Thomas Aquinas, Summa Theologiae

Objection 1: It seems that boasting is a mortal sin. For it is written (Prov. 28:25): "He that boasteth, and puffeth himself, stirreth up quarrels." Now it is a mortal sin to stir up quarrels, since God hates those that sow discord, according to Prov. 6:19. Therefore boasting is a mortal sin.

Objection 2: Further, whatever is forbidden in God's law is a mortal sin. Now a gloss on Ecclus. 6:2, "Extol not thyself in the thoughts of thy soul," says: "This is a prohibition of boasting and pride." Therefore boasting is a mortal sin.

Objection 3: Further, boasting is a kind of lie. But it is neither an officious nor a jocose lie. This is evident from the end of lying; for according to the Philosopher (Ethic. iv, 7), "the boaster pretends to something greater than he is, sometimes for no further purpose, sometimes for the sake of glory or honor, sometimes for the sake of money." Thus it is evident that it is neither an officious nor a jocose lie, and consequently it must be a mischievous lie. Therefore seemingly it is always a mortal sin.

On the contrary, Boasting arises from vainglory, according to Gregory (Moral. xxxi, 17). Now vainglory is not always a mortal sin, but is sometimes a venial sin which only the very perfect avoid. For Gregory says (Moral. viii, 30) that "it belongs to the very perfect, by outward deeds so to seek the glory of their author, that they are not inwardly uplifted by the praise awarded them." Therefore boasting is not always a mortal sin.

I answer that, As stated above (Question 110, Article 4), a mortal sin is one that is contrary to charity. Accordingly boasting may be considered in two ways. First, in itself, as a lie, and thus it is sometimes a mortal, and sometimes a venial sin. It will be a mortal sin when a man boasts of that which is contrary to God's glory---thus it is said in the person of the king of Tyre (Ezech. 28:2): "Thy heart is lifted up, and thou hast said: I am God"---or contrary to the love of our neighbor, as when a man while boasting of himself breaks out into invectives against others, as told of the Pharisee who said (Lk. 18:11): "I am not as the rest of men, extortioners, unjust, adulterers, as also is this publican." Sometimes it is a venial sin, when, to wit, a man boasts of things that are against neither God nor his neighbor. Secondly, it may be considered with regard to its cause, namely, pride, or the desire of gain or of vainglory: and then if it proceeds from pride or from such vainglory as is a mortal sin, then the boasting will also be a mortal sin: otherwise it will be a venial sin. Sometimes, however, a man breaks out into boasting through desire of gain, and for this very reason he would seem to be aiming at the deception and injury of his neighbor: wherefore boasting of this kind is more likely to be a mortal sin. Hence the Philosopher says (Ethic. iv, 7) that "a man who boasts for the sake of gain, is viler than one who boasts for the sake of glory or honor." Yet it is not always a mortal sin because the gain may be such as not to injure another man.

Reply to Objection 1: To boast in order to stir quarrels is a mortal sin. But it happens sometimes that boasts are the cause of quarrels, not intentionally but accidentally: and consequently boasting will not be a mortal sin on that account.

Reply to Objection 2: This gloss speaks of boasting as arising from pride that is a mortal sin.

Reply to Objection 3: Boasting does not always involve a mischievous lie, but only where it is contrary to the love of God or our neighbor, either in itself or in its cause. That a man boast, through mere pleasure in boasting, is an inane thing to do, as the Philosopher remarks (Ethic. iv, 7): wherefore it amounts to a jocose lie. Unless perchance he were to prefer this to the love of God, so as to contemn God's commandments for the sake of boasting: for then it would be against the charity of God, in Whom alone ought our mind to rest as in its last end.

To boast for the sake of glory or gain seen to involve an officious lie: provided it be do without injury to others, for then it would once become a mischievous lie.

Articulus 2

Argumentum 1

Ad secundum sic proceditur. Videtur quod iactantia sit peccatum mortale.

Dicitur enim Prov. XXVIII, qui se iactat et dilatat, iurgia concitat.

Sed concitare iurgia est peccatum mortale, detestatur enim deus eos qui seminant discordias, ut habetur Prov. VI.

Ergo iactantia est peccatum mortale.

