(I’ll take any excuse to jam both “grok” and “shtik” into the same headline.)
Now and then I find myself saying that you can accept Catholic teaching on [whatever, usually about gay stuff somehow] without being persuaded by or caring much about natural law theory. E.g. in the book I say, “This book is not a theological treatise defending the Catholic Church’s teaching on sexuality. I admittedly don’t always understand that teaching, and I don’t think you need to understand every single element of a Church teaching in order to assent to its authority in your life. And you certainly don’t need to accept any one school of theology–such as natural law–in order to accept and live by the Catholic ideal of chastity. If you do want to explore the reasoning and scriptural interpretation that shape the Church’s teaching, I’ve included some reading recommendations in appendix one, but you really don’t have to spend a lot of time on this stuff if you don’t want to.” (emphasis added)
A couple people have been confused by this, and that’s my fault. A helpful person on Twitter pointed out that the Catechism uses the term “natural law” to mean something inherent in all people, not a specific theological school. So my using this example is really confusing. Let me clarify here.
When I’ve been using the term “natural law” I’ve been using it to designate a school or style of philosophical/theological argument based on reasoning from first-principle goods to specific moral or political outcomes, in ways which attempt to be accessible to non-Christians.
So think of the sentence, “In this article, Robert P. George offers a natural-law argument against same-sex marriage.” That distinguishes George’s school of argument from e.g. a theology of the body argument. I’d expect George to talk about the purposes of sex and the sex organs, but not to rely on Scripture, whereas I’d expect a theology of the body argument for the same conclusion to invoke Genesis and discuss the “nuptial meaning of the body.”
As you can see, this is different from the Catechism’s use of the term, which is much broader. I completely forgot that the Catechism uses “natural law” (e.g. here) to mean something more like “our desire for God and our recognition that other people are equal to ourselves, which culture can obscure but which nonetheless remain written on our hearts.” In this sense the natural law is real and beautiful: It’s what allows the Spartan, however fleetingly, to recognize himself in the face of the helot–or the American to see the unborn child as someone like herself. It’s what makes humility possible even in cultures that despise humility.
If I’d remembered this I would have used a completely different example–I would have said, e.g., “You don’t have to be an adherent of the theology of the body to accept [Church teaching on marriage, or whatever].”