Relativism is not just an academically contested concept. It is an idea that arouses passions, especially among those who see it as the quintessence of everything that has gone wrong with modernity and its intellectual offspring, postmodernism. Relativism, to its antagonists, is the logical terminus of the erosion by an untrammeled, freewheeling intellect of the very possibility of securely grounding our knowledge, beliefs, intuitions, and judgments about what is right and wrong—both factually and morally. One such antagonist is Pope Benedict XVI. “Relativism,” he has said, in castigation of our times, is “the only attitude acceptable to today's standards,” a “dictatorship [that] does not recognize anything as definitive, and has as its highest value one's own ego and one's own desires” ( The Guardian , 19–20 April 2005). The papal critique identifies relativism with hedonism and libertinism, seeing in it a worldview whose highest value is gratification. Such a worldview ...