What is natural law?

Natural law theories have a long history with many different variants and scopes; thus, I couldn’t speak about them all in a blogpost. Instead, I will offer a provisional understanding of a natural theory as it is applied to the moral realm. Readers should understand that what I say here is not exhaustive, nor do I attempt to offer reasons to accept a natural law theory as true. My intent here is just to offer a basic sketch, leaving the project of justification for another blogpost.

Natural law theory involves at least three central ideas or commitments. The first idea or commitment is that some morally true claims, commitments or laws are implied or derived from facts about nature. Here I am talking about the metaphysical sense of the word nature, which implies a commitment to the essences of things or some other thing similar to essences. The second central idea or commitment is that some moral claims or propositions are objectively true; hence, natural law theory is not a kind of moral subjectivism. (See Hima, Natural Law, IEP). Thirdly, natural law theory, at least the form I defend, relies on something like the Aristotelian conception of the good.

The second and third central commitments or ideas, though they are of indubitable interest to philosophers, will not be addressed in this blogpost. Instead, I will focus on the first, because it is the distinctive and most contentious component of natural law theory.


Think of essences in two ways. Let me explain the two.

First, essences are the whatness of a thing (blue-ness, sour-ness, ball-ness, humanity, dog-ness, and so forth). These are not, properly speaking, physical or material things. They’re what we call forms: They are what organizes matter (in the Aristotelian sense) into the sort of structure, composition, properties, powers, and ends that a particular thing has. It is what makes a particular thing what it is. So for example, as I write this sentence, there is a thing next to me. What makes thing a dog is that it has the form of dogginess, which organizes his material composition into a dog-like shape, giving him sharp teeth and fur, an inclination toward social behaviour, and bad breath. I have different features than him because I do not have that essence (dogginess). Instead, I am human; hence, I have the essence of human-ness, which therefore accounts for why I have certain human properties, powers and appearances. And in addition to it being that which makes me human, it is also that which makes you human; and so it unites us as members of the human kind. It is thus the shared form of humanness that accounts for us being the same kind of thing while still existing as individuals.

Second, we know that some whatnesses are more basic than others. For example, consider my dog again. He has changed color, size and shape. He also lost his testicles when I neutered him. Yet, he went through these changes without changing who and what he is – a dog. He has also remained alive. Had he lost his dogginess or his life, he would no longer be a dog, nor would he be my dog. Thus, we say life and dogginess are more basic to being a dog than shape, color or testicles. Dogginess is core to his being. We can say similar things for human beings, though we have rationality and animality as our core. In each case, these core whatnesess bind us to a certain kind of existence, and these core whatnesses cannot be changed without changing the kind of things we are (what we call substantial change). This core whatness is the second sense of essence: It is this essence or whatness is what keeps me human through time passage of time and through accidental change.

Often times it is objected that it is not the human form that makes us human, giving us whatever ends, organizing our bodies, or unites us as a kind; instead, it is our DNA. This objection is misguided and its analysis is incomplete: We cannot simply settle for the fact that our DNA is and acts in ways that build human persons, nor even can we settle for the fact that our DNA is itself human. The question to be answered is why do any of our bodily parts act in human-characteristic ways, and why do any have human-characteristic powers and limitations, and why can any can be identified as human. The answer for the natural law theorist rests with our essence and the doctrine of form and matter. For them, the human form is that which ultimately gives the DNA its person-building end, making it and sustaining it as human DNA and none other.

This talk about forms and essence so might sound like metaphysical fluff, but it is likely a necessary postulate to make good sense of the world (see here). You might disagree, of course. But whatever you think about this realist position, the debate between realism and nominalism is one that you cannot avoid, because your answers to it, whether hidden, explicit or implicit, are necessary for any intelligible worldview. And I should further say that your answers have serious consequences for how we see the world and live within it.

Natural Goodness

So natures or essences is that which makes some thing what it is and also what it is not. They’re also objective features of realities and things, those that we cannot change without changing the sort of thing it is. Fair enough. If need more information about this, click here. If not, let’s move on.

When we know enough about a nature or essence, we know what makes a good instance of its kind. For example, as Edward Feser often points out, we know the nature of a triangle (triangularity); and so we can identify examples of good triangles and bad ones. For example, a good instance of a triangle doesn’t have obvious squiggly lines, but straight ones. We also know that, say, a good blue jay is blue and flies in the air. To the extent that a blue jay is not blue or does not fly, it is a bad instance of its kind – it is somewhat defective as the thing that it is. But to the extent that it does both, it is a good blue jay. Likewise for plants, too: A good pine tree is likely well rooted, green and tall, or whatever else, and a bad one has shallow roots and yellow color. And so on and so on.

We can call this natural goodness. Notice that what is good for a thing is embedded in the fact about what it is: Value cannot be strictly divorced from nature in these instances. Indeed, natural goodness is implied or derived from nature, which thus implies that the value/fact distinction cannot be applied in this circumstance, or at least not presumptively.

From Natural Good and Onward to Moral Good

But from here a person might object that what we are now talking about isn’t a moral good. These are just natural goods. And to the extent that we are talking about triangles and blue jays, they’re right. But if we talk about human beings, things change.

