What the natural law commands

CERTAIN actions are in themselves conformable to right reason, while others are opposed to it. On account of the relation between parent and child, right reason tells us that it becomes a child to show love and reverence toward his parents; on the other hand, hatred and ill-treatment of one’s parents are opposed to right reason. Conscience tells us, moreover, that it is our “ duty’ to love and reverence our parents, that we “‘ ought ” to do so, that we are “‘ bound ” to do so; thereby making known to us the will and precept of a superior, the will and command of God, the Author of nature, and our Lord and Master. He cannot be indifferent as to whether we follow the dictates of right reason or not; he necessarily, as he is good and holy, wills that right order should be observed by us.

The rules of conduct which right reason manifests to us, and conscience, the voice of God, commands us to follow, constitute the natural law, which is a participation in human reason of the eternal law of God, willing that right order should be observed, forbidding it to be disturbed.

The objects, then, of the natural law are all those actions which in themselves are conformable or not conformable to rational human nature. They are actions which are necessarily prescribed, because they are demanded by human nature, or, on the contrary, they are necessarily forbidden, because they are contrary to the demands of human nature. They are good or evil, not merely because they are commanded or forbidden by lawful authority, but because in themselves they are becoming or unbecoming for man to perform because human nature is what it is, This is the ground of the well-known distinction between mala in se and mala quia prohibita.

As rational human nature remains substantially the same, and its essential relations do not change, it follows that the duties which the natural law imposes on man do not change substantially ¹ objectively times. either. The natural law, then, in itself and is universal and unchanging; it binds all men at all However, it does not follow that the natural law is always and everywhere equally well known. In its broad general principles, indeed, it has been known and taught at all times; it would be impossible for human society to continue unless the general principles of the natural law were known and acted on. Any serious departure from the law of nature soon brings with it its own remedy and correction by the stern elimination of the delinquent. Still there may be, and there is, ignorance of particular details and applications of the law of nature, even in matters of importance and of frequent occurrence. This is true not only of savage and untutored races, not only of primitive races, but even of civilized and Christian peoples. Theologians readily admit this. Many theologians of note allow that among such peoples there may exist ignorance of the malice of fornication; they warn us that other acts against the natural law are sometimes done in good faith, without any knowledge of their malice. The presumption, then, is that among Christians the general principles of the law of nature are known, but the confessor must be prepared to meet with cases of ignorance of the particular details and applications of it.

¹ Matt. v 17.

Properties.—Since the Natural Law is the reflection of God’s Eternal Law impressed on the rational nature of man, it has the following properties: (a) it is both declarative and imperative; being immanent in man, it declares to him his duty; being transcendent in its origin, it speaks with the voice of authority; (b) it is universal, or for all, for it declares the necessities of nature, which are the same in all men; (c) it is unchangeable, that is, it admits of neither abrogation, nor dispensation, nor emendatory interpretation, for the essences of things, on which it is based, do not change; (d) it is recognizable and indelible, that is, it cannot fail to be known and cannot be forgotten by mankind, for it is promulgated through the light of reason given to man.

The Natural Law is of universal obligation. It is in force in all places, at all times, and for all persons. (a) Thus, those who have not the use of reason, such as infants and the insane, are subject to the Natural Law on account of their human nature which is injured by any transgression of its inclinations. Their ignorance, of course, excuses them from formal sin (see 24 sqq., 97 sqq.). Example: It is sinful to induce or permit children to blaspheme or become intoxicated, not only because of scandal or of harm done to them, but also because such things are necessarily repugnant to their dignity as human beings. (b) those who have the use of reason are subject to the Natural Law, and their transgressions are imputable as formal sins and incur the debt of punishment.

The Natural Law is unchangeable, not as regards additions, but as regards subtractions. (a) Additions may be made to the Natural Law, for, in many points not determined by it, it is well that supplementary regulations be made to provide for particular situations. These additions, made by Positive Law, divine and human, are amplifications rather than changes, for they must not be out of harmony with Natural Law. (b) Subtractions may not be made from the Natural Law—that is, there can be no exception when it declares that a certain thing must always be observed, and there can be no abrogation when it declares that a certain thing must be observed usually.

From the foregoing it follows that no precept of the Natural Law can be abrogated—that is, repealed and deprived of all force, so that what was today a precept of nature should no longer be such tomorrow; for the necessities of nature on which the Natural Law is based do not change.

As to the question whether any precepts of the Natural Law may be dispensed or not, distinction must be made between two kinds of dispensation.

(a) A dispensation in the strict sense is granted when a legislator relaxes for a particular case the obligation of a law, although the subject-matter of the law still remains. Example: Titus is in the class of those who are bound by the law of fast, but he is exempted by competent authority from the obligation of the law.

(b) A dispensation in the wide sense is granted when the subject-matter of the law is taken away by the legislator himself or by another, so that it ceases to be comprehended under the law, although the obligation of the law still remains. Example: Balbus owed money to Caius, but, as Caius forgave him the debt, he is no longer in the class of those who are bound by law as debtors to Caius; he is not exempted, however, from the obligation of the general law that one must pay one’s debts.

There are various opinions as to the possibility of a dispensation from the Natural Law granted by God, but the following doctrine seems the most probable.

(a) God Himself cannot dispense in any way from those precepts whose matter is necessary (see 302), such as axiomatic precepts (viz., those that prohibit malice and those that command duties to be fulfilled at a proper time and place). For all the subject-matter of these precepts is intrinsically either consonant with or dissonant from right reason. Example: God could not by decree abolish the Ten Commandments, for, as long as God is God, He must remain worthy of worship, praise and love; and, as long as man is man, it must be against his rational nature to murder, steal, lie. etc.

