As we shall see, the teaching of the NT on natural law stands in continuity with the OT and most extracanonical Jewish literature. Throughout this series, I have sought to prove the following three  hypotheses, which are what I mean by the term “natural law”:

(N1) there is an objective order to the universe of the kind described above

(N2) this order is objectively visible; it is there to be seen, whether one is wearing the spectacles of scripture or not

(N3) at least some unregenerate people perceive this order

Jesus

The teaching of our Lord provides several examples of natural law reasoning. Most of them, in fact, are among his most memorable sayings. For example:

Matthew 6:25 “Therefore I tell you, do not be anxious about your life, what you will eat or what you will drink, nor about your body, what you will put on. Is not life more than food, and the body more than clothing? 26 Look at the birds of the air: they neither sow nor reap nor gather into barns, and yet your heavenly Father feeds them. Are you not of more value than they?

Jesus appeals to objective facts about the natural world, including God’s providence for animals, and the obvious superiority in value of human beings to those animals, to draw practical conclusion: do not be anxious about your life. This kind of reasoning at least affirms N1. That Jesus even appeals to the realm of nature, rather than simply quoting OT commands or issuing new bald diktats, strongly implies support for N2.

Another example of natural law in Jesus’ ethics is his famous “Golden Rule”:

Matthew 7:12 So whatever you wish that others would do to you, do also to them, for this is the Law and the Prophets.

As Dr. Bockmuehl notes: “the uncomplicated assumption of a kind of natural reciprocity and commonality of human needs suggests the acceptance of a moral category that is general and self-evident, rather than positively revealed in the Torah.” ¹

This teaching deserves a bit more meditation. Firstly, Jesus teaches his disciples to take their own basic desires as ones that every human being has. Secondly, by telling them to satisfy those basic desires of others, he affirms those desiderata as good. The implication of these two premises is that Jesus teaches all people actually know what is good for them, on some level, since they have desires that ought to be met. Thus in this brief rule, Jesus affirms N1, N2, and N3. And, of course, this rule is known as the “golden rule” partly because it is so foundational (Jesus says it sums up the ethical teaching of the entire OT), but also because examples of it show up in all cultures. It remains part of the philosophia perennis. ²

Another famous example (noted by Dr. Bockmuehl ³) of what people now call natural law ethics shows up in Jesus’ teaching on sexuality, more specifically divorce. In Mark 10:6-8 and its parallels, Jesus corrects Pharisaical views about this practice by pointing them back to God’s originally created order. A particular point of grammar in Jesus’ appeal makes this clear:

Mark 10:4 They said, “Moses allowed a man to write a certificate of divorce and to send her away.” 5 And Jesus said to them, “Because of your hardness of heart he wrote you this commandment. 6 But from the beginning of creation, ‘God made them male and female.’ 7 ‘Therefore a man shall leave his father and mother and hold fast to his wife, 8 and the two shall become one flesh.’ So they are no longer two but one flesh. 9 What therefore God has joined together, let not man separate.”

Matthew19:4 He answered, “Have you not read that he who created them from the beginning made them male and female, 5 and said, ‘Therefore a man shall leave his father and his mother and hold fast to his wife, and the two shall become one flesh’? 6 So they are no longer two but one flesh.What therefore God has joined together, let not man separate.”

In both texts, the Greek word απο appears, translated “from.” What Jesus’ words actually communicate, then, is that God made at the beginning, and continues to make, people male or female. Jesus goes on to explain that this perennial natural reality of two sexes is aimed (Matt 10:7, Mark 19:5; ἕνεκα/ἕνεκεν “therefore”) by God at their union. Because this union is God’s intention in marriage, Jesus says, we ought not to oppose God’s intention by separating these two joined. Thus, the logic of the argument runs like this:

1. God created the male/female order of nature at the beginning in Eden, and he has sustained that order in being since then
2. God’s aim in this two-sex order is that the sexes become united in marriage
3. Therefore, since God intends the union of the sexes in marriage, no mere human being ought to break the union when it has been accomplished; that would be to oppose God’s intention in nature

At minimum, this affirms N1.

These are by no means the only instances of reasoning from the “objective value” of the cosmos in Jesus’ teaching, but they are sufficient for the point. Jesus’ mission was to restore God’s world to the Creator’s original purposes for it, and his practical guidance constantly directed his disciples to act consistently with this end.

