Communities are the chief source of philosophical sloppiness these days. Varying endlessly across the entire range of human experience, communities raise the specter of moral relativism that makes ethics sometimes seem a misguided and futile enterprise. Yet the language of communities and their multitude of norms, preferences, and principles present an opportunity, and challenge, to confront abiding moral problems in immeasurably richer and more novel ways. But neither the opportunities nor the challenges were always obvious. On the contrary, the origins of the Enlightenment coincide with an assault on the disharmony posed by restless and unruly communities.