(b) God cannot grant a dispensation in the strict sense from those precepts of the Natural Law whose matter is contingent, such as the precepts against the taking of human life, against taking possessions from others against their will, etc. For, as long as the subject-matter of these precepts remains what it is supposed to be by the law, transgression of them is necessarily opposed to reason. Example: God cannot command the killing of a person who has the right to life, nor the taking of property that rightly belongs to another.

(c) God can grant a dispensation in the wide sense from contingent precepts of the Natural Law—that is, He can make a change as regards the subject-matter, so that it no longer falls under the law. Thus, since God is the supreme Lord of life and property, He can without injury to human rights command that a person be put to death or deprived of his property by another. These acts would not constitute murder (i.e., unjust homicide) or stealing (i.e., unlawful taking); for God has a higher claim on life and possessions than the immediate owners have. Examples: The command to Abraham to kill his son was not a dispensation from the law against murder any more than the sending of death to the first-born of Egypt was the commission of murder by God. The command given the Israelites to carry away with them the goods of the Egyptians was not a dispensation from the law against theft, any more than the destruction of the fruits of the Egyptians by plagues was the commission of theft by God.

Is God able to make a decree which sets up a most grave public necessity opposed to the observance of a law of nature?

(a) If there is question of absolute laws (see 303), this cannot be done, for God cannot deny Himself by making a disposition contrary to His Eternal Law. Example: We do not read that God ever sanctioned polyandry or marriage between parent and child, and it seems that He could never permit such things as lawful.

(b) If there is question of relative laws (see 303), the decree in question can be made by God; for the unbecomingness of that which is forbidden by a relative law passes away in the face of a great need. Example: Since God desired the propagation of the human race from one man and one woman, marriage between brothers and sisters was not against the Natural Law at the beginning. Since God desired the speedy multiplication of the chosen people after the patriarchal era, polygamy was not repugnant to nature among the Jews of that period.

Is God able to remove a natural obligation in a case of private necessity, that is, when the fulfillment would be harmful to an individual?

(a) Natural obligations that do not depend upon any free consent of the will given to them (see 304) cannot be removed except by a dispensation widely so-called and when their matter is contingent (as explained in 309-310). Examples: God could not dispense an individual from the duty of confessing Him in order to escape death, for the subject-matter of the law here is necessary. God, could dispense an individual from the obligation of not taking the property of another, for God is the principal owner of all things, including those possessed by others.

(b) Natural obligations that depend upon the act or deed of human beings consenting to obligation (see 304) can be removed. For since human beings cannot know all the circumstances existent, or all the conditions that will arise, it can happen that a thing agreed to or promised is only seemingly good, or will change from good to bad, so that while the promise or agreement made is in itself good and naturally obligatory, its fulfillment would work harm and evil, or be useless, or would prevent the accomplishment of a greater good. It is reasonable, therefore, that God should release from obligation here, thus changing the subject-matter of the law, so that it is no longer comprehended under the law (see 309-310). Example: Titus vows or swears that he will give a certain alms or make a certain pilgrimage; but, when the time for fulfillment arrives, his circumstances have so changed that it would not be advisable for him to keep the promise made. The Church, acting in the name of God, can declare that the subject-matter of this promise has become harmful and is not longer suitable, and hence that the obligation has ceased.

Human Authority and Modification of the Natural Law.

(a) Additions to the Natural Law may be made, not only by positive laws of God, but also by human laws of Church or State, through the introduction of that which Natural Law permits, or the determination or confirmation of that which Natural Law contains implicitly or explicitly. Examples: Division of property rights introduced by the law of nations; conditions for valid contracts determined by particular codes; the laws against theft and murder confirmed by definite penalties prescribed for those crimes.

(b) Subtractions from Natural Law cannot be made by any human authority, for God has not delegated His power of dispensing which He has as supreme owner of all things. Examples: No human authority could authorize a father to sacrifice his innocent son, nor permit a servant to carry away the effects that belong to his employer.

Apparent Cases of Dispensation from Natural Law made by Human Authority. (a) The Church frees from the obligation of vows, contracts and promissory oaths, from impediments to marriage, from espousals, etc. In so doing, however, she does not dispense from the Natural Law that vows, contracts, etc., should be fulfilled, but only declares in the name of God that the subject-matter of an obligation contracted by act of man’s will has become unsuitable for vow, contract, etc., and hence is no longer comprehended under the law.

(b) Societies or private individuals can free from the obligation of paying or returning to them what they have a right to, as when a creditor forgives a debt, or an owner permits a thief to keep what he stole. In so doing, however, they do not dispense from the law of nature that one should pay one’s debts and not keep ill-gotten goods; they only change the quality of the things in question so that they cease to be due another or ill-gotten, and hence no longer fall under the law. This differs, too, from the dispensation that God can grant; for He can transfer rights without the consent of the immediate owner (see 310).

Interpretation—that is, explanation of the law which indicates whether or not it obliges in a particular case—may be applied to the Natural Law as follows:

(a) Interpretation which explains the intention the lawgiver had in making the law and the sense he gave to the words of the law (verbal interpretation), may be made when either a law itself is not entirely clear, or some person is not clever enough to see its meaning. Example: The commandment, “Thou shalt not kill,” needs to be interpreted, for it does not forbid every kind of killing.

