THE DARWINIAN ARGUMENT IN METAETHICS

The Darwinian Argument in metaethics, as interpreted in this paper, aims to establish two theorems: (1) if our moral beliefs are effects of the mechanism of genetic or memetic natural selection, then they do not constitute knowledge; (2) if they are effects of the mechanism in question, they are not doxastically rational. The first part of the paper is devoted to the rational reconstruction of the argument thus understood. The second part analyzes the reconstructed argument and its significance from the vantage point of three major types of metaethical theories, i.e. naturalism, non-naturalism, and expressivism. It is argued that in principle naturalists and expressivists are in a position to refute the argument, but this is not true of non-naturalists.