The Natural Law

As we have seen, the natural law is the eternal law asknowable by sound human reason without the aid of supernatural revelation. The natural law becomes naturally known (and is thus promulgated) to normal human beings as they advance from infancy to fuller and fuller use of reason. The natural law isnot, in itself, a habit in the human mind, but it tends to become a habit. The habitual knowledge of first moral principles(summed up in: “Do good-avoid evil”) becomes a true habit in the human mind; it is a habit called by the name synderesis.

The basic precept of the natural law, “Dogood-avoid evil,” is the root out of which definite preceptsand prohibitions grow as a person advances in awareness of things and recognizes their good or their evil. The natural law embraces all these directives.

The natural law indicates and directs man’sinclination to act in accordance with reason. Hence, since all virtues accord with reason, we may say that all virtues are prescribed by the natural law.

The natural law is one and the same for all men. Yet,in certain persons, it may be perverted by passion, habit, or evildisposition, as, for instance, in ancient Sparta where lies andthefts and successful trickery were not considered wrong. Now, such exceptions only prove the rule. Such exceptions do not destroy theuniversality of the natural law anymore than the prevalence of malaria among a certain people destroys the universal understanding of what is meant by human health.

The natural law is changeless in the sense that itsprecepts cannot be upset or destroyed. It can change by extension,by new applications, as experience brings new situations and circumstances. Such a change is not in the natural law itself; itis extrinsic to the natural law; it is merely a new use of the natural law. For instance, the question may arise as to the use of atom bombs in warfare; we may inquire whether the use of such weapons is in conflict with the natural law. Such a question is new; it could not arise in the days when atom bombs were entirely unknown. The question seeks to apply the unchanging natural law ina changing world.

The basic and general principles of the natural law cannot be eradicated from human nature. St. Augustine (Conf.ii) says, “The law is written in the hearts of men;iniquity itself does not efface it.”