The Evidence of the Precepts of Natural Law

Is the Natural Law Persuasive? by R.J. Snell

The theory of natural law, not the precepts of natural law.

One can try to persuade not through demonstration of the principles (i.e. human goods), but through dialectic.

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.

While these goods are assumed in ethics, they can be shown to be such in metaphysics? What about the precepts dealing with the means to these goods? Can they be demonstrated (through moral science)? Even so, would such demonstrations be persuasive to the man of vice(s)? Probably not.

[We have a natural inclination to know truth. But moral truth is not the same "truth" as speculative truth.]