Summa summae S. Thomae, Tomus II

Note. Venial sins are of a threefold kind. 1° Some are venial from genus or from object, as an idle word, immodest laughter. 2° Some are venial from lightness of matter, as slight theft. 3° Some are venial from imperfection of the act which is not fully deliberate, as motions second of first, concerning an object mortally evil.

I say 1°: Venial sin from genus disposes indirectly to mortal from genus, not directly; but to mortal on the part of the agent it disposes directly ¹.

The first part is proved. 1° From that Eccli., XIX, 1 : He that despiseth small things shall fall by little and little ². 2° Indirect disposition is by way of one removing and preventing. But venial sin from genus diminishes the subjection of the will under God and the fervor of charity, and at the same time places an obstacle to divine helps, whereby man is contained and preserved from mortal sin. Therefore.

The second part is proved. Direct disposition is toward the form of the same species, or is per se subordinated to it. But venial sin from genus is of different species from mortal sin from genus, nor is it per se subordinated to it, as is evident, e.g., in an idle word with respect to homicide. Therefore.

The third part is proved ³. From venial sins frequently committed in some genus, e.g., from habit of playing, the love of play can grow so much that finally on account of it one sins mortally, e.g., Mass be omitted on a feast day. Therefore.

I say 2°: Venial sin from imperfection of act, or from lightness of matter, disposes directly to mortal. Thus, e.g., small theft disposes directly to great theft; semi-plenary consent to homicide disposes directly to it; because, although they are of different formal species, they are nevertheless of the same material species, since they turn about the same material object.

I say 3°: An act remaining the same in number in natural being can become from venial mortal. Thus consent imperfectly deliberated concerning a mortal object is venial sin; if it continue physically with full deliberation, it becomes mortal ⁴. But an act remaining the same in number in moral being cannot become from venial mortal; because sin principally consists in the act of the will, as every moral act: whence an act is not called one in number morally, if the will is morally changed, even though the action in natural being be continuous. But, while the act which was before venial becomes mortal, the will is morally changed; for if it were not changed, it would not become from venial mortal. Therefore.

It is confirmed. What is of a lower order, however much it be increased within its order, cannot attain to what is of a higher order: thus, however much silver be perfected in its order, it cannot attain the grade of gold. But venial act is of a lower order in moral being than mortal sin; for this is aversive from the last end, not that. Therefore the same in number remaining in moral being cannot become mortal.

I say 4°: Sin which would be venial from its genus can become mortal in several ways on the part of the agent and circumstances:

1° By reason of mortal end: as if anyone should tell an officious lie with the intention of fornicating. Yet since that lie draws its mortal malice from the deadly intention, it suffices to accuse that intention, or the fornication, if it followed, saying: « I had the intention of fornicating, » or: « I have fornicated ».

2° By reason of erroneous conscience: as if you think that to which you set your hand is mortal when it is venial.

3° By reason of grave detriment, whether spiritual (which is scandal) or temporal, which is foreseen or can easily be foreseen as about to follow.

4° By reason of proximate danger of sinning morally.

5° If the last end be constituted in venial sin; which happens when the sinner, by a sin venial of itself, is actually disposed in mind to transgress a precept binding under mortal sin rather than abstain from his venial sin.

6° By reason of formal contempt. Formal contempt is twofold: one perfect, when anyone refuses in all things to submit to a superior. Any sin whatever, even in a light matter, from such contempt is mortal; for to contemn the whole superiority is a grave thing: The other is imperfect, when anyone refuses to submit to a superior in some matter only, whether grave or light, being ready to obey him in other things; and such contempt in a grave matter is mortal, in a light matter venial; unless perhaps the contempt were of God himself or his precept, because then it would be blasphemous. So distinguish Cajetan and Sylvius.

You will ask whether he would sin mortally who had the resolve of committing all venial sins.

I answer. Sanchez and others affirm it, with this reason, that, as St. Thomas teaches, venial sins of themselves dispose to mortal. More probably however it is denied with the Salmanticenses and St. Alphonsus, contempt or proximate danger of falling into mortal being set aside, regard being had to past experience. The reason is because such a resolve leads only remotely to mortal.

