Abstract
Simon Blackburn can be seen as challenging those committed to sui generis moral facts to explain the supervenience of the moral on the descriptive. We (like perhaps Derek Parfit) hold that normative facts in general are sui generis. We also hold that the normative supervenes on the descriptive, and we here endeavour to answer the generalization of Blackburn's challenge. In the course of pursuing this answer, we suggest that Frank Jackson's descriptivism rests on a conception of properties inappropriate to discussions of normativity, and we see reason to reject descriptivism generally. We also discuss the views of David Brink, Jonathan Dancy and Bernard Williams in this area