Paul

Above all figures in scripture, discussions about natural law in the Bible rightly center on the teaching of the Apostle Paul. This should not surprise us: of all biblical writers, the Apostle to the Gentiles was the one most energetically engaging those outside of Israel, those who did not have the Torah, with the demands of God, and so he was the one most likely to have use of natural law concepts. He mentions the word “nature” several times, and engages in natural theology and natural law ethics.

Acts 14

After the healing of a crippled man at Lystra, the local inhabitants became convinced Paul and Barnabas were Greek gods. In response to this error, Paul proclaimed:

15 “Men, why are you doing these things? We also are men, of like nature with you, and we bring you good news, that you should turn from these vain things to a living God, who made the heaven and the earth and the sea and all that is in them. 16 In past generations he allowed all the nations to walk in their own ways. 17 Yet he did not leave himself without witness, for he did good by giving you rains from heaven and fruitful seasons, satisfying your hearts with food and gladness.” 18 Even with these words they scarcely restrained the people from offering sacrifice to them.

Paul argues that it is not fitting to worship himself and Barnabas because their nature ⁴ was merely human. Of course, Paul could have cited the Shema, or the First and Second of the Ten Words, but instead he reasoned with the citizens of Lystra based on what was objective in the structure of the world: it was simply a matter of fact that as human beings, Paul and Barnabas were not worthy of worship. This assumes N1 clearly and N2, but also perhaps N3, in that Paul expects his hearers to see his argument as sound.

The apostle proclaims the true God to the pagans, and notes that in the past this God let history run without interference, but now that things will be different. And then he qualifies this statement, to note that while “now” God will not simply let paganism continue, yet even “before” God was not totally “hands off” with pagans. Rather, all along he has been testifying to them. The implied testimony, given the context of verse 15, is that they should be worshipping the true God only. And what is the content of the testimony? According to verse 17, it is God’s continual provision of “rains from heaven and fruitful seasons, satisfying your hearts with food and gladness.” That is, the testimony just is the fact that natural processes continue to aim at, and reach, their appointed goals, and that these goals dovetail together with what human beings need for their own happiness. This testimony makes known a benevolent Creator who deserves our complete devotion. In essence, Paul presents Thomas’ “Fifth Way,” noted at the beginning of this series. So in this text, Paul clearly affirms N1, N2. Assuming God is a competent testifier, we can deduce that this testimony was sufficient to be visible to these pagans even in their unregenerate state. This implies N3. Not making this assumption would imply God was testifying in such a way that he knew nobody would perceive.

Acts 17

The more famous of Paul’s “natural theology” speeches in Acts is no doubt his Aeropagitica. The most important section of that address for our purposes is:

26 And he made from one man every nation of mankind to live on all the face of the earth, having determined allotted periods and the boundaries of their dwelling place, 27 that they should seek God, and perhaps feel their way toward him and find him. Yet he is actually not far from each one of us, 28 for ‘”n him we live and move and have our being”; as even some of your own poets have said, “For we are indeed his offspring.” 29 Being then God’s offspring, we ought not to think that the divine being is like gold or silver or stone, an image formed by the art and imagination of man.

Paul quotes Epimenides of Crete and Aratus’s “Phainomena” to bolster his Jewish theology, but we need to consider the implications of these citations. Paul regards these writers as expressing truths about the world. This would imply N1, as they are truths about the world, but also N2 and N3, since pagan poets are reporting these truths. Paul then reasons from his natural theology to conclusion about the use of images in worship (verse 29). Again, this must assume N1 at minimum, but in that the apostle was giving an argument to unbelievers, it may imply N3.

Romans 1:17-32

The locus classicus for natural theology, without question, is Romans 1. The apostle makes several facts clear in this stage of his extended argument. In the previous verse, Paul declares the solution to the problem of the whole human race. In verse 17, he begins to state the problem. Later, beginning in chapter 2, he will start to describe the Jewish problem in particular. But in 17-32, he focuses on the non-Jewish problem. And that problem is God’s wrath, which comes because the Gentiles have committed a specific sin. That sin is described in various ways:

• suppressing the truth (18)
• knowing God yet not honouring or giving thanks to him (21)
• exchanging the glory of God for images of creatures (23)