Argumentum 2

Praeterea, omne quod prohibetur in lege dei est peccatum mortale.

Sed super illud Eccli. VI, non te extollas in cogitatione tua, dicit Glossa, iactantiam et superbiam prohibet.

Ergo iactantia est peccatum mortale.

Argumentum 3

Praeterea, iactantia est mendacium quoddam. Non est autem mendacium officiosum vel iocosum. Quod patet ex fine mendacii.

Quia, ut philosophus dicit, in IV ethic., iactator fingit de se maiora existentibus, quandoque nullius gratia, quandoque autem gratia gloriae vel honoris, quandoque autem gratia argenti, et sic patet quod neque est mendacium iocosum, neque officiosum.

Unde relinquitur quod semper sit perniciosum.

Videtur ergo semper esse peccatum mortale.

Sed Contra

Sed contra est quod iactantia oritur ex inani gloria, secundum Gregorium, XXXI Moral..

Sed inanis gloria non semper est peccatum mortale, sed quandoque veniale, quod vitare est valde perfectorum, dicit enim Gregorius quod valde perfectorum est sic ostenso opere auctoris gloriam quaerere ut de illata laude privata nesciant exultatione gaudere.

Ergo iactantia non semper est peccatum mortale.

Corpus

Respondeo dicendum quod, sicut supra dictum est, peccatum mortale est quod caritati contrariatur. Dupliciter ergo iactantia considerari potest. Uno modo, secundum se, prout est mendacium quoddam. Et sic quandoque est peccatum mortale, quandoque veniale. Mortale quidem, quando aliquis iactanter de se profert quod est contra gloriam dei, sicut ex persona regis tyri dicitur Ezech. XXVIII, elevatum est cor tuum, et dixisti, deus ego sum.

Vel etiam contra caritatem proximi, sicut cum aliquis, iactando seipsum, prorumpit in contumelias aliorum; sicut habetur Luc. XVIII de Pharisaeo, qui dicebat, non sum sicut ceteri hominum, raptores, iniusti, adulteri, velut etiam hic publicanus.

Quandoque vero est peccatum veniale, quando scilicet aliquis de se talia iactat quae neque sunt contra deum, neque contra proximum. Alio modo potest considerari secundum suam causam, scilicet superbiam, vel appetitum lucri aut inanis gloriae.

Et sic, si procedat ex superbia vel inani gloria quae sit peccatum mortale, etiam ipsa iactantia erit peccatum mortale.

Alioquin erit peccatum veniale. Sed quando aliquis prorumpit in iactantiam propter appetitum lucri, hoc videtur iam pertinere ad proximi deceptionem et damnum. Et ideo talis iactantia magis est peccatum mortale.

Unde et philosophus dicit, in IV ethic., quod turpior est qui se iactat causa lucri quam qui se iactat causa gloriae vel honoris.

Non tamen semper est peccatum mortale, quia potest esse tale lucrum ex quo alius non damnificatur.

Ad 1

Ad primum ergo dicendum quod ille qui se iactat ad hoc quod iurgia concitet, peccat mortaliter. Sed quandoque contingit quod iactantia est causa iurgiorum non per se, sed per accidens.

Unde ex hoc iactantia non est peccatum mortale.

Ad 2

Ad secundum dicendum quod Glossa illa loquitur de iactantia secundum quod procedit ex superbia prohibita, quae est peccatum mortale.

Ad 3

Ad tertium dicendum quod non semper iactantia importat mendacium perniciosum, sed solum quando est contra caritatem dei aut proximi, aut secundum se aut secundum causam suam. Quod autem aliquis se iactet quasi hoc ipso delectatus, est quiddam vanum, ut philosophus dicit.

Unde reducitur ad mendacium iocosum, nisi forte hoc divinae dilectioni praeferret, ut propter hoc dei praecepta contemneret; sic enim esset contra caritatem dei, in quo solo mens nostra debet quiescere sicut in ultimo fine.

Videtur autem ad mendacium officiosum pertinere cum aliquis ad hoc se iactat ut gloriam vel lucrum acquirat, dummodo hoc sit sine damno aliorum; quia hoc iam pertineret ad mendacium perniciosum.