Philosophical Studies

, Volume 139, Issue 3, pp 307–327 | Cite as

Sound intuitions on Moral Twin Earth



A number of philosophers defend naturalistic moral realism by appeal to an externalist semantics for moral predicates. The application of semantic externalism to moral predicates has been attacked by Terence Horgan and Mark Timmons in a series of papers that make use of their “Moral Twin Earth” thought experiment. In response, several defenders of naturalistic moral realism have claimed that the Moral Twin Earth thought experiment is misleading and yields distorted and inaccurate semantic intuitions. If they are right, the intuitions generated by Moral Twin Earth cannot be appealed to in arguments against externalist moral semantics. The most developed case against the Moral Twin Earth argument that follows this strategy is found in a paper by Stephen Laurence, Eric Margolis and Angus Dawson. Here I argue that their attack on the Moral Twin Earth thought experiment fails. Laurence, Margolis and Dawson have not shown that we have reason to distrust the semantic intuitions it generates


Ethical naturalism Moral realism Moral Twin Earth Terence Horgan Mark Timmons Stephen Laurence Eric Margolis Angus Dawson 


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Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  1. 1.Department of PhilosophyUniversity of MassachusettsAmherstUSA

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