Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that venial sin cannot be in the higher reason as such, i.e. as considering the eternal law. For the act of a power is not found to fail except that power be inordinately disposed with regard to its object. Now the object of the higher reason is the eternal law, in respect of which there can be no disorder without mortal sin. Therefore there can be no venial sin in the higher reason as such.

Objection 2: Further, since the reason is a deliberative power, there can be no act of reason without deliberation. Now every inordinate movement in things concerning God, if it be deliberate, is a mortal sin. Therefore venial sin is never in the higher reason as such.

Objection 3: Further, it happens sometimes that a sin which takes us unawares, is a venial sin. Now a deliberate sin is a mortal sin, through the reason, in deliberating, having recourse to some higher good, by acting against which, man sins more grievously; just as when the reason in deliberating about an inordinate pleasurable act, considers that it is contrary to the law of God, it sins more grievously in consenting, than if it only considered that it is contrary to moral virtue. But the higher reason cannot have recourse to any higher tribunal than its own object. Therefore if a movement that takes us unawares is not a mortal sin, neither will the subsequent deliberation make it a mortal sin; which is clearly false. Therefore there can be no venial sin in the higher reason as such.

On the contrary, A sudden movement of unbelief is a venial sin. But it belongs to the higher reason as such. Therefore there can be a venial sin in the higher reason as such.

I answer that, The higher reason regards its own object otherwise than the objects of the lower powers that are directed by the higher reason. For it does not regard the objects of the lower powers, except in so far as it consults the eternal law about them, and so it does not regard them save by way of deliberation. Now deliberate consent to what is a mortal sin in its genus, is itself a mortal sin; and consequently the higher reason always sins mortally, if the acts of the lower powers to which it consents are mortal sins.

With regard to its own object it has a twofold act, viz. simple "intuition," and "deliberation," in respect of which it again consults the eternal law about its own object. But in respect of simple intuition, it can have an inordinate movement about Divine things, as when a man suffers a sudden movement of unbelief. And although unbelief, in its genus, is a mortal sin, yet a sudden movement of unbelief is a venial sin, because there is no mortal sin unless it be contrary to the law of God. Now it is possible for one of the articles of faith to present itself to the reason suddenly under some other aspect, before the eternal law, i.e. the law of God, is consulted, or can be consulted, on the matter; as, for instance, when a man suddenly apprehends the resurrection of the dead as impossible naturally, and rejects it, as soon as he had thus apprehended it, before he has had time to deliberate and consider that this is proposed to our belief in accordance with the Divine law. If, however, the movement of unbelief remains after this deliberation, it is a mortal sin. Therefore, in sudden movements, the higher reason may sin venially in respect of its proper object, even if it be a mortal sin in its genus; or it may sin mortally in giving a deliberate consent; but in things pertaining to the lower powers, it always sins mortally, in things which are mortal sins in their genus, but not in those which are venial sins in their genus.

Reply to Objection 1: A sin which is against the eternal law, though it be mortal in its genus, may nevertheless be venial, on account of the incompleteness of a sudden action, as stated.

Reply to Objection 2: In matters of action, the simple intuition of the principles from which deliberation proceeds, belongs to the reason, as well as the act of deliberation: even as in speculative matters it belongs to the reason both to syllogize and to form propositions: consequently the reason also can have a sudden movement.

Reply to Objection 3: One and the same thing may be the subject of different considerations, of which one is higher than the other; thus the existence of God may be considered, either as possible to be known by the human reason, or as delivered to us by Divine revelation, which is a higher consideration. And therefore, although the object of the higher reason is, in its nature, something sublime, yet it is reducible to some yet higher consideration: and in this way, that which in the sudden movement was not a mortal sin, becomes a mortal sin in virtue of the deliberation which brought it into the light of a higher consideration, as was explained above.

Articulus 10

Argumentum 1

Ad decimum sic proceditur. Videtur quod in superiori ratione non possit esse peccatum veniale secundum seipsam, idest secundum quod inspicit rationes aeternas. Actus enim potentiae non invenitur esse deficiens, nisi per hoc quod inordinate se habet circa suum obiectum. Sed obiectum superioris rationis sunt aeternae rationes, a quibus deordinari non est sine peccato mortali. Ergo in superiori ratione non potest esse peccatum veniale secundum seipsam.

