Many of the judgments we express in everyday moral discourse employ concepts which rarely appear in works of ethical theory. Those engaged in constructing and defending ethical theories typically proceed on the assumption that judgments using terms like 'evil', 'saint', 'obscene' and others can be easily translated into a much sparser, and hence more easily theorized, moral vocabulary. However, a careful examination of our moral language suggests that this assumption is unwarranted and that by focusing on a small set of moral concepts ethical theories have ignored much of our moral thinking. This has a number of problematic consequences, especially for those who believe that the justification of an ethical theory derives from its ability to bring our moral beliefs into a state of reflective equilibrium. Our moral concepts also play a role in the formation of moral beliefs as instruments of moral perception. Judgments as to whether particular moral terms serve to reveal or to obscure ethically important features of the world will affect the evaluation of ethical theories, a fact that has important implications for how we conceive of the methods and tasks of moral philosophy.