This book analyses the political legitimacy of the European Union, taking democratic citizenship seriously. Developing a distinctive normative theory of political association, it evaluates the project of European integration in terms of democratic values. It argues that the goods of democratic citizenship have been advanced by European integration in many respects, including environmental policy. In other respects, including social policy, democratic citizenship is best advanced by keeping primary political authority at the level of the nation-state. Weale develops these arguments through an original interplay of political science and political theory. The contents combine original normative political theory, drawing on the concept of practical reason, with applications to the fields of social policy, environmental policy, security policy and enlargement. The book is primarily an original work of political theory, but it will be of interest to all those concerned about the future of the European Union. It is written in a style that makes it accessible to students on advanced courses as well as specialists.