Constitutionalism & Political Theory:
* Constitutional Government and Democracy: (1937) This book is considered his magnum opus and a seminal work in the field of constitutionalism. It examines the historical development of constitutional government and its relationship to democracy.
* The Philosophy of Law in Historical Perspective: (1958) This work explores the history of legal philosophy, examining the ideas of major thinkers from Plato to contemporary philosophers.
* Man and His Government: (1963) This book explores the relationship between the individual and the state, examining concepts of liberty, equality, and justice.
Comparative Government:
* Totalitarianism: (1954, co-authored with Zbigniew Brzezinski) This influential book provides a comprehensive analysis of totalitarian regimes, focusing on their characteristics, origins, and potential dangers.
* The Pathology of Politics: (1972) This work examines the various pathologies that can affect political systems, including corruption, tyranny, and political instability.
Other Notable Works:
* The Age of the Industrial Revolution: (1955) A study of the social and economic transformations of the 18th and 19th centuries.
* The Soviet Union: (1958) An analysis of the political and economic systems of the Soviet Union.
* The Public Interest: (1962) An exploration of the role of public interest in democratic societies.
* The United States: (1968) A comparative study of the American political system.
* Foreign Affairs: (1974) A collection of Friedrich's essays on foreign policy and international relations.
Friedrich's work is characterized by its rigorous scholarship, wide-ranging knowledge, and insightful analyses of political systems and their complexities. He remains a significant figure in political science, and his writings continue to be studied and debated today.