There is no foolproof way to distinguish true from false prophets – that is one of the challenges prophecy poses to politics. But studying these true prophets does enable us to identify many false prophets, past and present. Today, human rights activists attempt to play a role in our politics comparable to the prophets of old. They also call out the abuses of our religious and political leaders. No one should want to be ruled by a prophet; but we should want our rulers to heed true prophets. Let others build and administer new institutions and policies; let others forge agreements and create consensus. We shall always need prophets with the courage to obstruct the exercise of power, to disrupt our institutions, and to challenge the consensus. According to ancient Greek myth, swans were sacred to Apollo, the god of prophecy. Just before they die, swans were thought to sing. Socrates himself, once he was condemned to death, said that it was time for his swan song, for his moment of prophecy. Indeed, all of our prophets spoke most prophetically only after they accepted their own deaths.