Anyone who is familiar with the debate over natural law in Protestant theological ethics has likely heard it said: "The Protestant doctrine of sola scriptura and the Roman Catholic teaching on natural law are fundamentally opposed." According to the proponents of this view, natural law is a set of ethical imperatives drawn from human nature and known through reason and it differs thereby from any form of supernaturally revealed legal or moral instruction. While the opponents of natural law reference several lines of theological arguments to develop their case, perhaps the argument most frequently encountered in Protestant circles is that natural law makes God and Scripture irrelevant to moral knowledge. If that is the most common Protestant criticism of natural law, the second most common is that natural law turns a blind eye to the effects of sin on reason and human nature. When combined together, these two criticisms constitute the standard Protestant objection to natural law.