Jesse Hambly

In this paper I develop an argument against applying a causal theory of mental content to normative concepts. This argument—which I call the Intrapersonal Normative Twin Earth Argument—is inspired by Terry Horgan and Mark Timmons’ Moral Twin Earth Argument. The focus of Horgan and Timmons’ argument is showing that causal theories of mental content conflict with plausible claims about interpersonal normative disagreement. The Intrapersonal Normative Twin Earth Argument, by contrast, is focused on showing that such theories struggle to vindicate plausible claims concerning whether two of an agent’s token normative thoughts have the same or distinct content.

Moral metasemantic theories explain how our moral thought and talk are about certain properties. Given the connection between what our moral terms are about and which moral claims are true, it might be thought that metasemantic theorising can justify first-order ethical conclusions, thus providing a novel way of doing moral epistemology. In this paper, we spell out one kind of argument from metasemantic theories to normative ethical conclusions, and argue that it fails to transmit justification from premises to conclusion. We give three reasons for this transmission failure, which together pose a serious challenge to such metasemantic arguments.