New Natural Law, Derivationist Natural Law, and Evolutionary Debunking

Abstract

Evolutionary debunking arguments attempt to show from the fact of evolution either that there are no evaluative truths existing independently of our evaluative judgments or that we lack knowledge of such truths. In this paper, I consider whether Sharon Street’s influential evolutionary debunking argument threatens natural law theory. I argue that new natural law theory is vulnerable to her argument but that derivationist versions of natural law theory (sometimes referred to as “traditional” or “old” natural law) have the resources to mount a defense. I show that new natural law theory’s account of how we know the precepts of natural law leaves the theory open to Street’s attack. I also show that derivationist natural law theory’s account—on which the precepts of natural law can be derived from facts about human nature and human fulfillment—gives deriviationists what they need for a defense.