Summa Theologiae Moralis, vol. I: De Principiis

S. Th. I-II q. 88, a. 2 and 6; De Malo q. 7, a. 1 and 3.

538. Conditions required for mortal sin. — In perfect or mortal sin there are two elements: a) objective, namely grave malice, b) subjective or the act perfectly deliberate and voluntary. Hence three conditions are required for it:

1°a) gravity of malice in the object, otherwise it would not be gravely evil; it also suffices that there be gravity in the object, i.e. in the thing or action as apprehended, and grave malice in the thing or action as it is in itself is not necessarily required: for it suffices that man in fact will grave evil. Therefore there must be present grave transgression of law in itself or at least from false estimation;

2°a) grave advertence to the malice, for if the gravity is not adverted to, man cannot will it, and the offense will be light; and indeed full advertence or perfect deliberation, otherwise the malice would not be perfectly willed and the condition would fail;

3°a) perfect consent of the will: for no one is considered to convert himself to something as to the last end and to love it above all things and to separate himself entirely from God, except through a perfectly human and voluntary act. Then in as much as something is sin, it is voluntary; therefore if it is imperfectly voluntary, sin is imperfect. Finally it is repugnant to divine goodness to punish man with eternal punishments without full consideration and consent on his part.

539. The malice of the object, whose gravity we must advert to, is understood either as grave in itself, i.e. from the object, or from circumstances, as from the end, scandal, peril adjoined, etc. as will be said in art. 5. That the gravity (or lightness) of malice may be easily discerned, the following rules are wont to be handed down by theologians:

1°a is taken from Scripture: when some sin is afflicted with grave appellations, it is to be judged mortal, e.g. if it calls it crime, wickedness, iniquity, abomination, or says it to be worthy of death, hateful to God, to bring death, to exclude from the kingdom of heaven, to cry to heaven, or if a curse is applied to it, e.g. woe (Lev. XXIV, 14, 16, 17, 23; Prov. VI, 16; Is. V, 20; Rom. I, 18 sq., I Cor. VI, 8-VII; Gal. V, 19; Eph. V, 3); — on the contrary sin is reputed only venial, when Scripture uses milder words, as with the name of mote, straw, hay, etc. (I Cor. III, 12; Mt. XXIII, 24; Lk. VI, 41), or rebukes it with a lighter correction (Prov. X, 19; Mt. XII, 36).

2°a is taken from Tradition: mortal are those which are held as such in Pontifical and Conciliar decisions, or from the morally unanimous consensus of the Holy Fathers or Doctors, or even from the practice of God-fearing men. However about the ancient Fathers one must carefully attend what was their manner of speaking (e.g. whether perhaps exaggerated in the manner of an orator), and what was the discipline of those times (e.g. whether perhaps grave punishment for lesser fault or vice versa).

3°a is taken from reason: sins are mortal which take away the order to the last end, or dissolve the charity of God or of self or of neighbor; such are those by which the subjection and reverence of man to God is taken away (e.g. blasphemy, superstition of a false deity); — or by which grave harm is incurred to one's own corporal or spiritual salvation, which is a necessary condition for the last end, the love and glory of God; — or by which those things are taken away without which human society cannot be preserved, which is a means necessary for man to attain the last end, such as rebellion, homicide, adultery, theft, disobedience in a matter of great moment: for men could not live together if these were perpetrated everywhere and indifferently, as we said distinguishing the primary and secondary precepts of natural law (n. 251, C).

Or also: mortal sins are those which are directly opposed to the primary precepts of natural law, or which violate the moral order primarily intended by nature. For the observance of the primary order is a necessary condition for attaining the last end. Therefore a substantial violation of the primary order is mortal sin. Hence mortal are: a) those which violate the very order to God or take away subjection to Him (blasphemy, perjury), but not those which are only against the manner of subjection; — b) those which violate the order of man to himself, and are a direct disposition of himself or of his faculties against the very ordination of rational nature, or without due subordination to the human species and the common good (suicide, drunkenness, pollution), but not those which are only against the manner of disposing; — c) those which violate the order toward neighbor, while notably inflicting harm or offense on one who is gravely unwilling (homicide, adultery, theft), but not those which only do not observe the due manner or by which neighbor is not much unwilling (n. 251, A, b).

Disobedience however in a grave matter is had also in positive law; whence those are mortal which are done against a law prescribing under grave matter: for then by that very fact man acts against those things without which human society cannot be preserved, for the violation of a precept which is of great moment for the common good is born to notably harm society. But law obliges under grave matter when the matter is grave, i.e. much conducive to an end of great moment, and at the same time the legislator wishes to prescribe under grave matter; about which is to be judged according to the rules handed down in the tr. on Laws, n° 343.

In practice let not that be called mortal whose grave malice does not certainly appear.

540. Advertence of the intellect is present 1°) to grave malice, if man understands something to be so evil or prohibited by God that together with his love, or friendship, or grace, or conjunction to him as end it cannot consist, or at least understands this implicitly, e.g. knowing something to be very base, strictly prohibited, notably disturbing the moral order, very opposed to the divine will, inducing the enmity of God, worthy of grave punishment, etc., or whatever else distinctive of grave sin he perceives in some way¹.

Hence S. Thomas, q. 88, a. 2, ad 1: « from this very fact that someone chose that which is repugnant to divine charity, he is convicted of preferring it to divine charity; and consequently of loving it more than God. And therefore some sins generically which of themselves are repugnant to charity, have that something is loved above God; and thus are by their genus mortal ».

