This book examines a number of different accounts developed by philosophers and political theorists to explain why political disagreement is so extensive and persistent. The author argues that moral and political questions can have correct answers, but that not every reasonable person will necessarily be satisfied with these answers. He develops a framework that gives a role to the individual's reasons for his or her beliefs, but also to psychological and sociological factors, to explain the intractability of political disputes.

Communities can be of different kinds, and exist at different levels in society. What kind of community is valuable at the level of the state and what is its significance for communities above and below that level? This book systematically explores the limits that ideals of political community place on cultural diversity within the state, and the limits that, in turn, ideals of global community place on the self-determination of political communities. It will be of interest to students of political theory, philosophy and international relations.