"The perils of uncontrolled power are perennial reminders of the virtues of a democratic society. But modern democracy requires a more realistic philosophical and religious basis, not only in order to anticipate and understand the perils to which it is exposed, but also to give it a more persuasive justification. Man's capacity for justice makes democracy possible; but man's inclination to injustice makes democracy necessary."

Reinhold Niebuhr, The Children of Light and the Children of Darkness (1945).