Article I: On the Difference Between Mortal and Venial Sin

St. Thomas, 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 sins. - This is of faith from universal preaching, confirmed in the Second Council of Lyons, profession of faith of Michael 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 several ways:

1. as to the debt of punishment: for mortal sin merits eternal punishment, but venial sin temporal punishment. Yet, says St. Thomas (De Malo q. 7, a. 1), "that difference follows upon the account of mortal and venial sin, but does not constitute it. For sin is not such because such a punishment is owed to it, but rather conversely, because the sin is such, therefore such a punishment is owed to it";

2. as to effect, for mortal sin deprives of grace, which is the supernatural life of the soul, and therefore of itself is irreparable and is called mortal (together with grace the connected gifts are 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 sin does not take away (nor diminish) grace, which is the principle of pardon and condonation, and therefore of itself is reparable and is called venial.¹ But neither is this the constitutive difference: for from the fact that some sin is grave, it has privation of grace as its effect and is irreparable, and not conversely. Hence:

¹ "Sin is as it were a sickness of the soul. Therefore just as there are certain curable diseases, and certain incurable ones which are called mortal, so there are certain curable sins which are called venial, and certain sins (as far as they are of themselves) incurable, although they can be cured by God, which are called mortal." De Malo, q. 7, a. 1.

3. in the very account of disorder the fundamental and intrinsically constitutive difference is to be sought. For disorder is twofold: "One by subtraction of the principle of order; another by which, the principle of order being preserved, inordination occurs concerning those things which are after the principle ... But the principle of the whole order in morals is the ultimate end ... Hence when the soul is disordered by sin concerning the ultimate end itself, even to aversion from God, to whom it is united by charity, it is mortal sin"; but when without aversion from the end disorder occurs only concerning those things which are toward the end, then it is venial sin (q. 72, a. 5). In other words: in mortal sin man constitutes for himself an ultimate end contrary to God, and therefore recedes from God and turns himself away (against the order of the end); in venial sin he inordinately adheres to those things which are toward 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 first two follow.

531. Mortal and venial sin differ on the part of the formal element or privation. - For in each there is undue conversion to created good which cannot be referred to the ultimate end, and according to this they can pertain to the same species (for example, theft). But in mortal sin man is so converted to created good as if it were totally his ultimate end, whence to the conversion is joined the privation of every order to God as to the end, and this privation is aversion or recession from God; on the contrary, in venial sin man is converted to a creature, not as to the ultimate end, but places 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 habitual order to him remains; and this privation is only retardation or distancing from the end. Hence on the part of privation mortal and venial sin differ from the whole genus and infinitely, for, as St. Thomas says (q. 87, a. 5, ad 1), "the ultimate end differs infinitely from those things which are toward the end."

In other words, in each there is an act tending to something prohibited by law, but the difformity with law is very diverse. For the law primarily commands the very essence of moral order, or the order itself of subjection to God the ultimate end; secondarily (as the complement of order) it commands the mode by which this is done, namely, that nothing be done except toward this end. Hence something can be against law in two ways: 1. simply and perfectly, because it turns one away from God, the highest good, and destroys the essence of moral order, the very subjection to the Ultimate End, and in this way mortal sin is against law; 2. imperfectly and in a certain respect, because although it does not contain aversion from the ultimate end, nevertheless it is not referable to the ultimate end, God, to whom we are bound to refer ourselves and all our things: in this second way venial sin is against law; but because it is not against the law of subjection to God but only against the mode which the law intends, it is better called beside the law. Therefore in mortal sin there is difformity with the essential and primary ordination of the law commanding what is altogether necessary to the end, and therefore it is called against the law, that is, against the end of the law, which is charity by which we are subjected and united to God; in venial sin there is only difformity with the accidental and secondary ordination of the law, which commands something useful to the end, and therefore it is called beside the law, that is, beside the end of the law, but against only the means to the end, without overturning subjection to the end. And therefore the notion of sin is analogical (ad 1).

532. From this is understood the revealed and theological doctrine concerning the nature of mortal sin:

A. In the Scriptures: 1. Christ himself teaches that there are absolutely grave sins, which are the cause of grave punishment, indeed of eternal damnation: "Whoever shall say to his brother: fool, shall be liable to the hell of fire" (Matt. V, 22); "Depart from me, accursed, into everlasting fire" (Matt. XXV, 41-42). Hence the Apostles also 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. Yet there are sins relatively graver than others: "He who handed me over to you has the greater sin" (John XIX, 11; cf. Jer. VII, 26); indeed certain ones are so grave that from their nature and as it were without a miracle of God they are called "irremissible" (Matt. XII, 31; Mark III, 29). Conversely, others of themselves are very light (Matt. XXIII, 24; Luke VI, 42), so that they are often committed even by the just (James III, 2; I John I, 8).

