Why and how do people form groups to change their society? Analyzes reformist, revolutionary, and nationalistic struggles; their typical patterns and cycles; and the role of leaders as well as symbols, slogans, and ideologies. Concentrates on recent social movements such as civil rights, feminism, ecology, the antinuclear movement, and the New Right; asks how these differ from workers? movements. Examines reformist versus radical tendencies in political movements.