Summa Theologica, by St. Thomas Aquinas, [1947], at sacred-texts.com
We must now consider cursing. Under this head there are four points of inquiry:
(1) Whether one may lawfully curse another?
(2) Whether one may lawfully curse an irrational creature?
(3) Whether cursing is a mortal sin?
(4) Of its comparison with other sins.
Objection 1: It would seem unlawful to curse anyone. For it is unlawful to disregard the command of the Apostle in whom Christ spoke, according to 2 Cor. 13:3. Now he commanded (Rom. 12:14), "Bless and curse not." Therefore it is not lawful to curse anyone.
Objection 2: Further, all are bound to bless God, according to Dan. 3:82, "O ye sons of men, bless the Lord." Now the same mouth cannot both bless God and curse man, as proved in the third chapter of James. Therefore no man may lawfully curse another man.
Objection 3: Further, he that curses another would seem to wish him some evil either of fault or of punishment, since a curse appears to be a kind of imprecation. But it is not lawful to wish ill to anyone, indeed we are bound to pray that all may be delivered from evil. Therefore it is unlawful for any man to curse.
Objection 4: Further, the devil exceeds all in malice on account of his obstinacy. But it is not lawful to curse the devil, as neither is it lawful to curse oneself; for it is written (Ecclus. 21:30): "While the ungodly curseth the devil, he curseth his own soul." Much less therefore is it lawful to curse a man.
Objection 5: Further, a gloss on Num. 23:8, "How shall I curse whom God hath not cursed?" says: "There cannot be a just cause for cursing a sinner if one be ignorant of his sentiments." Now one man cannot know another man's sentiments, nor whether he is cursed by God. Therefore no man may lawfully curse another.
On the contrary, It is written (Dt. 27:26): "Cursed be he that abideth not in the words of this law." Moreover Eliseus cursed the little boys who mocked him (4 Kings 2:24).
I answer that, To curse [maledicere] is the same as to speak ill [malum dicere]. Now "speaking" has a threefold relation to the thing spoken. First, by way of assertion, as when a thing is expressed in the indicative mood: in this way "maledicere" signifies simply to tell someone of another's evil, and this pertains to backbiting, wherefore tellers of evil [maledici] are sometimes called backbiters. Secondly, speaking is related to the thing spoken, by way of cause, and this belongs to God first and foremost, since He made all things by His word, according to Ps. 32:9, "He spoke and they were made"; while secondarily it belongs to man, who, by his word, commands others and thus moves them to do something: it is for this purpose that we employ verbs in the imperative mood. Thirdly, "speaking" is related to the thing spoken by expressing the sentiments of one who desires that which is expressed in words; and for this purpose we employ the verb in the optative mood.
Accordingly we may omit the first kind of evil speaking which is by way of simple assertion of evil, and consider the other two kinds. And here we must observe that to do something and to will it are consequent on one another in the matter of goodness and wickedness, as shown above (FS, Q[20], A[3]). Hence in these two ways of evil speaking, by way of command and by way of desire, there is the same aspect of lawfulness and unlawfulness, for if a man commands or desires another's evil, as evil, being intent on the evil itself, then evil speaking will be unlawful in both ways, and this is what is meant by cursing. On the other hand if a man commands or desires another's evil under the aspect of good, it is lawful; and it may be called cursing, not strictly speaking, but accidentally, because the chief intention of the speaker is directed not to evil but to good.
Now evil may be spoken, by commanding or desiring it, under the aspect of a twofold good. Sometimes under the aspect of just, and thus a judge lawfully curses a man whom he condemns to a just penalty: thus too the Church curses by pronouncing anathema. In the same way the prophets in the Scriptures sometimes call down evils on sinners, as though conforming their will to Divine justice, although such like imprecation may be taken by way of foretelling. Sometimes evil is spoken under the aspect of useful, as when one wishes a sinner to suffer sickness or hindrance of some kind, either that he may himself reform, or at least that he may cease from harming others.
Reply to Objection 1: The Apostle forbids cursing strictly so called with an evil intent: and the same answer applies to the Second Objection.
Reply to Objection 3: To wish another man evil under the aspect of good, is not opposed to the sentiment whereby one wishes him good simply, in fact rather is it in conformity therewith.
Reply to Objection 4: In the devil both nature and guilt must be considered. His nature indeed is good and is from God nor is it lawful to curse it. On the other hand his guilt is deserving of being cursed, according to Job 3:8, "Let them curse it who curse the day." Yet when a sinner curses the devil on account of his guilt, for the same reason he judges himself worthy of being cursed; and in this sense he is said to curse his own soul.
Reply to Objection 5: Although the sinner's sentiments cannot be perceived in themselves, they can be perceived through some manifest sin, which has to be punished. Likewise although it is not possible to know whom God curses in respect of final reprobation, it is possible to know who is accursed of God in respect of being guilty of present sin.
Objection 1: It would seem that it is unlawful to curse an irrational creature. Cursing would seem to be lawful chiefly in its relation to punishment. Now irrational creatures are not competent subjects either of guilt or of punishment. Therefore it is unlawful to curse them.
Objection 2: Further, in an irrational creature there is nothing but the nature which God made. But it is unlawful to curse this even in the devil, as stated above (A[1]). Therefore it is nowise lawful to curse an irrational creature.
Objection 3: Further, irrational creatures are either stable, as bodies, or transient, as the seasons. Now, according to Gregory (Moral. iv, 2), "it is useless to curse what does not exist, and wicked to curse what exists." Therefore it is nowise lawful to curse an irrational creature.
On the contrary, our Lord cursed the fig tree, as related in Mat. 21:19; and Job cursed his day, according to Job 3:1.
