What are the rights and duties of citizens? Who should rule? What is justice? How far should the authority of government extend? These are among the perennial questions of political theory. This innovative textbook facilitates a comprehensive and systematic understanding of these and other questions by describing the alternative answers provided by the major ideologies of the 19th and 20th centuries, and by a wide variety of contemporary radical and extremist perspectives. The book demonstrates that adherents to these various outlooks can come to greater agreement about these questions than is often recognized. Ideal as text for first courses in both political theory and political ideologies, students of the book gain both a deep appreciation of the diversity of political thought and of the ideas that are central to the governance of pluralist democracies.