Naturalism and Evolutionary Metaethics
Whether moral facts are part of the natural world, and what evolution implies for the status of moral judgement.
Definition
Ethical naturalism is the view that moral facts and properties are natural facts and properties, accessible in principle to empirical inquiry; evolutionary metaethics studies what the evolutionary origins of moral capacities imply for the truth, justification, and metaphysics of moral claims.
Scope
This area covers the relation between morality and the natural sciences. Ethical naturalism holds that moral properties are natural properties, identifiable with or reducible to features studied by the natural and social sciences. It surveys the synthetic (Cornell) naturalist program, the classic obstacles to naturalism — Moore's open-question argument and Hume's is-ought gap — and the evolutionary debunking arguments that draw on the natural history of morality to challenge moral realism.
Sub-topics
Core questions
- Are moral properties identical to or reducible to natural properties?
- Does the open-question argument refute ethical naturalism?
- Can an 'ought' be derived from an 'is'?
- Does the evolutionary origin of moral beliefs undermine moral realism?
Key concepts
- ethical naturalism
- open-question argument
- is-ought gap
- synthetic identity
- Darwinian dilemma
Key theories
- Cornell (synthetic) naturalism
- Moral properties are natural properties identified a posteriori, like natural kinds in science, so moral terms can refer to natural features without being synonymous with natural descriptions.
- Open-question anti-naturalism
- Moore argued that for any natural property proposed as identical to goodness, it remains an open question whether things with that property are good, suggesting goodness is non-natural.
- Evolutionary debunking
- Street's Darwinian dilemma argues that since our evaluative attitudes are shaped by natural selection rather than by independent moral truths, realists cannot explain how those attitudes track such truths.
History
Naturalism faced two classic challenges early: Hume's observation about the is-ought transition (1739) and Moore's open-question argument (1903), which together dominated the topic for decades. The 1980s saw a naturalist revival in the Cornell realism of Boyd and Railton, and from 2006 Street's and Joyce's evolutionary debunking arguments reframed the debate around the genealogy of moral belief.
Debates
- Whether the open-question argument works
- Synthetic naturalists reply that the openness of the question reflects only difference in meaning, not difference in property, so moral and natural properties can be identical a posteriori despite the open question.
- The force of debunking arguments
- Street argues evolutionary origins leave realists unable to explain the reliability of moral belief; realists respond by positing a third-factor link or by adopting a naturalism on which selection tracked the relevant truths.
Key figures
- G. E. Moore
- Richard Boyd
- Peter Railton
- Sharon Street
- David Hume
Related topics
Seminal works
- hume1739
- moore1903
- railton1986
- boyd1988
- street2006
Frequently asked questions
- Does ethical naturalism mean morality is just biology?
- No. Ethical naturalism claims moral properties are natural properties broadly construed, which may include social and psychological facts, not merely biological ones; it does not reduce morality to evolutionary fitness.