Moral Realities engages the classical moral philosophies of Hume, Mandeville and Nietzsche, and tackles the powerful arguments of the contemporary moral relativists. Platts uses an existing critique of philosophical notions of desire and value to present a descriptive metaphysics of morals--clarifying both what morality is and what it is not. He also employs a classification of desire that articulates a general theory of value and valuing which is distinguished by a cognitive approach given to certain kinds of moral valuing. The possibility of applying this approach to moral valuings is defended against the persuasive criticisms of both the Humean subjectivist and the contemporary moral relativist.