Simon Kirchin is Senior Lecturer in Philosophy at the University of Kent. He is the author of Metaethics (Palgrave, 2012), and the editor of Arguing about Metaethics (with Andrew Fisher; Routledge, 2006), and A World without Values: Essays on John Mackie's Moral Error Theory (with Richard Joyce' Springer, 2009). He is currently writing a book about thick and thin concepts.