Thomas Aquinas, Summa Theologiae

Objection 1: It seems that a good or wicked angel can sin venially. Because man agrees with the angels in the higher part of his soul which is called the mind, according to Gregory, who says (Hom. xxix in Evang.) that "man understands in common with the angels." But man can commit a venial sin in the higher part of his soul. Therefore an angel can commit a venial sin also.

Objection 2: Further, He that can do more can do less. But an angel could love a created good more than God, and he did, by sinning mortally. Therefore he could also love a creature less than God inordinately, by sinning venially.

Objection 3: Further, wicked angels seem to do things which are venial sins generically, by provoking men to laughter, and other like frivolities. Now the circumstance of the person does not make a mortal sin to be venial as stated above (Article 3), unless there is a special prohibition, which is not the case in point. Therefore an angel can sin venially.

On the contrary, The perfection of an angel is greater than that of man in the primitive state. But man could not sin venially in the primitive state, and much less, therefore, can an angel.

I answer that, An angel's intellect, as stated above in the 1, Question 58, Article 3; 1, Question 79, Article 8, is not discursive, i.e. it does not proceed from principles to conclusions, so as to understand both separately, as we do. Consequently, whenever the angelic intellect considers a conclusion, it must, of necessity, consider it in its principles. Now in matters of appetite, as we have often stated (Question 8, Article 2; Question 10, Article 1; Question 72, Article 5), ends are like principles, while the means are like conclusions. Wherefore, an angel's mind is not directed to the means, except as they stand under the order to the end. Consequently, from their very nature, they can have no inordinateness in respect of the means, unless at the same time they have an inordinateness in respect of the end, and this is a mortal sin. Now good angels are not moved to the means, except in subordination to the due end which is God: wherefore all their acts are acts of charity, so that no venial sin can be in them. On the other hand, wicked angels are moved to nothing except in subordination to the end which is their sin of pride. Therefore they sin mortally in everything that they do of their own will. This does not apply to the appetite for the natural good, which appetite we have stated to be in them (1, Question 63, Article 4; Question 64, Article 2, ad 5).

Reply to Objection 1: Man does indeed agree with the angels in the mind or intellect, but he differs in his mode of understanding, as stated above.

Reply to Objection 2: An angel could not love a creature less than God, without, at the same time, either referring it to God, as the last end, or to some inordinate end, for the reason given above.

Reply to Objection 3: The demons incite man to all such things which seem venial, that he may become used to them, so as to lead him on to mortal sin. Consequently in all such things they sin mortally, on account of the end they have in view.

Articulus 4

Argumentum 1

Ad quartum sic proceditur. Videtur quod Angelus bonus vel malus possit peccare venialiter. Homo enim cum Angelis convenit in superiori animae parte, quae mens vocatur; secundum illud Gregorii, in homil., homo intelligit cum Angelis.

Sed homo secundum superiorem partem animae potest peccare venialiter. Ergo et Angelus.

Argumentum 2

Praeterea, quicumque potest quod est plus, potest etiam quod est minus. Sed Angelus potuit diligere bonum creatum plus quam deum, quod fecit peccando mortaliter. Ergo etiam potuit bonum creatum diligere infra deum inordinate, venialiter peccando.

Argumentum 3

Praeterea, Angeli mali videntur aliqua facere quae sunt ex genere suo venialia peccata, provocando homines ad risum, et ad alias huiusmodi levitates. Sed circumstantia personae non facit de veniali mortale, ut dictum est, nisi speciali prohibitione superveniente, quod non est in proposito.

Ergo Angelus potest peccare venialiter.

Sed Contra

Sed contra est quod maior est perfectio Angeli quam perfectio hominis in primo statu.

Sed homo in primo statu non potuit peccare venialiter.

Ergo multo minus Angelus.

Corpus

Respondeo dicendum quod intellectus Angeli, sicut in primo dictum est, non est discursivus, ut scilicet procedat a principiis in conclusiones, seorsum utrumque intelligens, sicut in nobis contingit. Unde oportet quod quandocumque considerat conclusiones, consideret eas prout sunt in principiis. In appetibilibus autem, sicut multoties dictum est, fines sunt sicut principia; ea vero quae sunt ad finem, sunt sicut conclusiones. Unde mens Angeli non fertur in ea quae sunt ad finem, nisi secundum quod constant sub ordine finis. Propter hoc ex natura sua habent quod non possit in eis esse deordinatio circa ea quae sunt ad finem, nisi simul sit deordinatio circa finem ipsum, quod est per peccatum mortale. Sed Angeli boni non moventur in ea quae sunt ad finem, nisi in ordine ad finem debitum, qui est deus.

Et propter hoc omnes eorum actus sunt actus caritatis. Et sic in eis non potest esse peccatum veniale. Angeli vero mali in nihil moventur nisi in ordine ad finem peccati superbiae ipsorum.

Et ideo in omnibus peccant mortaliter, quaecumque propria voluntate agunt. Secus autem est de appetitu naturalis boni qui est in eis, ut in primo dictum est.

Ad 1

Ad primum ergo dicendum quod homo convenit quidem cum Angelis in mente, sive in intellectu; sed differt in modo intelligendi, ut dictum est.

Ad 2

Ad secundum dicendum quod Angelus non potuit minus diligere creaturam quam deum, nisi simul referens eam in deum, sicut in ultimum finem, vel aliquem finem inordinatum, ratione iam dicta.

Ad 3

Ad tertium dicendum quod omnia illa quae videntur esse venialia, Daemones procurant ut homines ad sui familiaritatem attrahant, et sic deducant eos in peccatum mortale. Unde in omnibus talibus mortaliter peccant, propter intentionem finis.