On page 243 of John Frame’s The Doctrine of the Christian Life, Frame writes, “Roman Catholics have argued that the case against abortion is not religious at all, but based only on scientific judgments about the nature of the unborn. So they oppose abortion by appealing to natural law.”
Frame continues by defining ‘natural law.’ He writes, “Natural law is understood to be a moral order, found in nature and in man himself. It is accessible through reason and conscience. Knowledge of it does not require Scripture or God’s saving grace.”
After raising a number of objections to natural law theory in general, he critiques a natural law argument against abortion on pages 247-248 as follows.
[I]f we set Scripture aside, the natural-law argument runs like this:
(1) It is wrong to take the life of an innocent human person.
(2) Abortion takes the life of an innocent human person.
Therefore, abortion is wrong.
But how do we establish from natural law alone the personhood of the unborn child, as presupposed in the second premise? Usually the argument is that the unborn child is genetically different from his parents and therefore not “a part of his mother’s body.” But there is a logical jump between genetic uniqueness and personhood. Genetic uniqueness is a physical property, but personhood is a moral one, implying moral rights. How can it be shown that genetic uniqueness conveys a right to life? I believe that Scripture teaches that the unborn child is a person, but it is by no means evident how that conclusion can be proved by natural law. So natural-law arguments often cry out for scriptural supplementation.
And if we can’t argue an ethical point from Scripture, it would be best not to argue it at all.
Frame is, in my opinion, on point. The temptation is to accept arguments for good conclusions without evaluating whether the argumentative methodologies employed to reach those conclusions are consistent with a Christian worldview. This phenomenon is particularly pervasive when it comes to the most passionately held ethical positions against such evils as abortion and racism. In the future, I hope to write more extensively on the place of natural law in a covenantal framework (no pun intended). Perhaps the way forward is to examine objections Frame brings against natural law theory, take a closer look at a potential example of the use of natural law in Scripture, compare and contrast natural law with natural theology, and finally address what all of this means for apologetic engagement.