Argumentum 2

Praeterea, cum ratio sit vis deliberativa, actus rationis semper est cum deliberatione. Sed omnis inordinatus motus in his quae dei sunt, si sit cum deliberatione, est peccatum mortale. Ergo in ratione superiori secundum seipsam, nunquam est peccatum veniale.

Argumentum 3

Praeterea, contingit quandoque quod peccatum ex subreptione est peccatum veniale, peccatum autem ex deliberatione est peccatum mortale, per hoc quod ratio deliberans recurrit ad aliquod maius bonum, contra quod homo agens gravius peccat, sicut cum de actu delectabili inordinato ratio deliberat quod est contra legem dei, gravius peccat consentiendo, quam si solum consideraret quod est contra virtutem moralem. Sed ratio superior non potest recurrere ad aliquod altius quam sit suum obiectum. Ergo si motus ex subreptione non sit peccatum mortale, neque etiam deliberatio superveniens faciet ipsum esse peccatum mortale, quod patet esse falsum. Non ergo in ratione superiori secundum seipsam, potest esse peccatum veniale.

Sed Contra

Sed contra, motus subreptitius infidelitatis est peccatum veniale.

Sed pertinet ad superiorem rationem secundum seipsam. Ergo in ratione superiori potest esse peccatum veniale secundum seipsam.

Corpus

Respondeo dicendum quod ratio superior aliter fertur in suum obiectum, atque aliter in obiecta inferiorum virium quae per ipsam diriguntur. In obiecta enim inferiorum virium non fertur nisi inquantum de eis consulit rationes aeternas.

Unde non fertur in ea nisi per modum deliberationis. Deliberatus autem consensus in his quae ex genere suo sunt mortalia, est mortale peccatum. Et ideo ratio superior semper mortaliter peccat, si actus inferiorum virium in quos consentit, sint peccata mortalia. Sed circa proprium obiectum habet duos actus, scilicet simplicem intuitum; et deliberationem, secundum quod etiam de proprio obiecto consulit rationes aeternas.

Secundum autem simplicem intuitum, potest aliquem inordinatum motum habere circa divina, puta cum quis patitur subitum infidelitatis motum. Et quamvis infidelitas secundum suum genus sit peccatum mortale, tamen subitus motus infidelitatis est peccatum veniale. Quia peccatum mortale non est nisi sit contra legem dei, potest autem aliquid eorum quae pertinent ad fidem, subito rationi occurrere sub quadam alia ratione, antequam super hoc consulatur, vel consuli possit, ratio aeterna, idest lex dei; puta cum quis resurrectionem mortuorum subito apprehendit ut impossibilem secundum naturam, et simul apprehendendo renititur, antequam tempus habeat deliberandi quod hoc est nobis traditum ut credendum secundum legem divinam. Si vero post hanc deliberationem motus infidelitatis maneat, est peccatum mortale. Et ideo circa proprium obiectum, etsi sit peccatum mortale ex genere, potest ratio superior peccare venialiter in subitis motibus; vel etiam mortaliter per deliberatum consensum. In his autem quae pertinent ad inferiores vires, semper peccat mortaliter in his quae sunt peccata mortalia ex suo genere, non autem in his quae secundum suum genus sunt venialia peccata.

Ad 1

Ad primum ergo dicendum quod peccatum quod est contra rationes aeternas, etsi sit peccatum mortale ex genere, potest tamen esse peccatum veniale propter imperfectionem actus subiti, ut dictum est.

Ad 2

Ad secundum dicendum quod in operativis ad rationem, ad quam pertinet deliberatio, pertinet etiam simplex intuitus eorum ex quibus deliberatio procedit, sicut etiam in speculativis ad rationem pertinet et syllogizare, et propositiones formare.

Et ideo etiam ratio potest habere subitum motum.

Ad 3

Ad tertium dicendum quod una et eadem res potest diversas considerationes habere, quarum una est altera altior, sicut deum esse potest considerari vel inquantum est cognoscibile ratione humana, vel inquantum creditur revelatione divina, quae est consideratio altior. Et ideo quamvis obiectum rationis superioris sit quiddam secundum naturam rei altissimum, tamen potest etiam reduci in quandam altiorem considerationem. Et hac ratione, quod in motu subito non erat peccatum mortale, per deliberationem reducentem in altiorem considerationem fit peccatum mortale, sicut supra expositum est.