Open question argument

The open question argument is the heart of G.E. Moore’s case against ethical naturalism. Ethical naturalism is the view that goodness, rightness, etc. are natural properties; roughly, the sorts of properties that can be investigated by the natural sciences. Moore claims that, for any candidate naturalistic account of an ethical term according to which ‘good’ had the same meaning as some naturalistic term A, we might without confusion ask: ‘I see that this act is A, but is it good?’ Moore claimed that the existence of such open questions shows that ethical naturalism is mistaken. In the century since its introduction, the open question argument has faced a battery of objections. Despite these challenges, some contemporary philosophers claim that the core of Moore’s argument can be salvaged. The most influential defences link Moore’s argument to the difficulty that naturalistic ethical realists face in explaining the practical role of ethical concepts in deliberation.