Some other bloggers are promoting “natural law” as a concept crucial to public and political ethics, especially the current debate over whether two persons of the same sex can be married.
As a student of ancient philosophy and also of Scripture, I think our first question ought to be: Does the Bible consider natural law a criterion of ethics that can be appealed to in order to settle debates with unbelievers over the rightness or wrongness of a particular action? I consider this question to have been satisfactorily answered already in Markus Bockmuehl’s Jewish Law in Gentile Churches, and I would like to present some quotations from that book.
The perception of ‘nature’ and public convention is for the New Testament remarkably ambivalent as a source of moral authority, and needs in significant respects to be transcended. Both Paul and the Gospel tradition show a deeply subversive attitude to ‘natural’ morality, shaped largely by considerations of soteriology, eschatology, and resultant moral implications… The inauguration of the new age in Christ means that early Christianity is critically selective in its acceptance of earlier moral assumptions. Natural law is never simply identical with revelation, and can certainly never substitute for it.
The reason for this “deeply subversive attitude” is that for the Bible, creation is always defined in relation to the personal, Triune God and His purposes, while in pagan Greek philosophy, “nature” is not so defined. For Aristotle and the Stoics, nature is an unchanging given. It is both ontologically and epistemologically sufficient: it can serve as a source of moral precepts without the need for a personal God to give nature a telos, and men can know these precepts without the need for a personal God to interpret nature to them. (Neither Aristotle’s god nor the Stoics’ god is a person. They are, respectively, the unmoved mover, and the pantheistic world-spirit.) In Greek philosophy, nature is not part of a story that is headed anywhere, and so it cannot change when the plot takes a decisive turn.
By contrast, the Bible always presents the creation as conditioned by God’s purposes and ends, and to be understood in terms of them — which is to say, understood in terms of the Bible, which describes God’s plan and ends. Thus, a Christian definition of “nature”, like the Christian definition of “being”, is so thoroughly different from the pagan definition that it is fallacious to talk as though there were an unbroken tradition of “natural law” going back to Aristotle and Plato.
Thus Bockmuehl says, about Psalm 19:
The two main sections of the poem are linked by the phrase, ‘and nothing is hid from its heat’ (v. 7 Heb.), as well as by the repeated imagery of the Torah’s shining light (v. 9 Heb.). And it is precisely this easy juxtaposition of Torah and creation which prepares the way for the overwhelming assumption in Hellenistic Jewish writers that the Torah is self-evidently a law in full accordance with nature, indeed the most perfect expression of such a law. It is in this Psalm, then, that we get a glimpse of what became the mainstream view of natural law in Second Temple Judaism. This view is neither that there is a law of nature given in addition to the law of the Torah, nor that there is nothing but the Torah. Instead, creation itself demands life in accordance with the will of the Creator, and the Torah, or at least the principles it embodies, are the most perfect expression of a law that is in accordance with creation rightly understood…
Strictly speaking, there is no ‘natural’ law in Second Temple Judaism. That is to say, we have seen that neither the Hebrew Bible nor post-Biblical Jewish literature allows for a moral authority in nature that is somehow distinct from that of God himself. Law, inasmuch as it carries any real authority, is never ‘natural’ in the sense of being anything other than divine in origin.
The New Testament authors arguably make no explicit use of the Graeco-Rlman natural law tradition, as we shall discover; and this must be seen as an important caveat in relation to earlier studies of the subject.
In the past, scholars frequently considered Romans 2.14-15 to be the key New Testament passage on natural law. Paul seems here at first sight to allow for the possibility of a ‘natural’ law observance by Gentiles. Upon closer examination, however, the passage turns out to have remarkably little to say about the subject. At best, it allows for the possibility that some Gentiles might ‘naturally’ (φύσει) keep the requirements of the Torah.
Bockmuehl concludes that far from seeing nature as a source of law held in common with unbelievers, “the New Testament’s attitude to the concept of natural law is profoundly ambivalent. Appeals to nature are employed only where they fit ethical priorities that have already been established on other grounds.”
I’ve given only Bockmuehl’s conclusions here, but I recommend the book’s three middle chapters as a very convincing exegetical treatment of the question of natural law in the OT, 2nd Temple and early rabbinic Judaism, the NT, and the early church fathers.
Another book that is very useful for thinking about this question is Murray Jardine’s The Making and Unmaking of Technological Society. In it, he shows that even the core similarity between Christian and Greco-Roman natural law traditions — namely, the appeal to “nature” as a fixed and eternal norm not subject to man’s power to change it — is no longer plausible to modern thinking, and with good reason: with the advent of technology, human beings have discovered that they are able to change “nature”. It thus cannot any longer serve as a norm: a pianist who goes from playing the notes written in his score to composing the score himself cannot use the score as the norm for his music. (This is the development that C. S. Lewis feared in The Abolition of Man.) Jardine’s point is that, for good or ill (and Jardine thinks it is for good), this development has come to pass. And therefore, appeals to “nature” look absurd to modern man.
To conclude, in my opinion, the proposed return to “natural law” and the ius gentium is not only Quixotic in our day (Jardine), but also at odds with the way the New Testament’s authors use appeals to nature (Bockmuehl).
Above: Hugo Grotius