Davidson, the author of numerous books about Africa, handles his broad subject matter with assured informality. Synthesizing anthropological and historical material about ""the solitudes of ancient Africa"" through the consolidation of kingdoms and empires to post-colonial crises, he foregoes chronological precision and marks local variation at his pleasure. He is free with concepts like ""interacting duality"" and ""kinship continuum"" yet the book is anything but abstract. Stratifications, institutional development, family structures and constitutional arrangements are described with fresh particularity. Religions are approached, as ideologies promoting social concord, rather than for mere picturesque lore or total explanations of social behavior. Davidson offers abbreviated discussions of Moslem trade and the European intrusion. Specialists may find the book glib in style and pretentious in content. Nevertheless it is suggestive, responsible, not to say readable enough to stimulate both students and dabblers to pursue Davidson's basic ""mechanisms of change"" theme.