Enhancement Biotechnology and the Natural Law

At the First Things blog, Ryan Anderson and Christopher Tollefsen have posted reflections about a natural-law approach to enhancement-biology questions.  It will definitely be of interest to MOJ readers.  A taste:

What might a natural-law appraisal of biotechnological enhancement look like? Much of modern ethics, especially when applied to biotechnology, springs from emaciated views of human nature. In response, a sound natural-law approach would need to begin with a twofold account of the nature of the human person.

The first part would be descriptive: Human persons must be shown to be human animals—bodily organisms of the species Homo sapiens. And the second part would be normative: Human persons must be shown to be fulfilled by certain ends and harmed by others. Both animality and rationality shape and define the constitutive aspects of our well-being, and critical reflection can identify the various goods that truly perfect us. . . .

Thoughts?