Ethical Naturalism

Ethical naturalism (also called moral naturalism or naturalistic cognitivistic definism) is the meta-ethical view which claims that:

1. Ethical sentences express propositions
2. Some such propositions are true
3. Those propositions are made true by objective features of the world, independent of human opinion
4. These moral features of the world can be reduced to some set of non-moral features

This makes ethical naturalism a definist form of moral realism, which is in turn a form of cognitivism. Ethical naturalism stands in opposition to ethical non-naturalism, which denies that moral terms refer to anything other than irreducible moral properties, as well as to all forms of moral anti-realism, including ethical subjectivism (which denies that moral propositions refer to objective facts), error theory (which denies that any moral propositions are true), and non-cognitivism (which denies that moral sentences express propositions at all).

It is important to distinguish the versions of ethical naturalism which have received the most sustained philosophical interest, for example, Cornell Realism, from the position that "the way things are is always the way they ought to be"; few ethical naturalists believe such a slogan. Ethical naturalism does, however, reject the fact-value distinction: it suggests that inquiry into the natural world can increase our moral knowledge in just the same way it increases our scientific knowledge. Indeed, proponents of ethical naturalism have argued that humanity needs to invest in their science of morality – although the existence of such a science is debated.

Ethical naturalism encompasses any reduction of ethical properties, such as 'goodness', to non-ethical properties; there are many different examples of such reductions, and thus many different varieties of ethical naturalism. Hedonism, for example, is the view that goodness is ultimately just pleasure.