In conversation with two prominent public intellectuals, both having significant influence within evangelical Protestant circles (and beyond), I was asked if natural law theory ever persuaded anyone not already on board. Both are sophisticated thinkers, little prone to the knee-jerk hostility against natural law occasionally found in certain evangelical sub-communities, and I took their query to indicate two reasonable concerns. First, the observable fact that debate doesn’t always persuade committed opponents, and second, the natural law’s unfashionable reliance on reason and nature, commitments beating hasty retreat in the face of postmodern suspicion.

Is the natural law persuasive?

The question posed is not whether the natural law works as a theoretically coherent account, but whether it can convince anyone, especially now, in our current cultural climate. Not, “is the natural law true?” but, “will anyone buy this theory?” Can natural law persuade?

The first concern is hardly unique to natural law, for any theory suffers its opponents and detractors, and debate is always slow and partial in winning over skeptics. The natural law doesn’t suffer any unique flaw in this respect. But while the concern would seem to apply to any and all ethical theories, natural lawyers ought to embrace the potential objection, allowing it full weight, and for two initial reasons. First, we claim that the natural law is not a theory. Certainly there are various accounts and theoretical articulations about the natural law, but natural law is itself always operative, always forming the way(s) human subjects operate, query, reason, judge, and choose. Hadley Arkes recounts the mistake of those who ask about his theory, forgetting that the grounds of reasoning and judging are the principles of natural law; when people asked about his theory, “they suggested a detached onlooker standing by, watching the theories whizzing past. And somehow they manage to make judgments on just which theories or fragments they find plausible or implausible, true or false.” But persons are able to make judgments of truth or falsity only because the natural law is already operative—it is the light of reason itself. Of course, if that is true, then failure to persuade would be noteworthy. Second, we claim that our principles are self-evident, and so it’s fair to press the failure to persuade.

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An adequate grasp of the natural law requires a first-person perspective. Natural law is not an “it” or a “force” or a “theory” existing out-there or in-here or up-there, but rather is the operator of our own subjectivity. As Germain Grisez articulates in an early essay, “law is not a constraint upon actions which originate elsewhere . . . rather, is a source of actions. Law makes human life possible. Animals behave without law, for they live by instinct without thought and without freedom. Man cannot begin to act as man without law.” That is, natural law is the dynamic source of our actions—including the action of reflexive theorizing about the source of our actions—and the source by which we reason or judge. “It” is not distinct from our own subjectivity, which is why Arkes responds incredulously to the query about his theory. Asking about his theory is tantamount to asking if humans have subjectivity. Well, who wants to know, and by what power do they want to know? It’s not a theory, it’s him.

The first-person aspect of natural law explains also the appeals to the self-evident. As John Finnis articulates in Fundamentals of Ethics, “ethics is not deduced or inferred from metaphysics or anthropology,” and principles are self-evident precisely in that they are not deduced from previous principles, but in no way is ethics merely intuited or asserted or mystically known. Rather, by adverting to the object(ive)s of human action—the for-the-sake-of-which rendering action intelligible—we can attend “to precisely those aspects of our experience . . . in which human good(s) became or can now become intelligible to us.” In other words, we can understand human goods rather than deduce human goods, but while understanding is not an inference it nonetheless involves insight into our experience, and without the experience and insight we would not understand. Basic goods are not deduced or derived, for they are self-evident, but there are conditions for our understanding of the goods.

The condition of coming to understand basic human goods, which serve as grounds for reasonable action, is a first-person understanding of our own reasons for acting. That is, we have to understand why we act and what we seek when we act. If an action is intelligible, that action will have some grounds which are understood as worth seeking in themselves, not requiring justification or demonstration on the basis of some other good(s). Understanding this entails self-understanding, adverting to the reasons for acting always operative in our knowing and choosing. Such self-understanding, Finnis explains, is not simply “opening one’s eyes” to take a look at oneself, nor is it an “intuition”; it is an “insight” gained by “reflecting on one’s own wanting, deciding and acting,” which occurs not by “peer[ing] inside oneself” but by noticing and understanding one’s own reasons for acting.

Space does not allow me to flesh out the entire account of natural law, obviously, but the first-personal element responds to both concerns of my two interlocutors. First, natural lawyers needn’t convince or persuade anyone, for in an important way natural law cannot be proven—law is the condition of intelligible action. Instead, our task is to have our interlocutors pay attention, not to us and our arguments, but to themselves. My failure to persuade someone of the natural law happens only if they (a) will not pay attention to themselves, or (b) if they do not understand themselves. Of course, I have neither power nor responsibility over another’s capacity to know themselves, so I’ll politely decline any such obligations for my ethics. In fact, since natural law is pre-theoretical, depending not on a system of concepts but rather on self-understanding, the more I grant that a theory must be able to persuade, the more that alternative theories such as deontology or utility fall while natural law survives, for they actually must provide a proof whereas I make no such claim, asking only for my interlocutor to advert to his performance.

Second, while I cannot prove the natural law—it not being that sort of thing—I can defeat objections to it through the method of retorsion or performative contradiction. The natural law is not a theory but rather the principles constituting our subjectivity, or as Grisez put it, there is no man without the law. The natural law thus constitutes my first-personal subjectivity, and, moreover, I come to understand the law through first-personal reflection on my reasons for acting and judging. While grasping subjectivity qua subjectivity cannot be granted by another, neither can subjectivity be denied without incoherence. Here I mean something more than logical contradiction, for as absurd as the statement “I lack subjectivity” is, the bizarreness occurs when I argue or judge that “I lack subjectivity” or “There is no natural law.” The natural law is both the power by which subjects judge (Arkes) and the understanding of intelligible reasons (Finnis), so the performance of judging or offering intelligible reasons thereby confirms the natural law. As Finnis claims in Natural Law and Natural Rights, “one who makes such an assertion, intending it as a serious contribution to rational discussion, is implicitly committed to the proposition that he believes his assertion is worth making, and worth making qua true.  . . .”

One can neither deny nor question the natural law’s persuasiveness except by asking questions, conducting inquiries, achieving understandings, reaching judgments, and making choices—all of which, if understood as the operations of our own subjectivity, are the natural law at work. And if one denies that one inquires, or understands, or judges, or chooses, one either contradicts what one is doing or one really does not inquire, understand, judge, or choose, in which case persuasion is not available to that sort of creature.

With respect to postmodern suspicion, this articulation of the natural law grounds itself in no big claims about Reason or Nature or Metaphysics. Although every account intertwines itself with big theories, natural law is not grounded in them, for it claims no foundations from which it is derived, pointing only to the easily observable (even by postmodernists) data of their own questions and judgments and the fact that the more someone suspects and argues against my account the more they refute themselves.

The natural law is persuasive because it requires nothing more than a willingness to advert to one’s own self, although, to be sure, even Socrates knew the difficulties in getting people to meet themselves for the first time.