I answer that, Benediction and malediction, properly speaking, regard things to which good or evil may happen, viz. rational creatures: while good and evil are said to happen to irrational creatures in relation to the rational creature for whose sake they are. Now they are related to the rational creature in several ways. First by way of ministration, in so far as irrational creatures minister to the needs of man. In this sense the Lord said to man (Gn. 3:17): "Cursed is the earth in thy work," so that its barrenness would be a punishment to man. Thus also David cursed the mountains of Gelboe, according to Gregory's expounding (Moral. iv, 3). Again the irrational creature is related to the rational creature by way of signification: and thus our Lord cursed the fig tree in signification of Judea. Thirdly, the irrational creature is related to rational creatures as something containing them, namely by way of time or place: and thus Job cursed the day of his birth, on account of the original sin which he contracted in birth, and on account of the consequent penalties. In this sense also we may understand David to have cursed the mountains of Gelboe, as we read in 2 Kings 1:21, namely on account of the people slaughtered there.
But to curse irrational beings, considered as creatures of God, is a sin of blasphemy; while to curse them considered in themselves is idle and vain and consequently unlawful.
From this the Replies to the objections may easily be gathered.
Objection 1: It would seem that cursing is not a mortal sin. For Augustine in a homily On the Fire of Purgatory [*Serm. civ in the appendix of St. Augustine's works] reckons cursing among slight sins. But such sins are venial. Therefore cursing is not a mortal but a venial Sin.
Objection 2: Further, that which proceeds from a slight movement of the mind does not seem to be generically a mortal sin. But cursing sometimes arises from a slight movement. Therefore cursing is not a mortal sin.
Objection 3: Further, evil deeds are worse than evil words. But evil deeds are not always mortal sins. Much less therefore is cursing a mortal sin.
On the contrary, Nothing save mortal sin excludes one from the kingdom of God. But cursing excludes from the kingdom of God, according to 1 Cor. 6:10, "Nor cursers [Douay: 'railers'], nor extortioners shall possess the kingdom of God." Therefore cursing is a mortal sin.
I answer that, The evil words of which we are speaking now are those whereby evil is uttered against someone by way of command or desire. Now to wish evil to another man, or to conduce to that evil by commanding it, is, of its very nature, contrary to charity whereby we love our neighbor by desiring his good. Consequently it is a mortal sin, according to its genus, and so much the graver, as the person whom we curse has a greater claim on our love and respect. Hence it is written (Lev. 20:9): "He that curseth his father, or mother, dying let him die."
It may happen however that the word uttered in cursing is a venial sin either through the slightness of the evil invoked on another in cursing him, or on account of the sentiments of the person who utters the curse; because he may say such words through some slight movement, or in jest, or without deliberation, and sins of word should be weighed chiefly with regard to the speaker's intention, as stated above (Q[72], A[2]).
From this the Replies to the Objections may be easily gathered.
Objection 1: It would seem that cursing is a graver sin than backbiting. Cursing would seem to be a kind of blasphemy, as implied in the canonical epistle of Jude (verse 9) where it is said that "when Michael the archangel, disputing with the devil, contended about the body of Moses, he durst not bring against him the judgment of blasphemy [Douay: 'railing speech']," where blasphemy stands for cursing, according to a gloss. Now blasphemy is a graver sin than backbiting. Therefore cursing is a graver sin than backbiting.
Objection 2: Further, murder is more grievous than backbiting, as stated above (Q[73], A[3]). But cursing is on a par with the sin of murder; for Chrysostom says (Hom. xix, super Matth.): "When thou sayest: 'Curse him down with his house, away with everything,' you are no better than a murderer." Therefore cursing is graver than backbiting.
Objection 3: Further, to cause a thing is more than to signify it. But the curser causes evil by commanding it, whereas the backbiter merely signifies an evil already existing. Therefore the curser sins more grievously than the backbiter.
On the contrary, It is impossible to do well in backbiting, whereas cursing may be either a good or an evil deed, as appears from what has been said (A[1]). Therefore backbiting is graver than cursing.
I answer that, As stated in the FP, Q[48], A[5], evil is twofold, evil of fault, and evil of punishment; and of the two, evil of fault is the worse (FP, Q[48], A[6]). Hence to speak evil of fault is worse than to speak evil of punishment, provided the mode of speaking be the same. Accordingly it belongs to the reviler, the tale-bearer, the backbiter and the derider to speak evil of fault, whereas it belongs to the evil-speaker, as we understand it here, to speak evil of punishment, and not evil of fault except under the aspect of punishment. But the mode of speaking is not the same, for in the case of the four vices mentioned above, evil of fault is spoken by way of assertion, whereas in the case of cursing evil of punishment is spoken, either by causing it in the form of a command, or by wishing it. Now the utterance itself of a person's fault is a sin, in as much as it inflicts an injury on one's neighbor, and it is more grievous to inflict an injury, than to wish to inflict it, other things being equal.
Hence backbiting considered in its generic aspect is a graver sin than the cursing which expresses a mere desire; while the cursing which is expressed by way of command, since it has the aspect of a cause, will be more or less grievous than backbiting, according as it inflicts an injury more or less grave than the blackening of a man's good name. Moreover this must be taken as applying to these vices considered in their essential aspects: for other accidental points might be taken into consideration, which would aggravate or extenuate the aforesaid vices.
Reply to Objection 1: To curse a creature, as such, reflects on God, and thus accidentally it has the character of blasphemy; not so if one curse a creature on account of its fault: and the same applies to backbiting.
Reply to Objection 2: As stated above (A[3]), cursing, in one way, includes the desire for evil, where if the curser desire the evil of another's violent death, he does not differ, in desire, from a murderer, but he differs from him in so far as the external act adds something to the act of the will.
Reply to Objection 3: This argument considers cursing by way of command.