I say 5°: However much venial sins be multiplied, they can never effect one mortal sin, nor be equivalent to it ⁵. It is common doctrine against the gloss in cap. Tres sunt, de Poenit., dist. 1, which was deleted by pontifical authority as erroneous.

The reason is, because however much venial sins be multiplied, they cannot turn away from the last end; for neither does the first turn away, nor yet the second, which is of the same account, and so of the rest. Nor can they inflict guilt of eternal punishment, which infinitely differs from temporal punishment, which venial sin merits.

It is confirmed. The Church teaches that all mortal sins must necessarily be confessed, not venial ones, even multiplied: otherwise, since it is not known how far they must be multiplied so as to effect one mortal sin, as soon as anyone had committed more, he would be bound to confess in doubt; which is false and against the practice of the Church.

I say 6°: Sin which of itself would be mortal can become venial from two heads ⁶ : 1° from imperfection of act, which may not be fully deliberate; 2° from lightness of matter.

The reason of the first part is, because for mortal sin, whereby man is turned away from God and incurs guilt of eternal punishment, there is required no less an act perfectly voluntary and free than is the meritorious act of eternal life. Such however it is not without perfect deliberation on the part of the intellect, and without full consent on the part of the will.

The reason of the second part is, because laws regularly bind according to the condition of matter, gravely where matter is grave, lightly where it is light. Consequently transgression in a light matter is a light offense.

To be specially observed for practice.

You will ask 1° what is perfect, what imperfect deliberation.

I answer. Perfect deliberation is when the intellect without disturbance or impediment fully and distinctly apprehends and adverts, or can and ought to advert, to the act and its malice. To this perfect deliberation on the part of the intellect follows, on the part of the will, full consent, if it be given. I say: If it be given; because while the intellect perfectly deliberates and adverts to the evil act, not rarely the will denies consent: which regularly happens in fearful men.

Imperfect deliberation is when someone half asleep or half drunk, or almost half asleep, distracted by various thoughts, or assailed by vehement passion, apprehends or can apprehend the evil act not fully and distinctly, but only confusedly, and the obligation of avoiding it. And then the consent of the will following is necessarily imperfect and semiplenary.

The signs of imperfect consent are: 1° If, as already said, it follows from imperfect deliberation. 2° If anyone, fully adverting to the temptation, immediately repels it, or is so disposed in mind that, if he could easily execute the sin, he would not will to, or would rather choose death than offend God lethally, it is more probable that he did not fully consent; because full and firm affection is not easily changed, and when it is changed, it is easily adverted to. 3° He who is of fearful conscience, and is wont to resist temptation while he fully adverts to it, can prudently judge in doubt that he did not fully consent. Otherwise, if he be of freer conscience, and is wont to consent, because judgment is prudent from commonly occurring circumstances. 4° He who doubts whether in sleep or waking he suffered disordinate motions, can judge that he did not consent fully and deliberately; because, if deliberation had been full, he would know himself to have been perfectly aroused from sleep. 5° Long duration of temptation is not sufficient argument of perfect, nay not even of imperfect consent; for temptation can long endure, the will resisting.

You will ask 2° in what sins lightness of matter excusing from mortal is given or not given.

I answer. Lightness of matter excusing from mortal is not given in sins in which, notwithstanding the apparent lightness of matter, there is found entire irreverence of the divine Majesty and grave violation of the charity of God and neighbor; because gravity of sin is drawn from the gravity of irreverence of divine Majesty, or of violation of charity. Therefore, where grave irreverence or violation of charity is found in small as in great quantity of matter, the gravity of sin remains.

But in those sins in which from diminution of matter the gravity of irreverence toward God or of violation of charity is diminished, lightness of matter excusing from mortal is given; because matter can be so diminished and decreased that it suffice only for light irreverence or light violation of charity.

Hence you will infer 1° that parvity of matter excusing from mortal is not given in sins which are committed directly against God, as are all sins against the theological virtues; because, although in a most light matter you deny faith to God, or despair of him, or hold him in hatred or contempt, or formally blaspheme him, you gravely offend his truth, power, goodness, majesty.

