Moral claims not only purport to be true, they also purport to guide our choices. This book presents a new theory of normative judgment, the "standard-based theory," which offers a schematic account of the truth conditions of normative propositions of all kinds, including moral propositionsand propositions about reasons. The heart of Copp's approach to moral propositions is a theory of the circumstances under which corresponding moral standards qualify as justified, the "society-centered theory." He argues that because any society needs a social moral code in order to enable itsmembers to live together successfully, and because it would be rational for a society to choose such a code, certain moral codes, and the standards they include, are justified. According to the standard-based theory then, if certain moral standards are indeed justified, corresponding moralpropositions may be true. Copp's approach to morality and explaining normativity and the truth conditions of moral claims, raises a number of important issues in moral theory, as well as in metaphysics and the philosophy of language.