Juan José Linz (24 December 1926 – 1 October 2013) was a Spanish sociologist and political scientist. He was Sterling Professor Emeritus of Political Science at Yale University and an honorary member of the Scientific Council at the Juan March Institute. He is best known for his theories on totalitarian and authoritarian systems of government.

Linz was born in Bonn, Germany. In addition to his work on systems of government, he did extensive research on the breakdowns of democracy and the transition back to a democratic regime. He is the author of many works on the subject, including Problems of Democratic Transition and Consolidation: Southern Europe, South America, and Post-Communist Europe (Johns Hopkins University Press, 1996, co-authored with Alfred Stepan), his seminal work Totalitarian and Authoritarian Regimes (Rienner, 2000) and his influential essay 'The Perils of Presidentialism'.

Alfred Stepan is Wallace Sayre Professor of Government, the founding Director of the Center for the Study of Democracy, Toleration, and Religion (CDTR), and the Co-Director of the Institute for Religion, Culture, and Public Life (IRCPL). In 2012 he was the recipient of the Karl Deutsch Award of the International Political Science Association. The last three recipients of this award were Juan J. Linz (2003), Charles Tilly (2006), and Giovanni Sartori (2009).

Previously, Stepan was the founding Rector and President of Central European University in Budapest, Prague, and Warsaw, the former Director of the Concilium on International and Area Studies at Yale University, and Dean of the School of International Affairs at Columbia University. Stepan was also Gladstone Professor of Government at the University of Oxford and a Fellow Of All Souls College, Oxford.

Stepan's teaching and research interests include comparative politics, theories of democratic transitions, federalism, and the world's religious systems and democracy. In recent years, Stepan has conducted field research in Indonesia, Sri Lanka, Burma, Egypt, Tunisia, India, Brazil, Israel, and Palestine, among other countries. Stepan’s publications in the last three years include Crafting State Nations: India and Other Multinational Democracies, with Juan J. Linz and Yogendra Yadav; “Comparative Perspectives on Inequality and the Quality of Democracy in the United States” with Juan J. Linz in Perspectives on Politics (December 2011); “Tunisia’s Transition and the Twin Tolerations” in Journal of Democracy (April 2012); ““Rituals of Respect: Sufis and Secularists in Senegal in Comparative Perspective” in Comparative Politics (July 2012) “ Democratization Theory and the ‘Arab Spring’”, Journal of Democracy ( April 2013), (with Linz), “Democratic Parliamentary Monarchies, ” Journal of Democracy ( April 2014), ( with Linz and Minoves),and the co-editorship of Democracy& Islam in Indonesia (with Mirjam Künkler), Boundaries of Toleration ( with Charles Taylor), and Democracy, Islam and Secularism: Turkey in Comparative Perspective ( with Ahmet Kuru).

Some of his other books include Arguing Comparative Politics (Oxford 2001);Problems of Democratic Transition and Consolidation: Southern Europe, South America, and Post-Communist Europe, with J. J. Linz (Johns Hopkins 1996);Rethinking Military Politics: Brazil and the Southern Cone (Princeton 1988); The Breakdown of Democratic Regimes, edited with Juan J. Linz (Johns Hopkins 1978); The State and Society: Peru in Comparative Perspective(Princeton 1978); and The Military in Politics: Changing Patterns in Brazil(Princeton 1971).

The fate of democratic governments throughout the world is a topic of growing concern. The crises of modern history, from the Machtergreifung by Hitler through the downfall of democracies. In a systematic review of the political experiences of Latin American and European democratic nations, these original, thought-provoking books propose a significant new comparative framework for understanding the dynamics of political change and the conditions necessary for democratic stability.