The supervenience of the ethical on the descriptive

In his book From Metaphysics to Ethics, Frank Jackson attempts to find a place for the ethical in the physical account of the world, arguing that ethical properties such as rightness and wrongness are descriptive properties. His claim relies on his unrestricted global supervenience thesis, according to which two possible worlds, which are exactly alike descriptively, are exactly alike ethically. In this article, I argue that Jackson fails to demonstrate that ethical properties are descriptive properties. There are reasons for doubting his claim that ethical properties entail descriptive properties and that descriptive properties entail ethical properties. In addition, his notion of the directed nature of moral beliefs is inadequate to provide a satisfactory explanation of the normativity of the ethical.