This culpable suppressing of God’s revelation leads to further sin, as God withdraws his restraining grace. First it leads to worship of creatures. But it also leads to equally “unnatural” (παρὰ φύσιν) acts–acts which defy the obvious structure of reality just as much as dishonor of the Creator does–on the level of sexual behaviour (24-27). Dr. Robert Gagnon’s analysis of this text’s relation to its preceding context compels agreement. In one part of that analysis, he writes:

The insertion of 1:25 was Paul’s way of reminding the reader of parallels between idolatry and same-sex intercourse that made the punishment so appropriate for the crime. In their vertical relationship to God the gentiles ignored the obvious truth about God visible in creation in order to pursue an absurd course of action–a course of action that they alleged was a product of wise rational reflection. God responded to their idolatry with the punishment of allowing them to debase their bodies in their horizontal relationships with one another. With no divine restraint on their passions, they continued to ignore the obvious truth–now about heterosexual complementarity so evident in nature–and pursued the absurd course of action of having sexual intercourse with members of the same gender. The correspondences can be laid out as follows [with “the key parallel being the absurd denial of natural revelation in one’s worship of God and intercourse with other humans”]:

Idolatry	Same-Sex Intercourse
vertical relationship with God	horizontal relationships with each other
suppressing visible evidence in creation	contrary to visible evidence in nature
in the sphere of the mind	in the sphere of body and passions
human decision	divine handing-over
exchange of God for idols	exchange of opposite-sex for same-sex
not glorifying God	dishonoring themselves
foolish act	self-degrading behaviour 5

And it results in the laundry list of sins described in 28-32.

Paul concludes with this statement (32): “Though they know God’s righteous decree that those who practice such things deserve to die, they not only do them but give approval to those who practice them.” At this point in his argument (which began in 17), Paul has not used the word “decree.” To determine the identity of this decree, then, we need to consider Paul’s implied background. The most probable interpretation is that this “decree” is precisely what we call “natural law.” Firstly, we should consider that the Greek term Paul uses, δικαίωμα, could be used by someone like Josephus to refer to natural law:

Antiquities 17.108: Although he owned that he was not so much surprised with that thoughtless behavior of his former sons, who were but young, and were besides corrupted by wicked counsellors, who were the occasion of their wiping out of their minds all the righteous dictates of nature, and this out of a desire of coming to the government sooner than they ought to do… ⁶

Secondly, we must remember the survey of OT concepts above, and note that the scriptures described the order present in nature as an expression of God’s decree. For example, Psalm 33:6-9 ⁷:

6 By the word of the Lord the heavens were made,
and by the breath of his mouth all their host.
7 He gathers the waters of the sea as a heap;
he puts the deeps in storehouses.
8 Let all the earth fear the Lord;
let all the inhabitants of the world stand in awe of him!
9 For he spoke, and it came to be;
he commanded, and it stood firm.

The order of nature, according to Jewish thought, is a manifestation of God’s will, God’s imperial command. Through its wisdom and logic, one can perceive the will of the Creator. It is this wisdom, this decree, that the Gentiles as a whole have defied.

Romans 1, then, affirms N1, N2, and N3. But, before moving on, we should make one further comment. Let us grant, for the sake of argument, that as a small minority of (mostly Barthian) exegetes have argued, this text is not really about natural revelation, but rather special revelation. ⁸ Still, no interpreter can reasonably deny that Paul is imputing knowledge of God’s being and commands to people who are still in unbelief. Thus we cannot say that only regenerate people possess knowledge of God’s will. Even if we deny this text supports N1 and N2, it still must support a modified version of N3 in relation to divine positive law. And when we combine this point with the abundant evidence we have already seen for N1, the usual theological motives for denying that this text speaks of natural revelation seem to be undermined.

Romans 2

If Romans 1 is the locus classicus for natural theology, Romans 2 presents the same for natural law especially. However, the argument of scholars like Dr. NT Wright ⁹ and Dr. Simon Gathercole  provides a strong case to read the passage otherwise, as referring to the hearts of regenerate Christians who experience the promise of the New Covenant law written on their hearts, rather than to unregenerate pagans obeying natural law.  The debate on this matter is ongoing, and probably could occur between contributors to TCI; in the case that the traditional reading is correct, there is yet another proof for the classical Christian position on natural law. The reader must sort out this matter to their satisfaction.

