Why Aren’t Natural Law Arguments More Persuasive?

As an evangelical who is extremely sympathetic to natural law theorizing, I have been fascinated by the recent discussion that Joe Knippenberg mentioned earlier today. However, I’ve been surprised that while many have hinted at it, no one has directly asked the obvious question: Why aren’t natural law arguments more persuasive?

We evangelicals are nothing if not pragmatic. If we were able to recognize the utility and effectiveness of such arguments, we’d likely to be much more open to natural law theory. But conclusions based on natural law don’t seem to be all that useful in compelling those who are unconvinced. Indeed, not only do that not seem to change the minds of non-believers, they often fail to sway believers. For instance, nominal Catholics, a group that should (at least theoretically) give them a fair hearing, don’t seem to take such arguments all that seriously. Why is that?

We evangelicals, of course, have our own explanation for such arguments are inefficacious. As Al Mohler said after an interview with Robert George:

At the end of the day Professor Robert P. George really does believe that the natural law can in itself form the basis of a compelling moral argument for such an issue such as sexual restraint. I have to come at this from a position that is more informed by Romans chapter one. When I believe that what we are told there is that humanity is dead set to suppress the truth in unrighteousness and that there is no law written within the heart nor within the role of nature that will keep them from doing what they are determined to do except by the regenerating power of God, the gospel of Jesus Christ. There is a restraining grace and for that I am very thankful and I do not deny the reality of the natural law. I do not deny the fact that that is a part of the restraining grace, but at the end of the day, I am not very hopeful that a society hell bent on moral revolution is going to be held in check by our arguments by the moral law, the natural law. I’m thankful, however, that Robert P. George is making those arguments. I’m thankful that he’s making them better than just about anyone else is making them. And as an evangelical, we have every reason to use natural law arguments, we just don’t believe that in the end they’re going to be enough. That’s where we have to come back with the final issue always being the gospel. And the challenges we’re talking about today are the challenges that point to the absolute necessity of the gospel of Jesus Christ. That’s where we begin and that’s where we end.

As much as I’d like to agree with Dr. George, I have to side with Dr. Mohler: Evangelicals have every reason to use natural law arguments, we just don’t believe that in the end they’re going to be enough.

Of course, that is not to deny their importance or to say that they should be used. I believe that natural law arguments can be valuable even when they are never fully persuasive.

Nevertheless, many natural lawyers do intend for such argument to persuade both believers and non-believers. How do they account for the relative ineffectualness of such arguments? Why don’t more people find them to be persuasive?

I’m sure this questions has been considered by natural law advocates, so I’d love to have them weigh in on this question.