Judicial access to the natural law?

Hadley Arkes's new book, Constitutional Illusions and Anchoring Truths (Cambridge, 2010), raises (in that elegant Arkes way) lots of interesting questions, including the one about judicial access to the natural law.  Arkes and I disagree, to some extent, on how to frame the issues concerning judges and the natural law, but we are united in bebunking the default legal positivism of much contemporary American conservativism.  You can read more here.