Meaning

(Summa Theologica, I-II, qq. 93, 94.)

Meaning.—The Natural Law is so called for the following reasons: (a) it is received by man, not through special promulgation, but along with his rational nature. Hence, St. Paul says that the Gentiles, who had not received the laws specially promulgated, were a law unto themselves, that is, through their rational nature (Rom., ii. 14); (b) it includes only such precepts as can be known or deduced from the very nature of man, and thus some pagans fulfilled the Law of Moses naturally, i.e., as regards its natural precepts (Rom., ii. 14); (c) it can be known from the natural light of reason without instruction, being a law written on the heart of man (Rom, ii. 15).

The Natural Law is defined theologically as a participation of the Eternal Law in man. Three elements constitute its essence in its integrity: (a) a passive participation of the Eternal Law consisting in man’s nature and faculties with their inclinations to their proper acts and ends. This man shares with all creatures. (b) an active participation in the Eternal Law proper to man. This consists in the activity of man’s intellect through which he shares in God’s providence and government in a special way as one who can rule himself and others. Reason, reflecting upon the natural inclinations and ordering them to their proper acts and ends, formulates (c) a dictate or command of the practical reason. This command constitutes the essence of Natural Law. “Hence the Psalmist after saying (Psalm, IV. 6): Offer up the sacrifice of justice, as though some one asked what the works of justice are, adds: Many say, Who showeth us good things, in answer to which he says: The light of thy countenance, O Lord, is signed upon us. Thus the Psalmist implies that the light of natural reason, whereby we discern what is good and bad, which is the function of the Natural Law, is nothing else than an imprint on us of the divine light. It is therefore evident that the Natural Law is nothing else than the rational creature’s participation in the eternal law” (Summa Theol. I-II, q. 91, a.2).

Relation of the Natural Law to Other Laws.-(a) The Natural Law is inferior to the Eternal Law; for, while the Eternal Law exists in the mind of God, underived from any other law and is regulative of all created things, the Natural Law exists in the mind of man, as a derivation and image of the Eternal Law and a rule for man’s acts only. (b) It is superior to Positive Law, for all Positive Law is a deduction from or a determination of Natural Law.