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Natural Law

The moral laws, like the physical laws, tell us how to handle ourselves harmoniously with reality…We can ignore them or flout them, by walking over a cliff, for instance, or stealing: but the law of gravity is not broken in the one case or the law of justice in the other. Both laws continue to operate and it is we who are broken (Frank Sheed, Society and Sanity, Ch. VI).

We live in a world bound by laws: the law of gravity, inertia, entropy, etc. These laws do not admit concession only consequence. The man who jumps off a high rise does not defy gravity; he merely demonstrates it. 

The moral laws are no less relenting. As drowning smothers the life of the body, so drunkenness snatches it from the soul (cf. Gal. 5:21). 

For either law: the physical or moral, violation brings with it a corresponding loss of life and the less acquainted we are with these laws the more likely they are to injure us.

The proof of which is found, quite tragically and scientifically, in today’s youth.

Lawless Sadness

According to Barna Research, Gen Z is the most morally relativistic generation of the last century and also, according to a recent study out of Harvard, the saddest.1 In the words of the Director of the Human Flourishing Project at Harvard:

Across every dimension of well-being that we looked at — happiness, health, meaning, character, relationships, financial stability..Those who are 18 to 25 felt they were worse off across all these dimensions. It was pretty striking, pretty disturbing (The Harvard Gazette, Why are young people so miserable?).

I would contend that Gen-Z’s worse off (specifically in the realms of meaning, character, and happiness) are the result of living less humanly: living contrary to the natural law.

Apart from the Harvard study, a systemic “worse-off” is also evidenced by the increasingly medicinal character of our age: whether by media or marijuana (both at record levels in America).2 It seems our culture is trying to take the edge off a wound. Perhaps, the wound coming from a broken moral law, which has (in its turn) broken its offenders.

Consequently, to live humanly and happily, we must uncover that law within which it is possible. As Sheed puts it, in regard to both physical and moral law:

In any case there is no such thing as freedom from them: but only freedom within them. And freedom within them can be attained only by one who knows them (Map of Life, Ch. II).

This law wherein is the freedom for human happiness, as discoverable by reason alone, is the Natural Law. The articulation and defense of which will be our present pursuit as we describe a law which leads to life.


What is law? According to St. Thomas Aquinas:

law…is nothing else than an ordinance of reason for the common good, made by him who has care of the community, and promulgated (ST, I-II, Q. 90, A.4).

Put another way, law is a reasonable mandate, from a legitimate authority, which is both known and intended for the good of all

There are various kinds of laws that instruct and guide man either in his role as a vehicle driver (traffic law), as a voter (election law), or as a Catholic (canon law), but that law which instructs and governs man simply as man, is the natural law. It is the law, according to Aquinas:

…corresponding to its nature which stipulates the instrumental and constitutive means necessary for perfection (Ibid.).

It is the map toward human perfection, flourishing, or happiness.

It also fulfills each of the above-mentioned requirements for law as such: it is based on human nature (making it reasonable); comes from the author of nature and is discovered by sound reasoning (thus promulgated and by a legitimate authority) as well as intended for the common good.

Thus we have a law, but what are its precepts?

The One Rule

The law guiding man’s nature has essentially only one rule, upon which all the others are based. As Aquinas writes:

Hence this is the first precept of law, that good is to be done and pursued, and evil is to be avoided. All other precepts of the natural law are based upon this…(ST, I-II, Q. 94, A.2).

This is the mandate upon mankind, written into his nature and his means to happiness: do good, and avoid evil. 

Flip on the news, and notice that this precept is never proved or debated, it is merely presumed. However, what is not presumed and is debated is the correct application of it. Aquinas points this out as well:

Consequently we must say that the natural law, as to common first principles, is the same for all…(but not)…as to certain matters of detail, which are conclusions…since in some the reason is perverted by passion, or evil habit, or an evil disposition of nature…(ST, I-II, Q. 94, A.4).