You will infer 2° In sins which are against Religion, sometimes parvity of matter excusing from mortal is given, sometimes not. It is not given in superstition of worshipping false deity, as idolatry, divination and vain observance. I say the same of magic and maleficium; because to worship false deity in even the smallest thing, or to hold society, whether explicitly or implicitly, with the devil, is the gravest injury offered to true deity.

There can however be given in divination and vain observance lightness, not of matter, but of act, excusing from mortal: as if anyone attempt divination without express invocation of the demon, out of jest or levity, not believing it useful, but altogether vain and useless, or knowing not that there is any invocation of the demon therein, he does not sin mortally. Let the same judgment be, if from a dream, augury and similar things he conceive some fear of things future, but nevertheless do not believe it; or if once and again he do or omit something free to him from such fear, yet do not direct his life and actions according to the norm of such divinations. I say the same of vain observance of healths or events: as if anyone out of simplicity or non-culpable ignorance, or out of excessive timidity, leave the table because thirteen sit there, fearing thence someone's death; or if because in going out of the house in the morning he strike his foot, or a hare run across him, he fears an unlucky journey, and therefore returns home; or if he promise himself certainly and infallibly a good death, if he honor such a saint, recite daily such a prayer.

But in superstition of undue worship, especially superfluous, of true deity, lightness of matter excusing from mortal seems able to be given: as if anyone pray before sunset, or with a certain number, position, color of candles, or will to hear Mass from a priest called John, or repeat Alleluia, or make more crosses than is ordained by the Church, or abstain from certain servile work, put sewing, on Saturdays, in honor of the Blessed Virgin, while he indulges in other servile works. For in these and similar things, contempt and scandal set aside, no grave injury seems to be done.

In simony parvity of matter excusing from mortal is not given; because, however little the thing be in degree of spirituality, it is always a great injury to value it at an earthly price; and the less price is paid for a spiritual thing, the less it seems to be valued. Nor is it given in assertory oath; because it is always grave irreverence and injury to will God to be witness of a falsehood, as if he could be deceived or deceive, even in the smallest matter. Otherwise, according to the opinion more probable to us, of promissory oath, in which God is invoked not as witness of truth or falsehood, but is taken as quasi-sponsor of the obligation of the swearer, which obligation does not consist in an indivisible, but is greater or lesser, according to the account of matter of greater or lesser moment, of which I spoke at length in tract. de Religione, dissert. V, a. 6, § 1.

Likewise lightness of matter is given in vow, whether it be total matter or part of the total matter of the vow, concerning which see also ibid., dissert. IV, a. 3, concl. 3. In sacrilege which is done from direct intention of dishonoring sacred things, lightness of matter is not given, on account of formal contempt of the sacred thing, which is reduced to God. But done for another end, it admits lightness of matter excusing from mortal: thus slight theft in a sacred place is venial sin.

You will infer 3° that lightness of matter excusing from mortal is given in sins which are against the precepts of the second table, or which are against neighbor and self and against ecclesiastical precepts, as in theft, beating, wounding, detraction, insult, cursing, anger, vengeance, avarice, ambition, gluttony, ecclesiastical fast, etc.; because in these the less the matter, the less the injury done to self or neighbor.

You will ask 3° whence is to be estimated the gravity or levity of matter in those sins which admit it.

I answer. That it is to be estimated from this, that, according to the judgment of prudent men and doctors, it conduces gravely or lightly to the grave end of the law; so that matter is grave which conduces gravely to the end of the law; light, which lightly, whether it be a third part, or a fourth, or a twentieth, or a hundredth part of the whole. I said, according to the judgment of prudent men and doctors, because upon it chiefly depends discerning what matter conduces gravely or lightly to the end of the law.

It must be noted however, concerning the time at which the law begins or ceases to bind, e.g., of fast, that lightness of matter is not given: so that, if immediately after hearing the twelfth hour of the night of Friday, or immediately before the twelfth of Sunday, you eat meat, the matter is grave and the sin mortal; because that negative precept binds the whole day of the fast, always and forever, excluding every part of that day from eating meat. The same seems to be said of the time required by law for receiving sacred Orders, making profession, contracting marriage, etc. Nor stands in the way what is commonly said: « That what differs little seems to differ nothing; » for this axiom does not hold in things fixed by law, which consist in an indivisible, and thus the common sense apprehends.