(b) Interpretation which explains the intention a lawgiver would have had, had he foreseen a particular case in which his law would be harmful, and which therefore sets the will of the lawgiver against the words of the law (emendatory interpretation, epieikeia), may not be applied to the Natural Law; for God, unlike human legislators, foresees things not only in general, but also in particular, and hence there is no room for correction or benign interpretation of natural laws. Example: Titus, who was a chronic invalid, committed suicide in order that his family might be freed from distress. He argued that the Fifth Commandment did not foresee the difficulties of earning a living under modern conditions, and that his sacrifice would be pleasing to God. Titus did not reason well, for suicide is forbidden for motives that apply universally (e.g., that society, and especially one’s family, are injured by the act of suicide).

Verbal interpretation of the Natural Law is made as follows: (a) by private authority—that is, by those who are competent, on account of learning and prudence, to understand the meaning of the law, such as moral theologians; (b) by public authority—that is, by those who are appointed to rule, with the prerogative of declaring the meaning of the Natural Law. The Pope, since he must feed the flock of Christ, is divinely constituted to interpret Natural Law, and does so authentically and infallibly. Thus, the Church declares that certain matrimonial impediments are natural, and therefore incapable of being dispensed.

On the competence of the Church to give authoritative interpretations of the natural law in the field of morals, Pius XII has spoken clearly and forcefully: “... it must openly and firmly be held that the power of the Church has never been limited to the boundaries of strictly religious matters’ as they are called; but the whole content of the natural law, its institution, interpretation and application are within its power insofar as its moral element is concerned. For the observation of the natural law, by the ordination of God, is the way by which man must strive to attain his supernatural end. On the road to this supernatural end. it is the Church that is his leader and guide. This is the way the Apostles acted, and from the earliest times the Church held to this way of acting as it does today—and not in the manner of a private leader and counselor, but from the command and authority of God” (AAS 46 [1954] 671-672).

From the foregoing it follows that the Natural Law is so unchangeable that it cannot be abrogated or properly dispensed, or given an emendatory interpretation. But, though the law itself remains, there are cases in which non-observance of it is excused from guilt. These cases can be reduced to physical and moral impossibility.

(a) In cases of physical impossibility (i.e., when the powers requisite for observance are wanting), one is manifestly excused; for law is reasonable, and it is not reasonable to require impossibilities. Examples: Infants are not guilty of sin against the Natural Law, when they do not pray; for they lack the use of reason, which is presupposed by the notion of prayer. He who is unable to work is not obliged to earn support for relatives.

(b) In cases of moral impossibility (i.e., when a law cannot be kept without the infringement of a higher law or the loss of a higher good), one is also excused; for it is unreasonable to prefer the less to the more important. Example: Titus lends a revolver to Balbus. Later he asks that it be returned to him, as he wishes to kill himself. Now, property is less valuable than life, and hence Balbus is unable in this case to observe the law which requires that things borrowed must be returned.

Moral impossibility is also defined as the inability to observe the law without serious injury or loss to oneself or a third party. Serious injuries are such as deprive some one of great goods, such as the use of reason, life, knowledge, friendship, health, reputation, property. Serious losses are such as prevent one from obtaining notable goods, The following rules indicate when grave inconvenience excuses, and when it does not excuse, from the guilt arising from the non-observance of Natural Law:

(a) when the law is negative (i.e., prohibitory), no inconvenience excuses from sin; for that which is forbidden by the Natural Law is always morally evil, and hence more to be shunned than even the greatest physical evil, or death. Example: One is obliged, under grave or light sin, as the case may be, to forfeit all temporal goods rather than blaspheme, murder, lie, etc.;

(b) when the law is affirmative (or mandatory), an inconvenience which, all things considered, is really and relatively grave, excuses from sin; for that which is commanded by the Natural Law is not always morally obligatory, but only at the right time and in the right circumstances (see 371), and hence its omission is not always morally evil. Examples: Sempronius vowed that he would go on foot to a place of pilgrimage, but when the day came he had a sprained ankle that would be badly injured if he walked. Caius received a jewel stolen from Balbus and promised that he would return it at once to the owner, but he finds that he cannot do so now without danger, either of the arrest of himself or of the one who took the jewel. Titus sees a person who has been seriously injured lying by the roadside, but he is tired, and neither gives help himself nor summons aid. In the first two cases the inconvenience is grave, and hence Sempronius may ride to the place of pilgrimage, and Caius may return the jewel to Balbus later; but the inconvenience of Titus is slight, and does not excuse him from sin.

Just as the Natural Law is unchangeable, because based on the unchangeable Eternal Law instituting the nature of man, so is it easily knowable, because it is promulgated by the light of reason. Hence: (a) invincible ignorance of the entire Natural Law is impossible in any person who has the use of reason; (b) complete forgetfulness of the Natural Law by mankind is impossible.

Those who have not the use of reason, either habitually (as children and the insane) or actually (as the intoxicated), may be invincibly ignorant of the Natural Law—for example, they may be unable to perceive even the difference between right and wrong. As to those who have the use of reason, they can be ignorant of the Natural Law only as follows:

(a) they cannot ever be invincibly ignorant of the most general precepts (such as “good is to be done,” “evil is to be avoided”), for since they know the difference between right and wrong, they must also perceive that which is contained in the concepts of right and wrong, viz., that the former is something desirable and which ought to be done, the latter something undesirable which must not be done;

(b) one cannot, as a rule, be invincibly ignorant of those precepts that are immediately inferred as necessary conclusions from the most general precepts (such as “that which was borrowed must be returned”), for the conclusion follows so easily from the manifest principle that only in exceptional cases could one be excused for not knowing its truth;

(c) one can, even as a rule, be ignorant of precepts that are inferred as necessary but very remote conclusions from the most general precepts, (such as “that which was borrowed must be returned at such a time or place, or in such a manner or condition”), for this conclusion is so far removed from its premise, and there are so many factors to be considered, that considerable knowledge and skill in reasoning are required for a correct judgment—things in which many people are lacking.

