Moses presents Morgan’s life in great detail, with facts that will surprise even those who think they know him. From his early work with the Iroquois to his defense of American capitalism to his strange posthumous career among international communists and American leftists, Moses weaves together the diverse strands that made up the rich tapestry of this singular life. He locates Morgan’s American voice within a tradition of transatlantic social theory dedicated to understanding the spirit that motivates modern societies. In showing how Morgan reflected the interplay between Christian, classical, and liberal traditions, Moses delves into the role of such concepts as “savagery,” “barbarism,” the “primitive,” “progress,” and “civilization” in nineteenth-century social theory and in the broader American culture. And he tells how even today Morgan’s influence is felt among environmentalists, anarchists, feminists, and other social visionaries.