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

Namely, man, who through grace is a) an adoptive son of God (John I, 12; Eph. I, 5; I John III, 1-2; Rom. VIII, 14-16); b) a participant of the divine nature, that is, like to God, holy and a son of light (II Pet. I, 4; I John III, 2; Eph. IV, 25; V, 8); c) a friend and temple of God (John XV, 14-15; I Cor. III, 16-17; VI, 19; John XIV, 23); d) worthy of eternal life and an heir (Col. I, 12-13; Rom. VIII, 17; Tit. III, 7); e) capable of meriting it (John XV, 1-5; Matt. X, 42; Rom. VIII, 17; II Cor. IV, 17; II Tim. IV, 8; Heb. X, 35; VI, 10); - through mortal sin becomes a) a son and servant of the devil (I John III, 8; John VIII, 44; II Pet. II, 19); b) a participant of his works, by 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) an enemy of God (Rom. V, 10); d) worthy of hell (Matt. XXV, 41, 46; Mark IX, 42; Apoc. XIV, 11, XX-XXII); e) incapable of meriting eternal life (John XV, 5-6).

B. Among the Fathers:² 1. In the first three centuries the distinction between mortal and venial sin was not explicitly but only confusedly established. They distinguished a) between the greatest sins and lesser sins; b) between the greatest and middle sins, which had to be expiated by public penance, and minute sins, which were remitted by contrition, almsgiving, prayer, and other means of this kind. But in the second and third century three sins were held as most grave: apostasy, adultery, and homicide, so that in at least certain Churches pardon was not conceded to them, at least before the article of death.

² Cf. Tanquerey, Th. Mor. fund., n. 453-459.

These things are clear from the testimony of Tertullian and St. Cyprian.

2. From the fourth century the distinction is already had explicitly between grave sins, which are to be expiated by public penance, and light sins, for which it suffices to do penance privately. Witnesses of this are St. Ambrose and St. Augustine for the Latin Church; St. Gregory Thaumaturgus and St. Basil for the Greek Church.

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

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

533. Remarks. - 1. Aversion from God, which constitutes actual mortal sin, is not to be confused with privation of grace. This is habitual aversion and the effect of mortal sin; that is the inordination in the evil act itself by which we act against charity and exclude it, namely, actual difformity with charity and actual recession from the end, which is the cause of the privation of grace: the actual privation of habitual ordering. The former is the pure and total privation of charity; the latter is not pure privation but a tendency to good with privation. Hence St. Thomas, De Malo q. 2, a. 9, ad 2: "The death of the soul is the privation of grace through which the soul is united to God; but the privation of grace is not essentially guilt itself but the effect of guilt. Hence sin is called the death of the soul not essentially but effectively; but essentially it is a deformed or inordinate act."

2. He who sins mortally has as the end to which he orders himself, himself; as the end which he seeks, the created good itself, concerning which he unduly rejoices and toward which he tends as toward the ultimate end; namely, his own good loved even to contempt of God, or the suitability, convenience, excellence, abundance, wisdom of the sinner as disposed by himself, not as ordered by God, but connoting the privation of God.

3. He who sins venially cannot refer that act to God: for this would be most injurious to God, - nor does he refer it to some created good as to the ultimate end, because then he would sin mortally; - but simply refers it to happiness in common and abstractly willed. It is good in common under the aspect of complete good, or one's own good according to its whole breadth, abstracting from honorable or delectable good, a good universally comprehending every good of man.

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

5. That mortal sin is concerned with the ultimate end, but venial sin with those things which are toward the end, is not to be understood as though the proximate object of a gravely sinful act were always the ultimate end, the highest good (or that mortal sin is always directly against God); but the proximate object of a lightly sinful act were always some means to the ultimate end, namely, a created good, since there manifestly are mortal sins which are proximately concerned with means to the end, such as homicide, theft, etc., which has place when the means are necessary to the end. But understand that mortal sin is an inordination concerning the end because it destroys due order or conjunction with the ultimate end; venial sin is an inordination concerning only means which, namely, are not necessary to the end, because the will adheres too much to created goods, without nevertheless receding from the ultimate end. In other words: inordination concerning means necessary to the end is also concerning the end itself; but inordination concerning means not necessary is not inordination concerning the end.