The Commandments of the Decalogue follow directly from the most general precepts of the Natural Law, and so to them may be applied what was said in the previous paragraph. Hence: (a) generally speaking, no person who has the use of reason can be invincibly ignorant of the Commandments. St. Paul blames the pagans as inexcusable in various sins committed against the Decalogue; (b) in special cases, a person who has the use of reason can be invincibly ignorant of one or more Commandments; for while the Commandments may be easily inferred by most persons from the common principles of right and wrong, there are sometimes involuntary impediments that hinder the right employment of reason. Thus, children and older persons whose mentality is undeveloped, although they know the difference between right and wrong, are frequently unable to draw the conclusion that follows from it (e.g., that one should not tell lies).

The Commandments regarding which invincible ignorance may most easily exist are: (a) those that deal with merely internal acts, for the malice of violating them is less apparent. Hence, many theologians admit that even among Christians the wickedness of sinful thoughts and desires may be inculpably unknown, at least when the wickedness of the corresponding external acts is also not known; (b) those that deal with the control of sensuality, for the impulse to inordinate acts is at times most vehement. Unde theologi sunt qui affirmant malitiam peccatorum externorum contra sextum invincibiliter ignorari posse, non solum apud infideles, sed etiam apud Christianos, ita quod ab adolescentibus facile ad tempus ignorari possit malitia mollitiei.

If a Commandment be applied to some particular case in which there are many circumstances to be considered, or some reason that appears to change the subject-matter of the law, even adults who have the perfect use of reason may be invincibly ignorant; for in such instances we are considering, not an immediate, but a remote conclusion from the general principles of Natural Law.

(a) If the case is difficult relatively (i.e., in view of the training or lack of education of the person studying it), there can be invincible ignorance, at least for a time. Examples: Jepthe, according to St. Jerome, appears to have been invincibly ignorant that it was not lawful for him to slay his daughter. Being a soldier and living in a rude age, he perhaps did not appreciate the sacredness of human life. Unlettered persons might conceivably think in good faith that it is not wrong to commit perjury in order to help one in danger, to steal in order to pay debts, to think evil if there is no intention to fulfill it, to do what the majority do or what is tolerated, etc.

(b) If the case is difficult absolutely (i.e., in view of the matter itself, which is complicated and obscure), there can be invincible ignorance, even for a long time. Thus, it is so difficult to settle many problems pertaining to justice (i.e., to the application of the Seventh Commandment) that we find professional theologians who take opposite sides, or admit that, speculatively speaking, they do not know where the truth lies.

The Natural Law can never be erased from the hearts of men. (a) In abnormal circumstances only, as when the general power of reasoning has been weakened or lost, can the Natural Law be forgotten. Thus, to a degenerate who becomes violently insane murder and other crimes may appear as good acts. But no community could govern itself by the standards of madmen and long survive. (b) In normal circumstances (i.e., as long as the general power of reasoning remains unimpaired), the Natural Law cannot be forgotten, as far as its general principles or immediate conclusions are concerned, although it may be overlooked or lost sight of when it is applied to particular cases, or when remote conclusions are deduced from it.

As long, therefore, as a body of men remain sane, even though they be uncivilized or addicted to crime, they cannot become oblivious of the Natural Law. (a) The general principles (“good is to be done,” “evil is to be avoided”) cannot vanish from the mind, although, in particular affairs, anger, pleasure, or some other passion may prevent men from thinking about them. Thus, when the mob spirit takes hold of a crowd, it becomes intent only on violence or revenge, and gives no thought to conscience. (b) The secondary precepts, such as those contained in the Decalogue, cannot be obliterated from the mind, although in applying them to concrete situations a people may go astray.

There are many examples of laws, both ancient and modern, which permitted or commanded, for particular cases, things contrary to the current application of natural precepts. Thus, the Spartans and the Romans ordered the murder of infants who were weakly and of slaves whose master had been killed. Some ancient races encouraged robberies committed beyond the boundaries of the states, and savage tribes have been found who had the practice of putting to death parents who were aged or infirm.

The causes of wrong applications of the Natural Law are the following:

(a) Some causes are involuntary. Thus, the correct application may be difficult, as when more than one moral principle has to be considered and applied; or, if the case is not difficult, the person who makes the application may be mentally undeveloped, or his mind may be blinded on account of his bad education or environment. Examples: The races who saw no infamy in robbery committed against their neighbors, lived in a wild age when such acts of violence seemed necessary as measures of self-protection. The savage killed his aged parents, because to his untutored mind this seemed an act of mercy.

(b) Some causes are voluntary, such as neglect of the truth, vicious habits, etc. Examples: St. Paul blames the pagans for their idolatry, because they had darkened their own minds about God. Pirates and bandits who came to regard violence as necessary for their own defense were responsible for their state of mind, inasmuch as they had chosen a life of crime.

Transgression of Natural Law, therefore, is not imputable as formal sin if it is not voluntary. Hence: (a) lack of knowledge excuses, when ignorance is involuntary (e.g., those who have not the use of reason, as infants and the unconscious; children and others mentally undeveloped who cannot grasp the meaning of some precept; educated persons who are unable to get a right solution of some knotty problem of morals, etc.); (b) lack of consent excuses in whole or in part (as when one acts through fear).