There is required however 2°) full advertence or perfect deliberation, which however is not the greatest possible, but that by which man, fully master of himself, is wont to attend to a matter of sufficiently great moment. And indeed:

a) Subjectively obscure and imperfect does not suffice, but full and perfect is required, by which man, wakeful, with mind free, nor impeded by any notable distraction or carried away by disturbance, adverts to the gravity of the malice whether immediately, at the moment when the evil act is placed, or mediately, when the cause is placed from which the evil effect is foreseen to follow, at least in confused manner.

b) Objectively indeed distinct is not required but confused suffices: for it is not required that grave malice be apprehended distinctly, but it suffices that it appear in confused manner, by doubting about it or suspecting it, or by adverting that there is danger of it, or that there is obligation to attend to it or to attend more, and this whether at the moment when the evil is done or at the moment when the cause is placed from which it is foreseen to follow: then indeed if one nonetheless chooses it, he already fully wills it even if it is grave evil (n. 214), and therefore in fact wills grave evil, and so despises the love of God and the last end and loves it more, and implicitly and virtually chooses also aversion from God and leaves the last end (a. 2, ad 1). Hence confused advertence is not for that reason obscure, but can be full and perfect².

c) Reflex is not required, by which man knows that he adverts, but direct advertence to the malice itself suffices, such as is also drawn from habitual knowledge and can scarcely be absent in those things which are habitually known and frequently recalled to memory: thus if a sacred person sins against chastity, although he does not explicitly think of sacrilege, he nevertheless adverts to it implicitly or in act exercised, since he knows that he is and not another who perpetrates such things; likewise he who willingly lingers in base thoughts which usually induce pollutions or who is accustomed to deal familiarly with women. Likewise for full advertence duration of time is not required, nor is this a sign of it.

Conjectural signs of imperfect advertence are handed down by theologians as follows: a) if occupied with another thing and distracted you have grasped the thing to be evil only slightly and superficially; b) if half-asleep or half-delirious you were not yet perfectly master of yourself; c) if unmindful after the deed you scarcely remember what you did; d) if, when you consider better, you judge, according to your habitual disposition, that you would not have done the deeds if you had so apprehended them; e) if you were so carried away by distraction or passion that you were occupied with the knowledge only of utility, harm, advantage or disadvantage to be perceived from the work, not of its malice; f) or if you labored or were disturbed by most vehement passion (of anger, fear, sadness), apprehension, agitation of nerves or mania, or pathological state, so that you almost did not know what you were doing (which often happens in evil thoughts, detractions, sins from which damages or dangers for others follow).

Imperfect advertence is ordinarily present and therefore is presumed in the half-asleep, those just waking up, suddenly terrified, half-mentally-ill, half-drunk, young children (before the seventh year), childish old people, the very scrupulous; — on the contrary full advertence, at least confused but sufficient, is supposed in the customary and hardened sinners.

541. The consent of the will is full, when from full deliberation or advertence of mind, he chooses the act whether directly and immediately when the transgression is here and now placed, or mediately or indirectly when a positive cause or omission is placed from which the transgression is foreseen to follow, at least in confused manner. — On the contrary the consent is semi-full if the will follows a semi-full advertence of intellect, or if it indolently with some torpor repels the suggestion of evil less than it ought, as if the passion of the sensitive appetite is moved but the will tepidly resists.

Conjectural signs of imperfect consent are handed down by theologians as follows: a) if one, fully adverting to the temptation, immediately repels it; b) if adverting more fully, he is immediately grieved or saddened; c) if, as soon as he is grieved, he still finds himself so habitually constituted that he would rather die than sin mortally; d) if he could easily have executed the sin and did not execute it; e) if a God-fearing man (or one who is wont to be so affected that he would rather die than expressly sin mortally) doubts whether he consented; f) if one proceeded very timidly and in suspense, he remembers; g) if he was half-asleep, not fully master of himself, he judges that he would not have done the deed, if he had been fully awake; h) if he doubts whether he was master of himself, awake, not drunk.

In doubt: imperfect consent is presumed in God-fearing men and in those who are wont to be so disposed that they would rather die than sin mortally, because if they had perfectly consented, ordinarily they would not doubt; — on the contrary it is presumed perfect in those who are of laxer conscience and easily fall into some sin: these, if they had resisted the temptation better than usual, would certainly know it.

542. Corollaries. — 1. He who knows that he is acting badly, but does not know whether the evil is grave or light: a) if he adverts to the danger of grave sin at least in confused manner and doubts about this, he sins gravely because he deliberately exposes himself to the danger of gravely offending God: for he knows that his action perhaps gravely offends God and nevertheless does not abstain from it (cf. tr. on Consc^a, n. 214);

b) if however he thinks nothing at all about gravity or lightness, he does not sin gravely, because he apprehends grave malice in no way.

2. He who deliberates about committing grave sin, whether namely he ought to consent to sin, but so that he does not consent: a) if the deliberation is true and full, so that, the gravity of the malice being proposed, he inquires whether he would will the gravely evil thing or not, he sins gravely, because he compares God with a creature, doubtful whether he prefers God or the creature, esteeming that it can happen that the created good is placed before the divine friendship; which is injurious to God;

b) if the deliberation is imperfect, or only some hesitation or omission of resistance against the temptation from negligence or torpor, it does not exceed venial sin³.