If we are honest, we have to acknowledge that, in fact, various textual provisions stand as signs or expressions of precepts that may be traceable to natural law. And, if the Declaration of Independence has a constitutional status, we can see there an embrace of a form of natural law (or natural right)—not Thomistic, but Lockean (with a twist from the Scottish Enlightenment). The second reason that many reject natural law as a source for constitutional meaning is that it is too abstract and too contestable to provide constraint and direction. Put more directly, it is simply a cover for the imposition of personal predilection. This was Justice James Iredell’s worry in Calder v. Bull. It is a non-trivial concern. But, if natural law can survive the criticism that it is fatally indeterminate, it cannot be dismissed categorically as an aid to constitutional interpretation.
Originalism and Purpose: A Précis,
U. Pa. J. Const. L.
Available at: http://scholarship.law.upenn.edu/jcl/vol16/iss2/4