91. Principles. - I. Every man is born and remains subject to natural law. For since natural law is the divine will itself prescribing things consonant with right reason, it is imprinted on the mind of every man with an indelible character. Therefore it happens per accidens ¹ that, reason being enveloped, it is not immediately recognized, or sometimes ceases to be known.

¹ These things must be said thus, because man is never considered exempt from natural law, but is only excused from guilt when, in violating it, the perfection of the act is lacking. Hence it also follows that he whose use of reason is impeded cannot be impelled to acts opposed to natural law; which happens otherwise if the discussion is of merely human laws.

II. All and only subjects habitually possessed of reason are subject to human law. - The reason for the first is that law cannot be made except for subjects. The reason for the second is that men habitually lacking the use of reason cannot be directed by laws.

III. Only men actually using reason can morally violate law; because, cognition being lacking, no one can sin, according to the things said in the Treatise on Human Acts, no. 4. - Hence those who lack reason for a brief time are said to be excused from fulfillment of the law, although they are subject to it.

221. In a general way the natural law embraces those things which are so fitting or repugnant to rational nature that they ought to be commanded or prohibited by the Author of nature.

(A) Now, with respect to the logical nexus by which they are connected with one another, the precepts of the natural law are of three kinds: -

(a) Some indeed are most universal, so that the rest flow from them; such are these and similar ones: good is to be pursued and evil avoided; the supreme good is to be loved; what you do not wish to be done to you, do not do to another; live conformably to right reason.

222. Among philosophers and theologians it is asked what is the supreme principle from which the rest flow logically. St. Thomas asserts that it is this: good is to be done and evil avoided.¹ According to others: Live conformably to human nature, considered according to all its essential relations.² Berti proposes this, according to the mind of St. Augustine: Love God as the end and the rest on account of Him.³ Others prefer this formula: Exhibit also by free actions the image of God, absolutely holy, impressed upon you by way of rational nature.⁴ Meyer proposes this: Preserve the right order of rational nature as divinely holy.¹

¹ St. Thomas, Ia IIae, q. 94, a. 2.

² Thus not a few Scholastics.

³ Berti, Theolog. discipl., lib. XX, c. 4, prop. 3.

⁴ Carl Aeger, Moralphilosophie, 1873, S. c. 63 ff.

¹ Meyer, op. cit., n. 284.

Of these, the formula of St. Thomas is the simplest and most clearly intelligible; the last, although not so clearly intelligible, seems more complete and scientific; the Augustinian one is in itself most perfect, but in the order of knowledge it is not first, nor explicitly known to all. In any case all agree substantially as to the sense.

223. (b) In the second place come those precepts which are deduced from universal principles by an immediate and easy discourse; for example, honor your father and mother, you shall not steal, you shall not kill, and the rest contained in the Decalogue, if one excepts the sanctification of the Sabbath day, which is a positive law.

(c) In the third place proceed those precepts which are deduced from the first principles remotely and only by diligent study and more difficult discourse; for example, an injury inflicted on someone, in a well-ordered society, is not to be avenged by one's own authority. Since precepts of this kind are not easily known by all, they are often proposed more clearly and certainly by positive law.

224. (B) With respect to necessity, the precepts of the natural law are some primary and others secondary: the former are so necessary for the particular or social good that, without them, the moral order is impossible; thus blasphemy, the unjust killing of an innocent man, false testimony, etc., are opposed to primary natural right. - But secondary precepts are those which are very useful for the particular or social good, but not necessary, so that the moral order can subsist without them, although less perfectly; thus polygamy and divorce are opposed to secondary natural right.

225. (C) By reason of the object about which they are concerned, natural precepts regard: (a) God, who is to be worshiped and loved; (b) our neighbor, to whom reverence, justice, and charity are owed; (c) ourselves, insofar as we ought to subject the sensitive faculties to reason, and reason to God.

226. The natural law is universal, immutable, and non-dispensable; the reason is because it flows not from the positive will of God, but from the very nature of things. This, however, needs declaration.

(A) The natural law is universal, insofar as it binds all those who enjoy the use of reason; for, on the one hand, it is promulgated in the conscience of each rational being, and on the other it is enacted for every rational creature.

It is asked, however, whether it also reaches infants and the insane. The controversy had concerning this matter can be reconciled in this way: the natural law of itself affects them, insofar as they are radically and potentially rational; but it does not oblige them morally, under penalty of sin:¹ for only those are capable of moral obligation and imputability who enjoy the use of reason.

¹ Adults, however, using reason, sin when they impel them to act against the natural law.

227. (B) The natural law is immutable, in the sense that it cannot be changed in itself, although it admits some changes in its application.

(a) Indeed, it cannot be changed in itself: for it is founded in the very nature of the rational being, considered in its relations with the ultimate end; but the nature of things and their relations to the ultimate end always remain the same. - Yet in order rightly to understand immutability of this kind, we must consider the natural law not in some abstract and insufficiently determined principle, but with all the adjuncts which constitute morality. Thus homicide is prohibited by natural right, and nevertheless there are many cases in which it is licit to kill others. But to one attending even a little, it is clear that not every homicide is prohibited, but only unjust killing, or the killing of an innocent man by private authority, without necessity; consequently, when an unjust aggressor is killed, or a criminal is condemned to death, the natural law is not changed, since it in no way prohibits the legitimate defense of oneself or of society: the circumstances, the adjuncts, are changed; the law itself remains the same.

