ABSTRACT
The philosophical movement of naturalism is normally divided into two strands. One is a methodological one: roughly, that philosophy (or some area of philosophy) should proceed using the methods of the sciences, particularly the natural sciences. The other is a metaphysical one: roughly, that the theory of the world that results from our philosophical inquiries should match, or at least not conflict with, what the sciences tell us there is. This chapter focuses on methodological naturalism as an approach to metaethics. There are many naturalistic projects, small and large, that are being carried out in metaethics. Naturalism in ethics can seem like a radical doctrine, especially against the background of insistence by people like Moore and Wittgenstein that ethics cannot be science. Debates in moral philosophy frequently feature appeals to "intuition", and some theories of the source of moral intuitions make using intuitions radically different from engaging in scientific method.
