Abstract

The epistemology of moral principles should be developed in relation to general epistemology and integrated with a plausible moral ontology. On both counts, it is important to consider the nature of moral properties and, more generally, normative properties. This paper distinguishes two kinds of normative properties, indicates how they are related to one another and to moral properties, contrasts their supervenience on natural properties with their grounding in those properties, and, in the light of the points then in view, argues for a moderately rationalist account of knowledge of moral principles. The paper also considers in detail how one might account for the a priori status of certain moral principles—a status that remains controversial and is in any case difficult to establish. The final section shows how the overall position of the paper may be consistent with moral naturalism but does not depend on it.