This book explores the historical and contemporary relationships of Protestant Puritanism to political and social authoritarianism. It focuses on Puritanism’s original, subsequent and modern influences on and legacies in political democracy and civil society within historically Puritan Western societies, with emphasis on Great Britain and particularly America, from the 17th to the 21th century. The Protestant Ethic and the Spirit of Authoritarianism: Puritanism, Democracy and Society’s importance and novelty lie in its original theoretical argument and empirical demonstration that Puritanism constitutes or reproduces political-social authoritarianism rather than liberal-secular political democracy and free civil society, contrary to the conventional wisdom in Puritan societies, especially America. The book’s methodological approach is thoroughly interdisciplinary by integrating methods, theories and data in sociology with those in other social sciences such as political science, history and economics. In addition, the book uses a comparative-historical method through comparisons of Western (and other) societies at various points of history in terms of the impact of Puritanism on authoritarianism.