Abstract

This essay proposes and defends a descriptive definition of morality. Under this definition, a moral system is a system of rules, psychological states, and modes of character development that performs the function of enabling mutually beneficial social cooperation. I shall argue that the methodologies employed by two prominent moral psychologists to establish a descriptive definition of morality only serve to track patterns in people’s uses of moral terms. However, these methods at best reveal a nominal definition of morality, since moral appraisers may be ignorant about the referents of their moral terms. I propose a real definition of morality that characterizes moral systems as a natural kind—more precisely, a copied kind. I explain what it takes for a moral system to satisfy this definition, and I identify the sorts of evidence needed to distinguish moral systems from value systems of other kinds.