According to a recent scholar, political ideologies in this century have replaced religion as the focus of both human liberation and human fanaticism. These ideologies, for example, communism, democracy and nationalism, whose names are well recognized but whose contents are not well known, form the focus of this study. Since the original edition in 1969, this study has found a steady audience among those courses on political thought and comparative politics that require a readable yet concise treatment of political ideologies. This book presents the essential features of certain belief systems in the world today in a way that can be readily understood. To the extent possible, I have tried to present the ideologies as they are understood by their believers together with criticisms made by their opponents.