Richard Y. Chappell

The aim of this paper is to assess the relationship between anti-physicalist arguments in the philosophy of mind and anti-naturalist arguments in metaethics, and to show how the literature on the mind-body problem can inform metaethics. Among the questions we will consider are: (1) whether a moral parallel of the knowledge argument can be constructed to create trouble for naturalists, (2) the relationship between such a "Moral Knowledge Argument" and the familiar Open Question Argument, and (3) how naturalists can respond to the Moral Twin Earth argument. We will give particular attention to recent arguments in the philosophy of mind that aim to show that anti-physicalist arguments can be defused by acknowledging a distinctive kind of conceptual dualism between the phenomenal and the physical. This tactic for evading anti-physicalist arguments has come to be known as the Phenomenal Concept Strategy. We will propose a metaethical version of this strategy, which we shall call the `Moral Concept Strategy'. We suggest that the Moral Concept Strategy offers the most promising way out of these anti-naturalist arguments, though significant challenges remain.