Abstract

In this paper, I argue that a realist account of the modality of moral supervenience is superior to a non-cognitivist account. According to the recommended realist account, moral supervenience amounts to strong supervenience where the outer ‘necessary’ is conceptual and the inner metaphysical. It is argued that non-cognitivism faces a critical choice between weak and strong supervenience where both options are implausible on this view. However, non-cognitivism seems to have an important advantage: It can explain why the outer ‘necessary’ is conceptual by reference to the function of moral language to influence behaviour. In the main part of the paper, I argue that realism is able to explain why ‘necessary’ in moral supervenience needs to be understood in the recommended manner by reference to the connection between moral properties and moral reasons. Moreover, I argue that the realist account has other attractive features. In contrast to non-cognitivism, it can unify the normative sphere by being generalizable to other normative notions. In addition, it can be part of an explanation of why moral language can have the function to influence behaviour.