Controversies in politics arise from many sources, but the conflicts that endure for generations or centuries show a remarkably consistent pattern. This revised edition of a classic analyzes the centuries-long debates about the nature of reason, justice, equality, and power. It distinguishes between those with the "constrained" vision, which sees human nature as enduring and self-centered, and the "unconstrained" vision, in which human nature is malleable and perfectible. A Conflict of Visions offers a compelling case that these opposing visions are behind the ethical and ideological disputes of yesterday and today.