Democracy is not naturally plausible. Why turn such important matters over to masses of people who have no expertise? Many theories of democracy answer by appealing to the intrinsic value of democratic procedure, leaving aside whether it makes good decisions. In Democratic Authority, David Estlund offers a groundbreaking alternative based on the idea that democratic authority and legitimacy must depend partly on democracy's tendency to make good decisions.

Just as with verdicts in jury trials, Estlund argues, the authority and legitimacy of a political decision does not...