This is true also of secondary precepts; take, for example, polygamy, which is opposed to secondary natural right, and yet flourished among some Patriarchs; the law itself suffered no change in itself; for at every time it was contrary to the secondary ends of marriage, especially to the peace of families; but, since it did not hinder the primary end of marriage, namely the procreation and education of offspring, it could be permitted or tolerated, with means employed by which abuses would be prevented.¹

¹ Some older scholastics wrote that the natural law can be changed as to the more remote conclusions; they bring the example of a deposit, which by natural right ought to be returned, and nevertheless sometimes cannot be returned, because, for example, it is foreseen that the owner will use the deposited sword to kill an enemy. - But in a case of this kind there is no change of the natural law; for the law does not establish that a deposit is to be returned in every case, but forbids it to be returned at that time when the owner is going to abuse his own thing.

(b) But in its application it suffers some changes, when secondary precepts are in question. Thus God tolerated, under certain conditions, polygamy and divorce; for in those things which are not absolutely necessary, but only very useful, it can happen that, circumstances having changed, the application of the law, even if very useful, is not urged; for example, among the Jews divorce was tolerated, in order to avoid worse abuses, namely adultery or the killing of a spouse; but divorce of itself remained contrary to the perfect equality of the contract, to the best education of offspring, to the peace of families, etc.

228. (C) The natural law is not properly dispensable; and indeed, if God Himself does not change the natural law, no one on earth, not even the vicar of Christ himself, can dispense in this law.² The Church, however, can declare and interpret it, and that infallibly; for she received from Christ the power of teaching, and consequently of explaining and interpreting divine laws, by defining whether in these or those adjuncts they truly oblige. Thus the indissolubility of marriage pertains to secondary natural right; but the Church, by long-standing practice, has implicitly declared that this indissolubility does not belong to a marriage simply ratified.

² Likewise some older theologians said that some dispensation can be admitted in secondary natural law; they bring the example of the permission given to the Hebrews to carry off the goods of the Egyptians; but from this nothing can be inferred as to the thesis set forth: for since God is the supreme lord of all goods, He could transfer the ownership of certain goods from the Egyptians to the Hebrews, on account of the reason of the public good, or by way of compensation for the labors furnished.

St. Thomas, I-II, q. 91, a. 2 and q. 94, a. 1.

245. Thesis. The participation of eternal law in the rational creature is true law. - For it is:

1. an ordination of reason: the rational creature participates in law intellectually and rationally, and therefore the participation of eternal law in it is properly called law, because it is something of reason: a dictate constituted by reason; in other creatures it is not participated rationally, whence in them a proper inclination is not called law except by similitude;

2. promulgated by God to a community: for although promulgation is made in individuals, by the impression of reason, nevertheless it is made by reason not indeed as it is particular, but as it is common and the same in all, proceeding from the author of nature;

3. it is made for moral honesty, not of one person, but of the whole of humanity.

1. "The common voice of the whole of nature, or rather of its author, who, although He speaks to individuals, speaks as a public person, because He speaks as author of nature itself." Suarez, De Legibus, l. I, c. II, n. 4.

246. Essence of natural law. - Natural law is not law insofar as it is in the legislator as in the one regulating, and accordingly it is not eternal law itself; but it is law as it is in subjects as in those regulated, and accordingly it is the participation, manifestation, passive promulgation of eternal law in us.

And indeed:

1. It is not the will of God, whether necessary or free: for actions are not good or evil because they are commanded or prohibited by the willing God, but they are commanded or prohibited as intrinsically good or evil in themselves; and indeed good things which are required as necessary by order cannot fail to be commanded, and evil things cannot fail to be prohibited. Whence, if per impossible God did not will natural law, nevertheless it would become known to us and obligate us in the same way, because human nature would be constituted in the same way by commanding divine reason, and it, as also our acts, would be ordered to the ultimate end. Law, namely, essentially is an ordination of reason, not of will.

2. The Nominalists, such as Ockham, Pierre d'Ailly, Gerson; likewise Descartes and Pufendorf, say: the free will of God. Suarez speaks in the same way. Liberatore, De Bie, and Gutberlet say: necessary will; Meyer: hypothetically necessary will. Cathrein says: will, without further determination.

3. Billuart notes, diss. 1, a. 1: "For law it suffices that it be directive of human actions, and that it have the power of obligating. But eternal law (as to necessary precepts) and natural law have these two independently of every act of will. Concerning the first there is no doubt; concerning the second it is also clear, because, by the very fact that the reason of the divine mind dictates and intimates that God is to be worshiped, parents are to be honored, etc., and that theft, lying, etc. are evil and therefore to be avoided, there arises in man an obligation to do those things in their time and to avoid these things, even if, per impossible, there were no will obligating to these, because from their intrinsic things or from their nature they are either to be done or to be avoided, by the very fact that through the dictate of reason they are intimated as such."

2. Nor does the will or power of God necessarily seem to have to be attended to in order that natural law become known. For moral necessity or obligation is the absolute necessity of a means to an absolutely necessary end (Q. D. De Veritate 17, a. 3), so that the means is necessary not only under the condition, if someone wills the end, but absolutely, because the end also is absolutely necessary and altogether imposed upon us. Whence, in order to know law or obligation, it suffices that there be present the absolute necessity of an end which is altogether imposed, and that the necessary connection of means to the end be known, and consequently the obligation to those means. Now the end is imposed upon us by the physical necessity of nature: the highest good of rational nature and highest happiness, so that we cannot fail to will it; and reason a) can know that certain particular goods fitting to rational nature pertain to that end (as a necessary condition of true perfection and ultimate happiness), while certain others do not pertain to it, and b) thus can perceive the necessary connection of certain acts, as means, with that end. Therefore the absolute moral necessity of means and obligation arising from nature, or natural law, can be known while abstracting from God, namely, without attending to the will or authority of God. This nevertheless does not exclude that natural law remotely and ultimately depends upon God, and that obligation, once God is known, is perceived more fully and perfectly.

