Natural Law in Catholic Social Teaching
a. Which law? What nature?
Whenever someone mentions “natural law” there is an immediate confusion that usually arises due to the contemporary understanding of the word “nature.” In modern usage we associate the terms “nature” and “natural” with the “natural world,” which is to say, the universal laws of physics and biology and all of the mechanisms that take place on this level. We don’t attribute to the word “nature” anything specifically human. It is taken as a context for all life rather than as a distinctive characteristic of a given being.
But when the Church speaks of “nature,” and especially when it speaks of natural law, it is speaking very differently. This is because natural law teaches that every being has its own “nature,” and that this imbedded nature also corresponds to an imbedded “natural law” which tends the being toward the perfection of its specific nature. It follows then that the “nature” in question will always be different depending on whether we are talking about a vegetable, an animal, or the human person. What is according to the “natural law” for one category of beings may not apply to another, because they have different natures. This is why the tendency to imagine “nature” as mere biological necessity applying to all material beings in the same way is a drastic oversimplification. Rather, when we are concerned with human behavior, we are concerned with man’s specific nature and, more importantly, his last end toward which this nature tends to move.
For example, we might say that sexual desire is “natural.” If we make the mistake of taking “natural law” to mean “biological necessity,” then we might end up drawing the conclusion that promiscuous sex is according to the natural law, since we see it all the time in animals and in fact this behavior is necessary to many of them. But we cannot transpose this principle onto a different nature—for example, onto human nature. Sexual desire is still in accordance with natural law for human nature, but only insofar as it reinforces the being’s development toward its ultimate perfection. While for certain animal natures this entails promiscuous sex, for man it does not. Sexual desire is therefore “natural” to man in a very different way than it is “natural” to animals, because man has different faculties and a different perfection which he must realize. He has a different nature and so the natural law does not direct him in the same way as it would direct a vegetable; likewise, the vegetable is directed very differently than a fish or a bird.
In order to gain a proper perspective on this subject, we must return to a more comprehensive notion of law capable of taking into account a hierarchy of orders and contexts, and which can deal with the diversity of life we find in the world. In traditional terminology, we must return to the three orders of law: eternal, natural, human.
b. Eternal law
Whenever we come upon a community of beings ruled by a sovereign who directs them toward their good, we come upon a law. If there are different kinds of these communities, they will be directed by a different kind of law. Now, the first and foremost of communities is the universe. The universe and every being within it are sustained in their very existence by the will of God and act in accordance with his rule. From this single rule, which is called eternal law, all other varieties of law are derived.
c. Natural law
In every created thing there is an inclination, impressed upon the very substance of the creature, drawing it toward certain ends. These ends are the mark of what the eternal law demands of that specific nature. It follows logically that this law will be different for each nature, depending on the end toward which the eternal law directs it. Man, for example, has divine beatitude for his end, whereas animals and vegetable life do not. And so, the inclinations of each will vary. When we obey this law which is “written on our natures,” we obey the law of our nature—our natural law. Because this natural law is really just the eternal as it pertains to us as men, then it is true that when we obey it we are participating in the eternal law. This is why it is said that the natural law is derived from and never contradicts the eternal law.
d. Human law
Why then, if there is a natural law written in the hearts of men, do we not find the same laws and customs in every society? Why, if all men possess the same nature and therefore the same natural law, does every society have different laws? The explanation for this lies in the third kind of law, which is called human law. The difference between natural law and human law is that natural law provides general precepts which are everywhere the same, while human law represents particular applications of these precepts. Because every nation and historical period differs and therefore has different needs, its applications of the precepts will be incredibly diverse, even though the precepts themselves will remain the same. This is a valid diversity so long as they accord with natural law and, through this, eternal law. It is only by ultimately deriving from the eternal law that any lower form of law has its validity:
“Human law is law only by virtue of its accordance with right reason; and thus it is manifest that it flows from the eternal law. And in so far as it deviates from right reason it is called an unjust law; in such case it is no law at all, but rather a species of violence.”
e. The precepts of the natural law
In order to understand why human law is diverse while natural law is said to be everywhere the same, we must remember that, much like how the Church offers principles rather than technical solutions, the natural law offers precepts rather than applications. And the first precept of the natural law is simply this: good is to be sought and evil avoided.
Further precepts are dictated by man’s nature: he is a being, he is a living being, and he is a rational being. Corresponding to these three facts about man’s nature are three natural precepts: first, man must conserve his being, which we call the duty of “self-preservation”; further, he must reproduce himself, raise his children, etc.; and last, which is specific to man as a rational being, he is to actively seek what is good. It is only due to this last feature that man can be considered “responsible” for his decisions. Animals, being irrational and therefore unable to rationally seek conformity with the natural law, follow it automatically and without their conscious assent. Only man can consciously participate in, or revolt against, the natural law.
From these observations we can begin to see why human law is diverse. Although the precepts are everywhere the same, we should expect that, depending on time and place, people will find various means of fulfilling these precepts. Also, because some of these men will make better use of their rational faculties, the various human laws will be more or less in conformity to the natural law. All will not be equal, although all can be said to be striving after the same justice.
f. Not everything in nature is natural
One further confusion needs to be set aright, if only because it is so common. Consider the following statement: “Whatever exists, is found in nature, and is therefore natural.” This way of thinking—called “naturalism”—leads to the rejection of any morality whatsoever, because it rejects the possibility of anything being unnatural. But we must recall that the Church does not speak of “nature” simply in terms of “everything that exists.” Certainly the Church acknowledges the totality of creation as “nature,” but it considers it as a grand diversity and within the context of natural law, which takes into account the particular end toward which a being tends. Considered in this way, if an action or behavior conforms with its proper end (or its “perfection”), then and only then is it natural. Thus, we can easily imagine acts which are in no way ordained to the proper end of the nature in question. For example, the sexual function and the pleasure associated with it are natural insofar as they conform to their obvious natural ends; they are unnatural when they do not. The deviant who seeks pleasure with himself alone short-circuits both the purpose of the sexual function and the pleasure associated with it. An analogous consideration can be found in the intellectual sphere: although human reasoning is performed by the “rational faculty,” no one would be naïve enough to claim that every decision produced by this faculty is therefore rational. Whether or not a decision is rational depends not on whether or not it is produced through the rational faculty, but whether or not it was produced in conformity with the laws proper to that sphere. It is entirely possible for the rational faculty to produce irrational conclusions. Returning now to the sphere of natural law, we must not lose our ability to distinguish the normal (“natural”) from the pathological (“unnatural”), simply because they both appear “in nature.”