Is natural law the answer?

Is natural law the answer?

This article was updated on 07 February 2021

When Christians consider whether and how to legislate morality, we’re immediately confronted with the fact we’re actually asking two questions:

  1. What should inform the content of public morality in an ideal sense? That is, setting present geo-political realities aside and focusing only on transcendent values, what is “the public good,” how can we know it, and to what extent should we advocate for it in the public square?
  2. How does the Church apply this public morality in real life, within the geo-political, pluralist realities that are the real world?

One way some Christians have answered the first question is to turn to natural law theory; specifically, a broadly Christian form of natural law. Is this a fruitful path?

What is natural law theory?

When we say, “natural law,” we mean it is “natural” in the sense that it reflects the nature, essence or intended form of something (X). “Law” refers to a normative dictum that explains what X, in light of its nature, should do in certain circumstances.1 This means human beings can (1) observe the nature and intended purpose of something, and (2) these observations form the basis for moral values and obligations.

So, to bring this down to earth, consider human beings. Natural law is our perception (even unwittingly) of the divine order within ourselves, by which we’re inclined to right action. We can observe ourselves, draw conclusions about our meaning and purpose, and so learn how we ought to behave. If you’re ever bored enough to read legal statutes, you’ll find that human laws are the result of a society’s reasoned application of general principles to particular cases for the common good. This is why even something so esoteric as the Washington State insurance code can proclaim:2

The business of insurance is one affected by the public interest, requiring that all persons be actuated by good faith, abstain from deception, and practice honesty and equity in all insurance matters.

It’s doubtful the Washington State legislature wittingly relied on natural law theory to craft this statute. Yet, there is an implicit appeal to such a law in that text. There is a public interest. Good faith can be known, defined, and it is “good,” (etc.). Indeed, some form of natural law must be the foundation for human law.3 Or else, we’re cast into the morass of subjectivism and individualism.

Christian natural law theory says scripture presupposes this divine ordering. David Haines and Andrew Fulford advance three propositions to express this idea:4

  1. there is an objective order to the universe;
  2. this order is objectively visible, there for all to see, “whether one is wearing the spectacles of Scripture or not;” and
  3. at least some unbelievers perceive this order.

They explain:

the very fact of divine creation seems to point towards what has been traditionally called natural law: the notion that there is, because of the divine intellect, a natural order within the created world by which each and every created being’s goodness can be objectively judged, both on the level of being (ontological goodness), and, for human-beings specifically, on the level of human action (moral goodness). Ontological goodness is the foundation of moral goodness.5

In one of his famous five “proofs” for God’s existence, Thomas Aquinas explained we can perceive God from the observable order of the world:6

We see that things which lack intelligence, such as natural bodies, act for an end, and this is evident from their acting always, or nearly always, in the same way, so as to obtain the best result. Hence it is plain that not fortuitously, but designedly, do they achieve their end. Now whatever lacks intelligence cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence; as the arrow is shot to its mark by the archer. Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God.

God, as it were, created everything as a carpenter plans and creates a piece of furniture.7 He sees an image in His mind’s eye, then executes that plan. Thus, God has a moral standard to which men are accountable, and His mind contains that “ideal” purpose and end of everything in His creation.

Scripture presupposes that this natural ordering and purpose exists. Here are but a few examples:8

  • Jesus’ so-called “Golden Rule” (Mt 7:12) presupposes that everyone, regardless of their spiritual state, acknowledges it is “good” to treat others equitably. This is as close to a universal moral good that one can get.
  • Deuteronomy 4:5-6. If the Israelites obey God’s laws, pagan nations “will say, ‘Surely this great nation is a wise and understanding people,’” (Deut 4:6). If unbelievers can look at God’s objective “good” and appreciate it, like it, acknowledge, want it—then there must be an objective “good” to define human flourishing. It isn’t a social convention; it actually exists and can be seen, known, appreciated.
  • In creation, God pronounced it all “very good,” which surely means there is an objective “good” to this world.

How, then, can we know right and wrong?

Well, first we need to understand that everything, including men, women, boys and girls, is made by God for a specific purpose or end. An ear is made to hear. A sock is made to fit on your foot. A book is meant to be read. A car is meant to transport you to and fro.

You can abuse the original design by using it in a way the designer didn’t foresee. For example, a neighbor of mine recently used his Jeep to prop up a section of fencing that had collapsed in his backyard. It “worked,” I guess, but it was crude. Why? Because the Jeep wasn’t designed to do that—it wasn’t its nature or raison d’être.

You could say there is a “fitness” and “unfitness” to everything, depending on its created purpose.

Thus fitness or unfitness may be affirmed, at every moment, of every object in existence, of the volition by which each object is controlled, and of every intelligent being, with regard to the exercise of his will toward or upon outward objects or his fellow-beings. Fitness and unfitness are the ultimate ideas that are involved in the terms right and wrong.9

So, consider marriage, children, government, attitudes towards elders, the sanctity of life, political society, political authorities—what are God’s purposes for these institutions? What is their nature? When you find that out—when you figure the ends for which God made them—then you have a secure base from which to understand and uphold these realities in the world.10

But, again, how can you figure out these ends? How can you know what they are?

