Summa Theologiae Moralis, vol. I: De Principiis

S. Th. I-II, q. 88, a. 1; q. 72, a. 5; De Malo q. 7, a. 1 and 2.

530. Thesis. There are in fact mortal sins distinct from venial. — It is de fide from universal preaching, confirmed in the Council of Lyon II, profession of faith of Mich. Palaeologus, by Benedict XII const. Benedictus Deus, by the Council of Florence, in the decree of union, and by Trent, sess. 6, c. 5 and 15, can. 23, 25 and 27, and sess. 14, c. 1 and 5, can. 7.

Mortal and venial sin differ in many ways:

1°) as to the liability to punishment: for mortal deserves eternal punishment, but venial temporal punishment. True, says S. Thomas (de Malo q. 7, a. 1), « this difference follows the notion of mortal and venial sin, but does not constitute it. For sin is not such because such punishment is due to it, but rather conversely because sin is such, therefore such punishment is due to it »;

2°) as to the effect, for mortal sin deprives of grace which is the supernatural life of the soul, and therefore it is of itself irreparable and is called mortal (with grace the connected gifts are simultaneously taken away: charity, infused moral virtues, gifts of the Holy Spirit, sacramental graces; likewise the right to heaven and the merits of good works); but venial does not take away (nor diminish) grace which is the principle of pardon and forgiveness, and therefore it is of itself reparable and is called venial¹. But neither is this the constitutive difference: for from this, that some sin is grave, as effect it has the privation of grace and is irreparable, and not conversely. Whence 3°) in the very notion of inordination is to be sought the fundamental and intrinsically constitutive difference. For inordination is twofold: « One by subtraction of the principle of order; another by which, the principle of order being preserved, inordination is made about those things which are after the principle.... The principle of all order in moral matters is the last end... Whence when the soul is disordered by sin about the last end itself, up to aversion from God to whom it is united by charity, it is mortal sin »; when however without aversion from the end, inordination is made only about those things which are to the end, then it is venial sin (q. 72, a. 5). In other words: in mortal [sin] man sets up for himself a last end opposed to God, and turns away from God and averts himself from him (against the order of the end); in venial he inordinately adheres to those things which are to the end, and by this act only does not tend to God (outside the order of the end). From this difference, as from a root, the two former follow.

531. Mortal and venial sin differ on the part of the formal element or privation. — For in both there is an undue conversion to a created good which cannot be referred to the last end, and according to this they can belong to the same species (e.g. theft). In mortal however man is so converted to the created good as if it were his total last end, whence to the conversion is joined the privation of every order to God as to the end, and this privation is aversion or withdrawal from God; on the contrary in venial man is converted to the creature, not as to the last end, but performs some act by which he cannot tend to God, and therefore to the conversion is joined only the privation of actual tendency to God, although the habitual order to Him remains, and this privation is only a retardation or removal from the end. Whence on the part of privation mortal and venial differ infinitely and in the whole genus, for, as S. Thomas says (q. 87, a. 5, ad 1), « the last end differs infinitely from those things which are to the end ».

In other words, in both there is an act tending to something prohibited by law, but the deformity with the law is very different. For law primarily prescribes the very essence of the moral order,

or the very order of subjection to God the last end, secondarily (as complement of order) it prescribes the manner by which this may be done, namely that nothing be done except for this end. Whence something can be against the law in two ways: 1°) simply and perfectly, because it averts from God the supreme good and destroys the essence of the moral order, the very subjection to the last end, and in this way mortal [sin] is against the law; 2°) imperfectly and in a qualified sense, because although it does not contain aversion from the last end, nevertheless it is not referable to the last end God to whom we and all our actions are bound to refer: in this latter way venial sin is against the law; but because it is not against the law of subjection to God but against only the manner which the law intends, it is better said to be beside the law. In mortal therefore there is deformity with the essential and primary ordination of the law prescribing what is altogether necessary to the end, and therefore it is called against the law, i.e. against the end of the law which is charity by which we are subject and united to God; in venial there is only deformity with the accidental and secondary ordination of the law which prescribes something useful for the end, and therefore it is called beside the law, i.e. beside the end of the law, but against only the means to the end, without overturning the subjection to the end. And therefore the notion of sin is analogous (ad 1).

532. Hence the revealed and theological doctrine is understood, about the nature of mortal sin:

A. In Scripture: 1°) Christ himself teaches that there are sins absolutely grave, which are the cause of grave punishment and indeed of eternal damnation: « He who says to his brother: fool, shall be liable to the hell of fire » (Mt. V, 22); « Depart from me, cursed, into the eternal fire » (Mt. XXV, 41-42). Whence also the Apostles affirm that certain sins exclude from the kingdom of heaven (I Cor. VI, 9-10; Gal. V, 19-21; Rom. VI, 23; VIII, 13; James I, 15) and deprive the soul of supernatural light and the life of divine love (John III, 20; I John II, 9; III, 14).

2°) There are nevertheless sins relatively more grave one than another: « He who betrayed me to you has the greater sin » (John XIX, 11; cf. Jer. VII, 26); indeed some so grave that by their nature and as it were without a miracle of God they are said to be « unremissible » (Mt. XII, 31; Mk. III, 29). On the contrary, others are of themselves very light (Mt. XXIII, 24; Lk. VI, 42), so that they are often committed even by the just (James III, 2; I John I, 8).

