Abstract

What is the nature of moral judgments? This question can be asked in a more specific way: When one sincerely utters a moral judgment, what does one express? A belief the content of which represents moral facts or properties, and is truth-apt, or a non-cognitive attitude the content of which does not represent moral facts or properties, and is not truth-apt? If moral judgments assert moral facts or properties, what are moral facts or properties? If moral judgments express beliefs, how can they be motivational? ;Philosophers give different answers to the above questions. Expressivism and descriptivism are two main views about the nature of moral judgments. This dissertation addresses not only the debate between expressivism and descriptivism, but also the debate between naturalism and non-naturalism about moral properties and the epistemological source of moral judgments, and the debate between rationalism and anti-rationalism about the practical source of moral judgments. ;One of main objections to descriptivism is that expressivism can do better in explaining the metaphysics of moral features, say why it is a conceptual truth that moral properties supervene on natural properties. Another main objection to descriptivism, is that expressivism better explains the practical source of moral judgments. According to expressivism, moral judgments express some motivational non-cognitive attitudes, say desires. There are two approaches to defending descriptivism: the naturalistic and the non-naturalistic. ;This dissertation develops a non-naturalistic realist, cognitivist, and rationalist view of the nature of moral properties and moral judgments. My overall point is that the expressivist attacks on descriptivism are unsuccessful. A realist non-naturalism can explain the ontological data, e.g. supervenience, the epistemological data, e.g. non-inferential justification, and the data of moral psychology, especially the motivational power of moral judgments. My conclusion is that when one sincerely utters a true moral judgment, one expresses a belief the content of which represents normative facts.