The author argues the relevance of philosophical and political theory for the interpretation of law, and especially for constitutional interpretation. He surveys all of the major contemporary theories of constitutional interpretation, and concludes that 'interpretivism', the view that interpretation should concern itself only with the text of the American Constitution and the intentions of its framers, is invalid. He presents both historical and theoretical arguments in support of a contractarian theory of interpretation - a theory that affirms the moral sovereignty of the people, and maintains that toleration, or respect for conscience and individual freedom, is the central constitutional ideal. The book goes on to examine some of the implications of this theory through important issues in constitutional law: freedom of religion, speech, and privacy.