A Nation of Agents: The American Path to a Modern Self and Society. By James Block. Harvard University Press, 658 pp., $45.00.

Ambitious, obsessive efforts to see American history whole and anew are rare these days. Some academic historians have lamented the balkanization of the professional study of the nation's past into subspecialties of ever-refined narrowness. Yet hamstrung by postmodern suspicion of "master narratives," even they warily avoid anything that might count as a fresh, big, synthetic idea. Indeed, such wariness has come to be the mark of respectability in the guild. Sweeping stories have been left largely to nonacademics, who may do them well, but these talented amateurs are if anything even more immune to bold theoretical speculation.

What a wonder then is James Block's book, a daring master narrative and bracing theoretical exercise of the first order. It promises and delivers nothing less than a fundamental recasting of "the American path to a modern self and society."