and why they change.