1 Objection 1: It would seem that a beatified angel can sin. For, as was said above Article 7), beatitude does not do away with nature. But it is of the very notion of created nature, that it can fail. Therefore a beatified angel can sin.
1 Ad octavum sic proceditur. Videtur quod Angelus beatus peccare possit. Beatitudo enim non tollit naturam, ut dictum est. Sed de ratione naturae creatae est quod possit deficere. Ergo Angelus beatus potest peccare.
2 Objection 2: Further, the rational powers are referred to opposites, as the Philosopher observes Metaph. iv, text. 3). But the will of the angel in beatitude does not cease to be rational. Therefore it is inclined towards good and evil.
2 Praeterea, potestates rationales sunt ad opposita, ut philosophus dicit. Sed voluntas Angeli beati non desinit esse rationalis. Ergo se habet ad bonum et malum.
3 Objection 3: Further, it belongs to the liberty of free-will for man to be able to choose good or evil. But the freedom of will is not lessened in the beatified angels. Therefore they can sin.
3 Praeterea, ad libertatem arbitrii pertinet quod homo possit eligere bonum et malum. Sed libertas arbitrii non minuitur in Angelis beatis. Ergo possunt peccare.
4 On the contrary, Augustine says Gen. ad lit. xi) that there is in the holy angels that nature which cannot sin. Therefore the holy angels cannot sin.
4 Sed contra est quod Augustinus dicit, XI super Gen. ad Litt., quod illa natura quae peccare non potest in sanctis Angelis est. Ergo sancti Angeli peccare non possunt.
5 I answer that, The beatified angels cannot sin. The reason for this is, because their beatitude consists in seeing God through His essence. Now, God's essence is the very essence of goodness. Consequently the angel beholding God is disposed towards God in the same way as anyone else not seeing God is to the common form of goodness. Now it is impossible for any man either to will or to do anything except aiming at what is good; or for him to wish to turn away from good precisely as such. Therefore the beatified angel can neither will nor act, except as aiming towards God. Now whoever wills or acts in this manner cannot sin. Consequently the beatified angel cannot sin.
5 Respondeo dicendum quod Angeli beati peccare non possunt. Cuius ratio est, quia eorum beatitudo in hoc consistit, quod per essentiam Deum vident. Essentia autem Dei est ipsa essentia bonitatis. Unde hoc modo se habet Angelus videns Deum ad ipsum Deum, sicut se habet quicumque non videns Deum ad communem rationem boni. Impossibile est autem quod aliquis quidquam velit vel operetur, nisi attendens ad bonum; vel quod velit divertere a bono, inquantum huiusmodi. Angelus igitur beatus non potest velle vel agere, nisi attendens ad Deum. Sic autem volens vel agens non potest peccare. Unde Angelus beatus nullo modo peccare potest.
6 Reply to Objection 1: Created good, considered in itself, can fail. But from its perfect union with the uncreated good, such as is the union of beatitude, it is rendered unable to sin, for the reason already alleged.
6 Ad primum ergo dicendum quod bonum creatum, in se consideratum, deficere potest. Sed ex coniunctione perfecta ad bonum increatum, qualis est coniunctio beatitudinis, adipiscitur quod peccare non possit, ratione iam dicta.
7 Reply to Objection 2: The rational powers are referred to opposites in the things to which they are not inclined naturally; but as to the things whereunto they have a natural tendency, they are not referred to opposites. For the intellect cannot but assent to naturally known principles; in the same way, the will cannot help clinging to good, formally as good; because the will is naturally ordained to good as to its proper object. Consequently the will of the angels is referred to opposites, as to doing many things, or not doing them. But they have no tendency to opposites with regard to God Himself, Whom they see to be the very nature of goodness; but in all things their aim is towards God, which ever alternative they choose, that is not sinful.
7 Ad secundum dicendum quod virtutes rationales se habent ad opposita in illis ad quae non ordinantur naturaliter, sed quantum ad illa ad quae naturaliter ordinantur, non se habent ad opposita. Intellectus enim non potest non assentire principiis naturaliter notis, et similiter voluntas non potest non adhaerere bono inquantum est bonum, quia in bonum naturaliter ordinatur sicut in suum obiectum. Voluntas igitur Angeli se habet ad opposita, quantum ad multa facienda vel non facienda. Sed quantum ad ipsum Deum, quem vident esse ipsam essentiam bonitatis, non se habent ad opposita; sed secundum ipsum ad omnia diriguntur, quodcumque oppositorum eligant. Quod sine peccato est.
8 Reply to Objection 3: Free-will in its choice of means to an end is disposed just as the intellect is to conclusions. Now it is evident that it belongs to the power of the intellect to be able to proceed to different conclusions, according to given principles; but for it to proceed to some conclusion by passing out of the order of the principles, comes of its own defect. Hence it belongs to the perfection of its liberty for the free-will to be able to choose between opposite things, keeping the order of the end in view; but it comes of the defect of liberty for it to choose anything by turning away from the order of the end; and this is to sin. Hence there is greater liberty of will in the angels, who cannot sin, than there is in ourselves, who can sin.
8 Ad tertium dicendum quod liberum arbitrium sic se habet ad eligendum ea quae sunt ad finem, sicut se habet intellectus ad conclusiones. Manifestum est autem quod ad virtutem intellectus pertinet, ut in diversas conclusiones procedere possit secundum principia data, sed quod in aliquam conclusionem procedat praetermittendo ordinem principiorum, hoc est ex defectu ipsius. Unde quod liberum arbitrium diversa eligere possit servato ordine finis, hoc pertinet ad perfectionem libertatis eius, sed quod eligat aliquid divertendo ab ordine finis, quod est peccare, hoc pertinet ad defectum libertatis. Unde maior libertas arbitrii est in Angelis, qui peccare non possunt, quam in nobis, qui peccare possumus.