Metaethical realists disagree about the nature of normative properties. Naturalists think that they are ordinary natural properties: causally efficacious, a posteriori knowable, and usable in the best explanations of natural and social sciences. Non-naturalist realists, in contrast, argue that they are sui generis: causally inert, a priori knowable and not a part of the subject matter of sciences. It has been assumed so far that naturalists can explain causally how the normative predicates manage to refer to normative properties, whereas non-naturalists are unable to provide equally satisfactory metasemantic explanations. This article first describes how the previous non-naturalist accounts of reference fail to tell us how the normative pre...