1. Thus Vasquez, Gerdil, D'Hulst, Mercier (in an autograph course of moral philosophy); Manuel de philosophie neo-scolastique (of the Louvain school); Gillet, Du Fondement intellectuel de la Morale d'apres Aristote; Lottin, Le Probleme des Fins en morale, p. 164; Loi Naturelle et positive, p. 20; L'Ordre moral et l'ordre logique, p. 331; Du Rousseaux, Philosophie morale, p. 200 and 227; Garrigou-Lagrange, Dieu, p. 309; Fonsegrive in Revue de Philosophie, 1910; Vie diocesaine, 1923, p. 383; Collectanea Mechliniensia, 1928, p. 330.

3. Yet it is not the categorical imperative of autonomous reason or will (Kant and the Rationalists). For autonomy cannot be reconciled with the idea of true obligation, because human reason cannot obligate itself. Whence obligation is not constituted by human reason, but is imposed from the necessary inclination of our nature, which cannot be changed by us and which always persists immutable. Furthermore, this opinion rests upon the false foundation that man is an end to himself, or an end in himself (cf. Syllabus, prop. 3 and 50), while nevertheless he is essentially a creature of God, depending upon Him and ordered to Him. The ultimate end, namely, is not constituted by reason but by the author of nature.

Therefore, considered in first act, natural law is the habitual inclination of rational nature to its own acts, namely, to knowing and desiring the end or perfect good, and the means necessarily leading to it, or honorable acts to be chosen; whence nature truly is a law to itself, in this sense, that from the necessary and ineluctable inclination of nature to the end there arises obligation to employ the means. In other words, natural law is the light of natural reason by which we are able to discern what is good to be done or evil to be avoided; this light shows goodness and malice and is the rule of our acts, insofar as it is derived from the divine light and is an impression of the divine light in us. Considered in second act, law is the actual dictate or judgment of reason prescribing in a general mode what is good to be done, what evil is to be avoided. Hence:

a) although natural law is not a habit, since it is not that by which reason acts, but that which it dictates, nevertheless the precepts of the law of nature are not always actually considered by reason, and then they are in it habitually, and thus natural law can be called a habit, because it is held by habit;

b) it differs from synderesis, which is not the innate light of reason or its actual dictate, but is a habit (or facility, not strictly innate but flowing spontaneously from the intellect) by which we easily enunciate not all but the first moral principles; whence it contains these principles virtually;

c) it differs from conscience, which is not a general norm of acting but a judgment concerning things to be done in particular.

247. Foundation of natural law. - One must ask not only about the essence, but also about the foundation of natural law or natural obligation, and consequently of every obligation; for positive obligation is founded upon the obligation of natural law, insofar as this commands that superiors are to be obeyed.

Now from what has been said it is clear:

1. That the sole, sufficient, or ultimate foundation is not the will of God, whether free or necessary: not free, because the question is of necessary law; not necessary, because it depends upon something prior from which it has necessity, namely, upon divine wisdom and essence (Q. D. De Veritate 23, a. 6); and therefore it is not the ultimate, sole, and sufficient foundation. Adversaries indeed say that no law is given without a legislator, and that no precept can be conceived without the will and authority of one prescribing. But:

a) this is true of positive law, which is not necessary, not of natural law, whose obligation arises from the nature of things and from the necessary tendency of our nature to the end;

b) besides, by saying that natural law is obligatory because reason dictates that the will of God prescribing is to be obeyed, they will with difficulty free themselves from contradiction, because the said principle, as prescribed by reason alone, is known as obligatory and does not ultimately depend on knowledge of the will of God; otherwise there would be a vicious circle;

c) finally, the first principles of natural law, for example, good is to be done, etc., are known before knowledge of God, just as the knowledge itself of the terms of which they consist and by which, once known, they are immediately enunciated, precedes this knowledge. Whence, although God in the ontological order is the necessary foundation of natural law, He is not so in the logical order of knowledge.

1. Cf. I-II, q. 94, a. 2 and 4; q. 58, a. 5; II-II, q. 47, a. 6; Q. D. De Veritate 16, a. 1 and 2.

2. Nor is the foundation human reason alone, because just as an effect depends more upon the first cause than upon the second cause, so obligation depends more upon the author of nature and eternal law than upon nature and human reason participated from God: for the essential order of things is not from reason nor from itself, but is derived from eternal law.

The foundation seems to be distinguished as twofold:

a) One secondary and proximate: human nature itself regarded completely with its essential and necessary relations, or its ultimate end absolutely imposed upon it, or the essential order of things according to which certain things have a necessary connection with the ultimate end; and this is sufficient for conceiving true and properly so-called natural obligation, as we have said.

b) The other primary, remote, and ultimate: the intellect of God itself, or eternal law with its root, the divine essence. For eternal law is the fountain of human nature and reason, and this is not the rule of our acts except from divine reason, of which it is also a participation. In the same way the foundation of the principles of speculative reason and of eternal truths is twofold: namely, the proximate foundation, the nature of things and the relations which hold among them (which suffices for conceiving necessary truths), and the ultimate foundation, which is the essence and intellect of God. And just as we are able to know the truth of the first principles of speculative reason from the proximate foundation alone, the nature of things, without knowing their ultimate foundation, the divine intellect, so we are able to know the truth and obligation of the first principles of practical reason without knowing their ultimate foundation: the divine intellect and eternal law.