However, it is worth speaking of how Paul uses the language of “nature” on the interpretation I would defend. Dr. Wright argues that in Rom 2:14, Paul writes of the  “Gentiles who do not have the law by nature,” in contrast, implicitly, to the Jews who do have the Torah by “nature”. ¹⁰ In this case, Paul’s language fits neatly into the scholastic category of “second nature,” which is a kind of habit or custom. Race or ethnicity, with its complex history and social practices, is something one is born into ¹¹ (like true nature), and something that powerfully shapes the kind of persons that people become. Thus individuals of the Jewish nation, by virtue of their social history, in this sense possess their heritage, especially the Torah, by (second) nature.

Yet this does not imply that everything Paul, or the Bible, describes as “nature” is socially constructed the way that race is. Quite clearly in Paul’s mind, the nature of the sexes is an example of something God created in Genesis 1 and 2. Dr. Robert Gagnon’s The Bible and Homosexual Practice shows how Paul is alluding to the creation narrative while he speaks of homosexuality, ¹²  revealing how closely God’s original creational intentions and the nature of the sexes are bound together in the apostle’s mind. And further, to suggest that, for Paul, the creation order we have been discussing throughout this essay is entirely socially constructed would be just for him to deny there is any creation order at all. Clearly, the apostle means something other than that.

Ephesians 2

In the midst of a description of the state of fallen humanity, Paul speaks of how we (vs. 3) “were by nature children of wrath, like the rest of mankind.” This is another case of what the scholastics would call “second nature”.  However, unlike race, Paul now speaks of a different kind of construction: sin. In fact, it would be more accurate to call this a destruction, for that is what sin really is. Sin is a habit all human beings possess from birth that drags human beings away from their God-intended telos, and towards utter ruin.  This propensity towards evil consequently calls down the wrath of God, and hence by (second) nature we are subject to God’s wrath.

1 Corinthians 6

Returning to positive proof for natural law in Pauline ethics, 1 Cor 6:18 provides a good example of the concept without the word. The apostle writes that “the sexually immoral person sins against his own body.” In other words, to sin sexually is to offend against the right order inscribed by God into the body he created for you. It breaks the natural law God decreed. This proves N1, though perhaps not N2 or N3.

1 Corinthians 11

The other frequently discussed Pauline text on natural law comes in the apostle’s teachings on headcoverings. Paul writes:

13 Judge for yourselves: is it proper for a wife to pray to God with her head uncovered? 14 Does not nature itself teach you that if a man wears long hair it is a disgrace for him, 15 but if a woman has long hair, it is her glory? For her hair is given to her for a covering.

Dr. Bockmuehl provides what is probably the correct explanation of this text:

The particular argument of this passage, however, derives from the fact that in this context the perversion of hairstyles denoted a perversion of sexual identity. For a man to wear female hairstyle was a way of communicating effeminacy and thus homosexuality.  It is likely, therefore, that for Paul men’s long hair is ‘unnatural’ not just by common convention or sentiment, but especially because of what it is perceived to denote in the moral realm.  As we saw in Romans 1, both Paul and Hellenistic Judaism decried homosexual acts as instrinsically contrary to the created order. ¹³

To attempt to elaborate: the created order implies homosexual actions of any kind are unnatural. That is, not simply homosexual sexual acts, but behaviour in general that today might be called “gender bending.” Rather, according to the Jews and the Christians, nature teaches that people should behave as the sex they are. But of course, no one lives as a sexed being in isolation; all people must participate in societies, which have socially established conventions for the sexes. Thus, nature dictates that people behave as their own sex in relation to others in society, and thus behave according to the social conventions for sexes established by the society they are in. ¹⁴  The present text addresses one such convention, that of hairstyle. ¹⁵

Of course, social conventions can require sin, and Paul cannot be ignorant of this fact. But he also, apparently, does not consider women wearing conventional female hairstyles (nor men male ones) and veils to be a sinful demand on the part of culture.

Jude 

The last text in our survey shall be Jude 7. The brother of James writes that the inhabitants of Sodom and its surrounding cities “pursued other flesh.” The ESV correctly paraphrases this “pursued unnatural desire,” for the sexual sin Genesis explicitly marked out was their desire for the other-than-natural relations of homosexual intercourse. Jude writes that those cities stand as an example of punishment for that behaviour. This implies N1, and assuming God does not punish people for disobeying orders of which they were invincibly ignorant, it would seem to imply N2 and N3 as well.