The reformed or Calvinist thinker Johannes Althusius (1557–1638) identified natural law (or common) as that law which God inscribed on the heart. Hence, it is common to all people, as God’s law in nature. God then uses our conscience to excuse or excuse us (Rom 2).
It is important to realize that this is the near-universal view of reformed thinkers from Amandus Polanus to John Calvin to whomever.
Natural law is not some law inside nature and apart from God, as Rushdoony believed, but rather it is the law of God inscribed upon our hearts as Paul the Apostle believed (Rom 2:14-15).
Where the rubber meets the road, however, is when it comes to obedience to God’s law.
The antinomian impulse, that is, the impulse to strive against God’s law occurs when we deny natural law, and the light of nature to discern the law of God.
This is what some have recently done to push back against complementarianism, for example. They deny natural law as a construct of Patriarchy (or something along those lines).
Some fundamentalists too took this view since they believed natural law which is not found in the Bible somehow made their piety less or the like. But that’s odd since the Bible tells us about the law of nature; and God created nature—so of course his law, his reason, his imposition must be everywhere. Why in the world would we want to deny reality? I cannot fathom it. But I lived it. I saw it. I even believed it at one point. Shame on me.
Interestingly, in some reconstruction circles, natural law is either pigeon-holed (e.g., John Frame, one sympathetic to reconstructionism, believes natural exists but in a very limited way), or denied it (Rushdoony, e.g.). The impetus among some reconstructionists (not all, I am sure) is to ensure that biblical (mosaic) law has pride of place over natural law, which at least in Rushdoony’s argument is a form of divinization of nature, in which nature has a law, apart from God.
This is exactly wrong. The law of nature is what God imposes on his creation, part of his eternal law, identical to the Ten Commandments (or nearly so).
When the Reformed and most Puritans talk about the law of God, then often mean the Moral Law, that is, the Ten Commandments, which is (nearly) identical with the Natural Law.
This is why every reformed thinker might be called a theonomist. I might be too. I argue that all must obey God’s law for human flourishing and to honour the Lord. By which I mean, God’s eternal law (identical to his being) as manifest in nature and Scripture.
But I would be completely wrong to obey some laws found in the books of Moses, which Scripture tells me have been abrogated—ceremonial laws and civil laws unattached to natural law. This I learn from the Bible itself as well as Calvin, Luther, and others.
That would mean I obey law NOT according to Scripture. I would be guilty of a form of legalism. Almost everybody—even those who take the name theonomist recognizes this. This is not meant to be a potshot.
The real difference here is how the civilly orientated laws work out today. I agree with Franciscus Junius that some civil laws, those which are necessarily attached to Moral Law, the Decalogue, persist though might need a practical application in the new era. But many are not, and some reconstructionists would want to pull in many more laws than I would.
So Rushdoony thought we should execute incorrigible children, gay persons, etc. I reject that teaching for many reasons, usually grounded in the kind of work that someone like Junius has written—he wrote “On the Mosaic Polity” to help the Netherlands use Mosaic Law in their administration of society. So this is not some anti-law person. In fact, he is a key 16th-century Reformed thinker.
But then one must also simply listen to Jesus:
“38 “You have heard that it was said, ‘An eye for an eye and a tooth for a tooth.’ 39 But I say to you, Do not resist the one who is evil. But if anyone slaps you on the right cheek, turn to him the other also. 40 And if anyone would sue you and take your tunic, let him have your cloak as well. 41 And if anyone forces you to go one mile, go with him two miles. 42 Give to the one who begs from you, and do not refuse the one who would borrow from you.”
Whatever else it means for Jesus to “fulfill” the law and prophets, it means that they centre on his teaching.
And here: we see something quite different from Israel’s theocratic society. And I suggest it strongly implies that Christians are not meant to create a theocracy as Israel had.
Of course, I do not mean we should pursue a godly society. But here is something, perhaps more controversial than, my other statements: Christ rules EVERYWHERE.
Imagine thinking that Christ only rules where biblical law is obeyed. I saw someone argue that recently on Twitter. (Yes, Twitter, but it was a prominent US theologian, so maybe it’s useful to cite here).
I cannot fathom such a notion. Christ rose from the dead and ascended to the right hand of God. His reign is universal. Christ knocked Satan to earth.
Christ rules over all by his Law. That Law of Christ, the eternal law of God, found in nature and in Scripture, evinces both natural and supernatural ends (Scripture alone gives supernatural ends, such as marriage imitates Christ’s love for the church).
All that to say, yes, to the Law of God! But don’t deny the law common to all in nature, inscribed on the heart, available to all through the Word who illumines every human being (John 1:9—see Amandus Polanus on this verse).
Don’t fall into a species of antinomianism by denying this law! Nor fall into a specifies of legalism by affirming law NOT according to Scripture, as in certain mosaic legislations which are shadows, a pedagogue, and often abrogated.