248. Corollary: the system of secular morality, or, as they say, of obligation independent of God, must therefore be refuted, by saying that it is:

1. Here we consider the system under the respect of obligation; above we spoke of it under the respect of morality itself, n. 134.

a) essentially incomplete, since it is silent about God the true ultimate end and about our duties toward God;

b) false, insofar as it affirms natural law to be founded in nature or reason alone, eternal law of God being excluded;

c) ineffective, because law lacks sufficient sanction, and accordingly, the propensities of men to vices being considered, in fact they will not sufficiently observe it.

Yet it does not seem that it should be called contradictory, as if it were impossible to conceive natural law while abstracting from God the legislator, or obligation without God willing and commanding: for that is to say too much, and does not seem true.

But if it is said that obligation cannot be conceived unless the ultimate end to be attained is known, regarded in the concrete, which is God, we think this necessary only for complete knowledge of the whole moral law. For partial knowledge, knowledge of the end considered in the abstract suffices, insofar as it is the supreme and complete good of rational nature. But even granting this, God would not yet have to be regarded as supreme legislator or as commanding by will, but only as the Supreme Good to be pursued.

249. Observation. - Therefore eternal law and natural law differ:

1. subjectively: the former is in God, the latter in the created mind; and therefore

2. materially in physical being: the former is divine wisdom (and essence), the latter is the created light of reason participated from it; and consequently

3. in knowability: the former in itself is known by God alone and by the blessed, the latter is perceived by the light of reason.

Natural law, according to St. Thomas, is "the participation of the eternal law in the rational creature." If you unfold this definition a little, you will be able to say that natural law is a necessary divine command, manifested by natural light, commanding that right order be preserved, forbidding that it be disturbed. - For there exist essential relations of man to God, to himself, and to his neighbor; the complex of these constitutes the essential order, to the preserving of which God cannot not oblige the rational creature, because otherwise He would contradict Himself. Wherefore the author of natural law is God; the subject is the rational creature; the herald is the light of reason; the object, insofar as the law is prohibiting, is intrinsically evil actions, or actions which directly overthrow those relations; but insofar as it is commanding, the object is intrinsically good actions. The former, however, fall under precept at individual moments; the latter only then when, if they were not placed, that essential order would be violated. - Cf. St. Thomas, 1-2, q. 91, art. 2.

Of the precepts of Natural Law, some are more simple and of wider extension; others are derivative, complex, and extend to fewer cases. It is a question of more and less, and no hard and fast line of demarcation can be drawn between them. The former however are called primary, the latter secondary precepts. Again, the nature of man is the same in all men and at all periods of history for its essential elements, but admits of wide, accidental variation and declension for the worse. Thirdly, it is clear that Natural Law is a law good and suitable for human nature to observe. Starting from these three axioms, we apply the reasoning of St. Thomas, 1a 2æ, q. 96, art. 2, not to human law alone, of which he is speaking, but to sundry secondary precepts of Natural Law. These are his words:

"A law is laid down as a rule or measure of human acts. Now a measure ought to be homogeneous with the thing measured. Hence laws also must be imposed upon men according to their condition. As Isidore says: 'A law ought to be possible both according to nature and according to the custom of the country.' Now the power or faculty of action proceeds from interior habit or disposition. The same thing is not possible to him who has no habit of virtue, that is possible to a virtuous man; as the same thing is not possible to a boy and to a grown man, and therefore the same rule is not laid down for children as for adults. Many things are allowed to children, that in adults are visited with legal punishment or with blame, and in like manner many things must be allowed to men not perfect in virtue, which would be intolerable in virtuous men."

This reasoning leads us up to a conclusion, which St. Thomas states thus (la 2æ, q. 94. art. 5):

"A conceivable way in which the Natural Law might be changed is the way of subtraction, that something should cease to be of the Natural Law that was of it before. Understanding change in this sense, the Natural Law is absolutely immutable in its first principles; but as to secondary precepts, which are certain detailed conclusions closely related to the first principles, the Natural Law is not so changed as that its dictate is not right in most cases steadily to abide by; it may however be changed in some particular case, and in rare instances, through some special causes impeding the observance of these secondary precepts."

The reason for this conclusion, more pregnant, it may be, than St. Thomas himself discerned, is given briefly as follows (2a 2æ, q. 57, art. 2, ad 1):

"Human nature is changeable; and therefore what is natural to man may sometimes fail to hold good."

The precepts of Natural Law that fail to be applicable when human nature sinks below par, are only secondary precepts, and few even of them. Christianity brings human nature up to par, and fulfils the Natural Law (St. Matt. v. 17), enjoining the observance of it in its integrity. This is the meaning of St. John Chrysostom's saying: "Of old not such an ample measure of virtue was proposed to us; … but since the coming of Christ the way has been made much narrower." (De Virginitate, c. 44: cf. his 17th Homily on St. Matt. v. 37; indeed the doctrine is familiar in his pages.) Thus the prohibition of polygamy, being a secondary precept of the natural law, failed in its application in that age of lapsed humanity, when a woman was better one of many wives, protected by one husband, than exposed to promiscuous violence and lust. (Isaias iv. i.)