Ilan Wurman CMC '09-10 has a review of Harley Arkes's new book, Constitutional Illusions and Anchoring Truths: The Touchstone of the Natural Law, over in The Weekly Standard. Here's an important graff from the review.
All of this is to say that morality and natural law are undeniably part of the legislative process in any political body, and judges must understand the moral intent of laws in order to pass sound judgments. But it is not the role of judges to come up with new canons of reason and natural law; that is the role of statesmen and legislators. It is worth remembering, despite Arkes’s plea that natural law and moral judgment are based on a moral sense and are accessible to everyone, that the tenets of natural law are hardly accessible to all men. The greatest natural law thinkers—from Plato, Aristotle, and Cicero, to Hobbes and Locke—have disagreed on the content of natural law. So we should remember why we go back to original intent and the written text of the Constitution: because the founding was an act then and now consecrated for its unique confluence of great minds and great wisdom. The principles of the Constitution were rooted in historical experience and natural law, and judges must understand those principles to understand the Constitution.