Abstract

Jesse Prinz develops a naturalistic metaethical theory with which he purports to sidestep ‘Hume's law’ by demonstrating how, on his theory, in describing what our moral beliefs commit us to we can determine what our moral obligations are. I aim to show that Prinz does not deliver on his prescriptive promise – he does not bridge the is–ought gap in any meaningful way. Given that Prinz goes on to argue that (1) his moral psychology highlights fundamental shortcomings in ‘traditional’ normative ethical theories, (2) that moral progress is possible, despite the relativistic implications of his own position, and (3) that this undermining of the is–ought gap should hold true on any naturalistic metaethical theory, the extent to which his project succeeds becomes significant.