Philosophy
The Is-Ought Problem in Ethical Naturalism
Quick fact
David Hume first identified the is-ought problem in his 1739 book A Treatise of Human Nature, calling it a 'trivial remark' that would subvert 'all the vulgar systems of morality'.
Why this is interesting
You've likely heard that you 'can't get an ought from an is.' But what if morality is just a fact about the world? That's the core tension in ethical naturalism.
Read the full explanation
Understanding The Is-Ought Problem in Ethical Naturalism
Ethical naturalism is the view that moral properties—like 'goodness' or 'rightness'—are natural properties that exist in the world, such as happiness, well-being, or evolutionary fitness. If that's true, then moral statements ('You ought to be kind') should be provable from factual statements ('Kindness increases well-being'). But David Hume pointed out a logical gap: factual premises, no matter how true, never force a moral conclusion. This is the is-ought problem. For example, describing that a society punishes thieves doesn't logically demand that you ought not to steal. Ethical naturalists try to close this gap by defining 'good' in natural terms and then showing that we naturally pursue what is good. However, critics argue that they still sneak in an 'ought' somewhere—often by assuming that natural facts already carry normative weight.
A deeper explanation
The is-ought problem challenges ethical naturalism at its core. To derive an 'ought' from an 'is', you need a bridge principle—a premise that connects description to prescription. Some naturalists, like Aristotle, claim that human nature has a telos (purpose), so facts about what fulfills that purpose generate obligations. Others, like Cornell realists, argue that moral properties supervene on natural ones without being reducible; the gap is epistemological (we don't know how to infer them logically), but not metaphysical. Still others, like neo-Humeans, deny that morality requires categorical 'oughts'—instead, it's about hypothetical imperatives based on desires. The debate matters because if ethical naturalism cannot solve the is-ought problem, it risks collapsing into non-cognitivism (moral statements are just emotions) or non-naturalism (moral facts are real but not natural). Understanding this tension helps evaluate every moral theory that tries to ground ethics in science, evolution, or human biology.