Article — Prümmer, Manuale Theologiae Moralis
Article I. On the Eternal Law
148. Existence. Already the ancient pagans spoke of the eternal law, insofar as they knew that the world was made by the gods.1 Especially Cicero2 proclaimed the eternal law with great eloquence, saying: "This, therefore, I see to have been the opinion of the wisest men, that law is neither a thing devised by the genius of men, nor some decree of peoples, but something eternal, which would rule the whole world by the wisdom of commanding and forbidding. Thus they said that that first and last law was the mind of God commanding or forbidding all things by reason; from which that law which the gods gave to the human race is rightly praised.... Therefore true and chief law, apt for commanding and forbidding, is the right reason of supreme Jove." - But all Christians, who believe in one God, creator and governor of the whole world, must consequently admit the eternal law, which is nothing else than the reason of the government of the whole world existing in the divine mind. Among the Holy Fathers St. Augustine3 stands out, treating this matter in many places and almost following the footsteps of Cicero. - On the contrary, all who deny one personal God, creator and governor of the whole world, such as Atheists, Pantheists, Materialists, Monists, etc., utterly reject the eternal law as a true moral law.
1 Cf. many testimonies brought forward by Ernst Seydl, Das ewige Gesetz in seiner Bedeutung für die physische und sittliche Weltordnung (Vienna 1902).
2 De leg. l. 2, c. 4, § 8.
3 De ordine 2, 4, 11; De libero arb. 1, 6, 15; De civ. Dei 19, 12-13; Contra Faustum 22, 27.
149. Essence. Commonly two definitions of the eternal law are adduced: one of St. Augustine, the other of St. Thomas. The Augustinian definition is this: "The eternal law is the divine reason or will of God commanding the natural order to be preserved, forbidding it to be disturbed."4 Suarez5 rightly notes that in this definition the word "or" is taken for "and." The Thomistic definition is this:6 "The eternal law ... is the reason7 of divine wisdom, according as it is directive of all acts and motions." - Before God made the world, He had the most perfect idea of the whole order of all creatures. He established that order, and all things whatsoever that have been created in time are subject to this order, which is a most beautiful pre-established harmony. Material and irrational beings, for example, stars, plants, animals, etc., necessarily execute this established order; but rational beings, such as man and angel, freely perform those things which the eternal law has established. The Angelic Doctor writes to the point:8 "There is a twofold mode by which something is subject to the eternal law: in one mode insofar as the eternal law is participated by way of cognition; in another mode by way of action and passion, insofar as it is participated by way of an interior motive principle. And in this second mode irrational creatures are subject to the eternal law. Rational nature ... according to each mode is subject to the eternal law: because it both has in some way a notion of the eternal law and again [because] in every rational creature there is a natural inclination to that which is consonant with the eternal law." From these words it follows that the eternal law comprehends both the physical and the moral order of the world; but it more principally touches the moral order, both natural and supernatural.
From these things said it is easily understood how the eternal law, the divine idea, and divine providence (which are really the same in God as being most simple and free from every composition) are distinguished according to our mode of conceiving.
The divine idea is the concept of all created beings, indeed also of possible beings, existing in the divine mind. For just as an architect makes a drawing (commonly, a Plan) before he builds a house, so God freely chose some idea from many, according to which He would construct the whole world. The divine ideas are many; the eternal law is one.
The eternal law is the reason of the government of all beings to the end proposed by God, namely, to the glory of God (Weltregierungsplan).
Divine providence is the execution of the eternal law in individual creatures. Hence St. Thomas9 says: "In God the eternal law is not providence, but as it were the principle of providence; and hence also the act of providence is fittingly attributed to the eternal law."
The eternal law is law properly so called,10 since the definition given concerning law belongs to it in a perfect mode. For it is an ordinance of divine reason for the good of the whole universe, by Him who has care of the community, namely, by God Himself, promulgated. The promulgation of the eternal law indeed was not present from all eternity (except in the divine Word), since then creatures did not exist except in the divine mind alone; but actual promulgation is not of the essence of law.11 Moreover, it seems that even in the eternal law sufficient promulgation was present. For promulgation is necessary for inducing the obligation of law. But from eternity God determined through the eternal law all obligations by which creatures in future time would be bound, nor has any change of these obligations ever come, since God is wholly immutable.12
4 Contra Faustum l. c. (Migne, Patr. lat. 42, 418).
5 De leg. l. 2, c. 6, n. 13.
6 S. theol. I-II, q. 93, a. 1.
7 Reason is the same as: Plan.
8 S. theol. I-II, q. 93, a. 6.
9 De verit. q. 5, a. 1 ad 6; cf. Contra Gent. III, 97, 115, 121.
10 That the eternal law is not law properly so called is taught by St. Alphonsus (Theol. mor. I, de conscientia 75), Cl. Marc-Raus (Instit. Alphons. I, 116), and others.
11 Cf. S. theol. I-II, q. 90, a. 4.
12 Ibid. q. 91, a. 1 ad 2.
150. Derivation of All Other Laws from the Eternal Law. St. Augustine13 rightly says: "There is nothing just and legitimate which men have not derived for themselves from the eternal law." But all other laws must be derived from the eternal law in a threefold way:
1. As from an exemplary cause. For no law is just and right unless it is conformable to the eternal law, that is, to the order constituted by the eternal law.
2. As from an efficient cause. For by God's ordination legislative power has been constituted among men. Wherefore it is said:14 "By me kings reign, and lawgivers decree just things."
3. As from a directing cause. For the eternal law, known by means of faith or even reason, directs legislators, so that they may see what and what sort of laws are to be established according to the diversity of times, places, and persons.15
13 Sermon 81, n. 2 (Migne, Patr. lat. 38, 400).
14 Prov. 8:15.
15 S. theol. I-II, q. 93, a. 3.