Humans beings have natures and a natural goodness no less than triangles and blue jays, but, unlike them, we have intellect and will. That’s important, because by its nature, our intellect is directed toward distinguishing between truth and falsity, and our will, by its nature, is directed toward pursuing that which the intellect distinguishes as good for us. Yet, what is objectively good for us rests in the fulfillment of our natural ends; hence, if we are to be rational, which would be perfective of our nature, then we our bound, as rational persons, to choose that which fulfills our natural ends and avoid what frustrates them. And furthermore, that we want what good for us is implied, necessarily, by the natural end of our will, for we always will what is good for us (a bank robber might know it is wrong to rob but he is still after that which he perceives to be a good). Thus, it is true that we want what is good for us; but what is objectively good for us is to be rational, pursue truth, avoid falsity, and fulfill our ends. Hence, if we want what is good for us, and we do, then we ought to be rational, pursue truth, avoid falsity, and fulfill our natural ends.

That last ought is a moral ought because the ends and flourishing of human nature is the basis for human fulfillment and good, and also because we are free to choose this good.

With this framework, we can see that we are morally obliged to do what is good for us qua human nature and avoid what is bad qua human nature. Some of the ways we judge what is bad or good for us qua nature is through determining our natural ends and the natural ends of our parts, faculities and powers, which, as you might expect, often leads to the infamous natural law positions against lying, masturbation, contraception, drunkenness, homo sex, and so forth.

But what is important to note here is that these conclusions follow from the framework – they are not the products of animosity or religious bigotry toward women who want “reproductive freedom” or homos who want to engage in homoerotic behaviour. These conclusions simply follow from an innocuous moral ontology; and consequently, their conclusions cannot be dismissed as bigotry, theology or animosity.

The Natural Law

So what is natural law? We can understand it as the disposition of things, at least those known to reason, to which all men must conform their will if they are to realize their end and good. The disposition of things pertain to natures or essences, which are objective parts of reality for all persons, regardless of time, place, thought, or agreement. That’s natural law.

And because we have a duty to realize our ends, we have a right to that which is necessary to meet that end. If these rights are infringed, then the very good of man and his person is assaulted. Hence, therein rests the objective and natural basis for our right to life, social engagement, freedom, conscience, and so forth. Contra Hobbes and Rousseau, it is not the state that is the basis or determiner of these rights, but the nature of man.  And contra whichever modern liberal quack, it is not the individual and his unbridled will that determines the good or his good, but his nature as a man.


That’s about all I will say in this post.


Oh, and Merry Christmas!


  1. I think the role of the fall is important in understanding nature. I opt myself for something like a divine preference theory of morality, but I do think “natural law” reasoning can be an epistemic tool used for understanding God’s will sometimes. But the world is not now as it once was, nor is it the way God intended it to be. Looking at nature will show a skewed and incorrect picture of the purposes of the things in question. But nature is not fully divorced from God’s intent, so it still shows some semblance of the “natural goodness” with which it was embedded. I think that the fall and the curse means that looking to nature will not suffice.

    • On this theological point: One possible reply rests in distinguishing the goods of our nature that original sin has impacted. Our natural inclination toward virtue has been diminished; our once holy nature, which was the created ingenuity of God, has been eradicated by Adam; but the goods of our nature, those concerning powers and ends, for example, have not been impacted by original sin. We can these goods of nature to help ground and know natural law.

      That said, this is a theological concern, and it shouldn’t interpose in any strictly philosophical assessment of natural law theory.

  2. I think it’s an understatement to say “our natural inclination toward virtue has been diminished.” How about replaced with an inclination toward vice and the re-branding of it as if it is virtue?

    The “goods concerning powers and ends” is unclear to me. I’m assuming this means something like inherent causal connections between A and B, like procreation being tied to heterosexual unions, etc. That’s not really true any more since we can create progeny through donation of gametes, but historically we can see nature organized to operate a certain way.

    You’re right, natural law theory could be correct in absence of our ability to know what nature is. I think most of my misgivings are epistemic in kind. However, I think that depending on how one understands “nature” it could really lead to an inverted sense of morality, since what appears natural in this fallen world is at times reversed from God’s intentions for it. I used to be less bullish about the effects of the fall, but over time I give it more and more efficacy and think less and less of the post-fall world with respect to God’s intentions.

    Additionally, I think natural law creates an unnecessary middleman between morality and God’s will. Why not just say that God’s will determines morality, since ultimately it’s his will that formed the basis of the creation of nature?

  3. I’m late to the party but:
    Living organisms, from the simplest, to the most complex, have one thing in common – the built in drive to survive. For what, though? That’s the $64,000 question. Why? Why do seventeen year locusts emerge from the ground to mate to reproduce, then die within 24 hours only to stay dormant for another seventeen years to then emerge and do it again?

    Purpose to good end is how I define all the parts coming together with but one goal – not just survival but eloquent, perfectly orchestrated reasons for each moving part to be. It is synergy. When the locusts emerge, their existence replenishes nutrients into the forest, not to mention a feast for the other creatures who gorge themselves. That’s pretty much all they exist for – though they don’t know it. Does this suggest Divine design? It does for me.

    The argument for the need for natural goodness as governed by natural law comes down to living things attracted to do that which builds and continues over that which destroys for the sake of survival. Whether one deems this from a theological or philosophical view does not change the actuality or the purpose. That there is a growing void of destruction that seems to suggest an antithesis exists that is determined to undermine the natural law of survival, can be seen as either theological or philosophical as well – depending on how one perceives natural negative force.

    I live on a two acre pond. Over the course of a decade I’ve had a front row seat to nature at it’s most raw. In a repeating annual cycle things live, things die, things are challenged daily just to survive. Somehow, each part contributes to the whole and it continues as a healthy ecosystem that’s been here for over half a century. Natural law, left alone, accomplishes what artificial law cannot.

    Just my two cents. 😉

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