G.K. Chesterton gives us a striking example of both the universal given that one ought to “do good and avoid evil” as well as its possible misapplication, in this statement from one of his classmates, whom he terms “The Diabolist.” Chesterton writes:

He only said, “But shall I not find in evil a life of its own? Granted that for every woman I ruin one of those red sparks will go out…he said, in his tired, fair way. “Only what you call evil I call good” (The Diabolist).

The Diabolist’s comment, “only what you call evil I call good” does not deny the precept to “do good and avoid evil,” it merely fails to identify what is truly good from what is truly evil.

Consequently, since it is possible to mistake good for evil and vice versa, we are right to ask if there is any objective standard by which we can objectively identify what is, in fact, good or evil for us.

Human Nature

The objective, naturally knowable, standard by which we can judge what is in fact good or evil for us to do is human nature. Dr. Feser writes:

Traditional natural law theory grounds morality in general…in human nature. The basic idea is that what is good for a thing is determined by the ends for the sake of which its natural faculties exist (The Role of Nature in Sexual Ethics).

For example, the end or goal of man’s digestive system is, of course, digesting (hence the system’s name). Therefore, an action like eating pennies, since it is objectively bad for its corresponding system, would be bad for the person to do. It would be a voluntary action against one’s humanity.

Note that this would hold true even if someone somehow enjoyed the taste of pennies, or had found a way to make eating pennies pleasurable. Regardless of taste, based on one’s biology, it would still be objectively clear that such an action is wrong.

Thus, for man’s good, natural law proclaims truths such as the cognitive system is for cognition (against drunkenness), and the reproductive system is for reproduction (against contraception and abortion).

Of course, no one need always be reasoning (like when asleep) nor exercising one’s reproductive faculties (in the case of single or consecrated persons). It is rather the intentional misuse or damage of these faculties (as in the penny example) which is prohibited by the natural law.

Law & Life

Neither eating pennies, nor drunkenness, nor contraception make for human flourishing because they are directly against a person’s humanity. Ed Feser, makes the point using reproduction as an example (which is worth quoting at length):

Now, since the natural ends of our sexual capacities are simultaneously procreative and unitive, what is good for human beings vis-à-vis those capacities is to use them only in a way consistent with these ends. 

This is a necessary truth, given the background metaphysics. It cannot possibly be good for us to use them in a way contrary to these ends, whether or not an individual person thinks it is, any more than it can possibly be good for a tree to fail, because of disease or damage, to sink roots into the ground. 

This is true whatever the reason is for someone’s desire to act in a way contrary to the purposes of nature—intellectual error, habituated vice, genetic defect, or whatever—and however strong that desire is. That a desire to act in such a way is very deeply entrenched in a person only shows that his will has become corrupted. 

A clubfoot is still a clubfoot, and thus a defect, even though the person having it is not culpable for this and might not be able to change it. And a desire to do what is bad is still a desire to do what is bad, however difficult it might be for someone to desire otherwise, and whether or not the person is culpable for having a tendency to form these desires. (He may not be.) (Ibid)(paragraph divisions added).

In brief, no matter how limited one’s understanding, or contrary to one’s desires, human happiness is contingent upon living humanly: living according to the natural law.

Law and Eternal Life

As we began, lawlessness begets sadness, as evidenced by the saddest and most morally relativistic generation of the last century. To live happily, we must live humanly, and by adhering to that law which makes both possible.

Yet there is more.

Since universal law presupposes a universal Lawgiver. Natural law leads us to wonder if there might be some other law, one that is supernatural, which may lead us to another kind of life: eternal life.

For more on this, see Just Be a Good Person and Faith vs. Doubt.

1. See Science Alone for a refutation of relativism. Barna Research, Gen-z and Morality: What teens believe (So Far).
2. See Gallup Research, Nearly Half Adults Tried Marijuana and Oberlo Statistics, Digital Media Consumption.
3. Specifically a natural happiness, regarded in abstract apart from supernatural law and happiness.

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