3°) From which are understood both the malice of mortal sin which is in aversion from God (Jer. II, 13; Ezech. XVIII, 24), and its effect, because it deprives of the grace of God and of charity and of divine life, and inflicts on the soul death and eternal damnation.

Man namely who by grace is a) an adoptive son of God (John I, 12; Eph. I, 5; I John III, 1-2; Rom. VIII, 14-16); b) partaker of the divine nature, i.e. like God, holy and son of light (II Pet. I, 4; I John III, 2; Eph. IV, 25; V, 8); c) God's friend and temple (John XV, 14-15; I Cor. III, 16-17; VI, 19; John XIV, 23); d) worthy of eternal life and heir (Col. I, 12-13; Rom. VIII, 17; Tit. III, 7); e) capable of meriting it (John XV, 1-5; Mt. X, 42; Rom. VIII, 17; II Cor. IV, 17; II Tim. IV, 8; Heb. X, 35; VI, 10); — by mortal sin becomes a) son and servant of the devil (I John III, 8; John VIII, 44; II Pet. II, 19); b) partaker of his works, in which he walks in darkness and is unclean (I John I, 7-9; III, 8; Eph. V, 8; Col. I, 13; Heb. IX, 14); c) God's enemy (Rom. V, 10); d) worthy of hell (Mt. XXV, 41, 46; Mk. IX, 42; Apoc. XIV, 11, XX-XXII); e) incapable of meriting eternal life (John XV, 5-6).

B. Among the Fathers: 1°) In the first three centuries not explicitly but only confusedly was the distinction between mortal and venial sin maintained. They distinguished a) between greatest sins and lesser; b) between greatest and middle which were expiated by public penance, and smallest which were remitted by contrition, almsgiving, prayer, and other means of this kind. But in the 2nd and 3rd centuries three sins were considered as most grave: apostasy, adultery, and homicide, so that, in some Churches at least, pardon was not granted for them, at least before the article of death.

Which is evident from the testimony of Tertullian and S. Cyprian.

2°) From the 4th century the distinction between grave sins which are expiated by public penance, and light sins for which private penance suffices, is already had explicitly. Of which the witnesses are S. Ambrose and S. Augustine for the Latin Church; S. Gregory Thaumaturgus and S. Basil for the Greek Church.

3°) Afterwards around the 6th century especially rules by which are discerned the grave or capital sins and the light or minute are handed down, because the gravity of many had not been perceived up to that point. The enumeration can be found in Caesarius of Arles and in the Penitential books.

C. Among the Scholastics scientific analysis and deeper investigation is undertaken. They not only declare that those sins are distinguished by reason of effect and punishment, but by intrinsic nature, namely in the very notion of inordination by comparison namely to the last end, and to the eternal law, as was explained above.

533. Observations. — 1°a The aversion from God which constitutes actual mortal sin is not to be confused with the privation of grace. The latter is habitual aversion and effect of mortal sin; the former is inordination in the very evil act by which we act against charity and exclude it, namely actual deformity with charity and actual withdrawal from the end, which is the cause of the privation of grace: actual privation of habitual ordination. The former is the pure and total privation of charity, the other is not pure privation but a tendency to good with privation. Whence S. Thomas, de Malo q. 2, 9, ad 2: « The death of the soul is the privation of grace by which the soul is united to God; but the privation of grace is not essentially the fault itself but the effect of fault. Whence sin is called the death of the soul not essentially but effectively; essentially however it is a deformed or inordinate act ».

2°a He who sins mortally has himself as end to which, and as end which the created good itself, in which he inordinately delights and toward which he tends as to the last end; namely he loves his own good even to the contempt of God, or the convenience, comfort, excellence, abundance, wisdom of the sinner as disposed by himself, not as ordered by God, but connoting the privation of God.

3°a He who sins venially cannot refer that act to God: for that would be most injurious to God, — nor does he refer it to some created good as to the last end because then he would sin mortally; — but he simply refers it to happiness in common and abstractly willed. It is good in common under the notion of complete good, or one's own good according to the whole latitude, abstracting from the honest or delightful, good universally comprehending all the good of man.

4°a Since on the part of privation mortal and venial sin are of diverse order and differ in the whole genus and infinitely, it follows that all venial sins, even taken together, do not constitute one mortal, because they do not include properly so called aversion from God. Whence of himself he would not sin mortally who proposed to commit all venial [sins]; nor accidentally because of the danger of thus falling into mortal, because that proposal leads remotely only to mortal.

5°a Mortal [sin] being about the last end, venial however about those things which are to the end, is not to be so understood that the proximate object of the gravely sinful act is always the last end, the supreme good (or that mortal sin is always directly against God); but the proximate object of the lightly sinful act is always some means to the last end, a created good namely, whereas manifestly there are mortal sins which are proximately about means to the end, such as homicide, theft, etc., which holds when the means are necessary for the end. But understand that mortal sin is inordination about the end because it destroys the due order or conjunction with the last end; venial sin is inordination about the means alone which namely are not necessary for the end, because the will adheres too much to created goods, without however withdrawing from the last end. Therefore inordination about means necessary for the end is also about the end itself; but inordination about means not necessary is not inordination about the end.