Millennialists through the ages have looked forward to the apocalyptic moment that will radically transform society into heaven on earth. They have delivered withering critiques of their own civilizations and promised both the impending annihilation of the forces of evil and the advent of a perfect society. And all their promises have invariably failed. We tend, therefore, to dismiss these prophets of doom and salvation as crackpots and madmen, and not surprisingly historians of our secular era have tended to underestimate their impact on our modern world. Now, Richard Landes offers a lucid...