When we say that sharing is morally good and that murdering is wicked, what are we doing? Are we picking out existing moral values? Can our judgements be correct and incorrect? How do moral values fit into the natural world? Do moral values even exist? How do our moral judgements relate to how we are motivated to act? Metaethics is an argumentative textbook that considers these and other metaethical questions in a lively and clear manner. As well as discussing all of the main metaethical positions, a new idea - metaethical pluralism - is introduced. Chapters cover central topics in the subject, including: * Moral realism: initial thoughts * Moral realism: naturalism and reductionism * Moral error theory * Noncognitivism * Sensibility theory * Moral motivation Metaethics is aimed at upper-level undergraduates and postgraduates, but should appeal to anyone with an interest in the area.