All explanations come to an end somewhere. The real opposition between Dawkins’s physicalist naturalism and the God hypothesis is a disagreement over whether this end point is physical, extensional, and purposeless, or mental, intentional, and purposive. On either view, the ultimate explanation is not itself explained. The God hypothesis does not explain the existence of God, and naturalistic physicalism does not explain the laws of physics.

(Thomas Nagel, “The Fear of Religion,” review of The God Delusion, by Richard Dawkins, The New Republic 235 [23 October 2006]: 25-9, at 26)