In this classic work, noted political sociologist Juan Linz provides an unparalleled study of the nature of nondemocratic regimes. Linz's seminal analysis develops the fundamental distinction between totalitarian and authoritarian systems. It also presents a pathbreaking discussion of the personalistic, lawless, nonideological type of authoritarian rule that he calls (following Weber) the "sultanistic regime." The core of the book (including a 40-page bibliography) was published in 1975 as a chapter in the Handbook of Political Science, long out of print. The author has chosen not to change the original text for this new edition, but instead has added an extensive introduction reflecting on some of the contributions to the literature and the changes that have taken place in world politics and in the nature of regimes since the 1970s.