Certainly, the Gospel of Jesus Christ gives one a new mind and a new heart, along with the illumination to understand divine revelation. Indeed, if God created a binding moral order, it seems He’d be remiss if He did not reveal Himself and this moral order to His creation.11

Not so fast?

However, natural law seems to not require this step. Instead, it asks one to reason from natural revelation—to extrapolate from the observable order to “think God’s thoughts after Him” in a whole host of modern contexts. Specifically, we can know right from wrong by considering various forms of the questions (1) what is the nature and purpose of the one doing the action,12 and (2) what is the purpose of the action, (3) what are the motivations behind the action, (4) what are the consequences, (5) what are the means by which we propose to accomplish this end, and (6) what are the circumstances surrounding the action?13

However, Haines and Fulford’s blanket assertion that when human beings observe human nature and draw conclusions about it, “we are thinking God’s thoughts after Him,” is not quite correct.14 Satan has thrown a dark cloak over people’s minds to “keep them from seeing the light of the gospel of the glory of Christ, who is the image of God,” (2 Cor 4:4). This a blindness to reality, including natural law, for which we must account. This means unbelievers will not always “see” the natural order flowing from a created order at all. Christians will usually have to do a three-step dance when pressing the reality of natural law; (1) it exists, (2) your sin stops you from seeing it in creation, and then (3) do you see it now?

Indeed, there are non-Christian theories about natural law predicated on secular bases. These contrasting theories “differ widely about what human nature is and, as a result, about the moral theory that can be derived from it.”15 Indeed, different schools of thought (even within Christian circles) disagree about the essence of human nature itself and, thus, the implications about the “ends” to be drawn from its nature. “Unless that picture can be firmly established in sufficient detail to warrant the moral inferences drawn from it, the theory as a whole will lack credibility.”16

So, for example, can we legitimately employ natural law theory to forbid birth control? After all, the reasoning goes, the “natural end” of marriage is procreation (or, is it!?), and birth control would impede this purpose, so it is morally wrong. It therefore seems that to be most persuasive, Christian natural law theory must function with some degree of abstraction.

Preliminary assessment

Nevertheless, does natural law theory provide the Church with a framework to understand the “public good” regarding legislation of morality in the public square? It does, but only obliquely. Simply put, why do Christians need natural law theory when they could just point to scripture? That, of course, is the rub—nobody wants to use scripture in the public square. Natural law theory, for all its promise, seems to be a method for reasoning “God’s way” while not actually pointing to anything God has said.  

Does it answer our second question? That is, does natural law theory help Christians “think God’s thoughts” via legislation in a pluralist society, in 2021? Haines and Fulford say it does:

The precisionists and the Anabaptists were wrong to deny that any just political order could be founded that did not submit to their own private and special revelation, since justice can be known from the wisdom in God’s creation.17

I am not yet convinced. To use just one example—people in the West simply do not acknowledge God’s justice or God’s objective order. Natural law theory appears to gravely underestimate the noetic effect of sin, which will inevitably prevent some people from agreeing with the specific implications of its general premises. In other words, while natural law theory supplies the Christian with some philosophical heft as a complement to a Reformed epistemology, I am not convinced it alone is a suitable vehicle for grounding moral values or legislation.  

I am very new to the concept of natural law theory, and perhaps I have misunderstood it here. But my assessment at this date is that it would be simpler to use scripture to advocate for God’s values in a pluralist society. In that respect, it reminds me of the debate between classical and presuppositional apologetics.


1 David Haines and Andrew Fulford, Natural Law: A Brief Introduction and Biblical Defense (Lincoln: Davenant Press, 2017), pp. 4-5. 

2 Title 48, Revised Code of Washington; RCW 48.01.030. Emphasis added. 

3 Haines and Fulford, Natural Law, p. 8. 

4 Haines and Fulford, Natural Law, p. 51.

5 Haines and Fulford, Natural Law, p. ii.

6 This is Thomas Aquinas’ “fifth way” of proving God’s existence from Summa Theologica, First Part, Q1 (“does God exist?”), A2.

7 “[T]he divine mind ‘contains,’ or is, the ideas of all created beings—what we call exemplar causes—in much the same way that the carpenter’s mind contains the idea of a finished table prior to beginning his work,” (Haines and Fulford, Natural Law, p. 23).

8 Haines and Fulford, Natural Law, pp. 52ff. 

9 Andrew Peabody, A Manual of Moral Philosophy (New York: Barnes, 1873), pp. 35-36. 

10 Haines and Fulford, Natural Law, pp. 24-27. 

11 Haines and Fulford, Natural Law, p. 51. 

12 The Westminster Larger Catechism sums it up nicely when it says, “Man’s chief and highest end is to glorify God, and fully to enjoy Him forever,” (Q1, A1).

13 Haines and Fulford, Natural Law, p. 38. 

14 Haines and Fulford, Natural Law, p. 44. 

15 Gerald Hughes, “Natural Law,” in Westminster Dictionary of Christian Ethics, revised ed. (Philadelphia: Westminster, 1986), p. 414.

16 Hughes, “Natural Law,” p. 414. 

17 Haines and Fulford, Natural Law, p. 111.