"The transmigration of souls is no fable. I would it were, but men and women are only half human." With these words, Ralph Waldo Emerson confronts a dilemma that illuminates the formation of American individualism: to evolve and become fully human requires a heightened engagement with history. Americans, Emerson argues, must realize history's chronology in themselves--because their own minds and bodies are its evolving record.

Whereas scholarship has tended to minimize the mystical underpinnings of Emerson's notion of the self, his depictions of "the metempsychosis of nature" reveal deep...