Three grand themes characterized the twentieth century: crises on a scale that outstripped any in human history; revolutionary ideology and action that brought social and political transformations on a global scale; and new technologies breathtaking in their pace and innovation. It was a century of triumphant creativity and achievement, yet it witnessed violence and destruction of appalling, even cataclysmic, intensity. How can such contradictions be captured so that those who live in the twenty-first century may understand, and perhaps learn from, the varieties of human experience in the...