Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that each act of an unbeliever is a sin. Because a gloss on Rm. 14:23, "All that is not of faith is sin," says: "The whole life of unbelievers is a sin." Now the life of unbelievers consists of their actions. Therefore every action of an unbeliever is a sin.

Objection 2: Further, faith directs the intention. Now there can be no good save what comes from a right intention. Therefore, among unbelievers, no action can be good.

Objection 3: Further, when that which precedes is corrupted, that which follows is corrupted also. Now an act of faith precedes the acts of all the virtues. Therefore, since there is no act of faith in unbelievers, they can do no good work, but sin in every action of theirs.

On the contrary, It is said of Cornelius, while yet an unbeliever (Acts 10:4,31), that his alms were acceptable to God. Therefore not every action of an unbeliever is a sin, but some of his actions are good.

I answer that, As stated above (1.2, Question 85, Articles 2,4) mortal sin takes away sanctifying grace, but does not wholly corrupt the good of nature. Since therefore, unbelief is a mortal sin, unbelievers are without grace indeed, yet some good of nature remains in them. Consequently it is evident that unbelievers cannot do those good works which proceed from grace, viz. meritorious works; yet they can, to a certain extent, do those good works for which the good of nature suffices.

Hence it does not follow that they sin in everything they do; but whenever they do anything out of their unbelief, then they sin. For even as one who has the faith, can commit an actual sin, venial or even mortal, which he does not refer to the end of faith, so too, an unbeliever can do a good deed in a matter which he does not refer to the end of his unbelief.

Reply to Objection 1: The words quoted must be taken to mean either that the life of unbelievers cannot be sinless, since without faith no sin is taken away, or that whatever they do out of unbelief, is a sin. Hence the same authority adds: "Because every one that lives or acts according to his unbelief, sins grievously."

Reply to Objection 2: Faith directs the intention with regard to the supernatural last end: but even the light of natural reason can direct the intention in respect of a connatural good.

Reply to Objection 3: Unbelief does not so wholly destroy natural reason in unbelievers, but that some knowledge of the truth remains in them, whereby they are able to do deeds that are generically good. With regard, however, to Cornelius, it is to be observed that he was not an unbeliever, else his works would not have been acceptable to God, whom none can please without faith. Now he had implicit faith, as the truth of the Gospel was not yet made manifest: hence Peter was sent to him to give him fuller instruction in the faith.

Articulus 4

Argumentum 1

Ad quartum sic proceditur. Videtur quod quaelibet actio infidelis sit peccatum.

Quia super illud Rom. XIV, omne quod non est ex fide peccatum est, dicit Glossa, omnis infidelium vita est peccatum.

Sed ad vitam infidelium pertinet omne quod agunt.

Ergo omnis actio infidelis est peccatum.

Argumentum 2

Praeterea, fides intentionem dirigit. Sed nullum bonum potest esse quod non est ex intentione recta.

Ergo in infidelibus nulla actio potest esse bona.

Argumentum 3

Praeterea, corrupto priori, corrumpuntur posteriora. Sed actus fidei praecedit actus omnium virtutum. Ergo, cum in infidelibus non sit actus fidei, nullum bonum opus facere possunt, sed in omni actu suo peccant.

Sed Contra

Sed contra est quod Cornelio adhuc infideli existenti dictum est quod acceptae erant deo eleemosynae eius.

Ergo non omnis actio infidelis est peccatum, sed aliqua actio eius est bona.

Corpus

Respondeo dicendum quod, sicut supra dictum est, peccatum mortale tollit gratiam gratum facientem, non autem totaliter corrumpit bonum naturae. Unde, cum infidelitas sit quoddam mortale peccatum, infideles quidem gratia carent, remanet tamen in eis aliquod bonum naturae. Unde manifestum est quod infideles non possunt operari opera bona quae sunt ex gratia, scilicet opera meritoria, tamen opera bona ad quae sufficit bonum naturae aliqualiter operari possunt. Unde non oportet quod in omni suo opere peccent, sed quandocumque aliquod opus operantur ex infidelitate, tunc peccant. Sicut enim habens fidem potest aliquod peccatum committere in actu quem non refert ad fidei finem, vel venialiter vel etiam mortaliter peccando; ita etiam infidelis potest aliquem actum bonum facere in eo quod non refert ad finem infidelitatis.

Ad 1

Ad primum ergo dicendum quod verbum illud est intelligendum vel quia vita infidelium non potest esse sine peccato, cum peccata sine fide non tollantur. Vel quia quidquid agunt ex infidelitate peccatum est.

Unde ibi subditur, quia omnis infideliter vivens vel agens vehementer peccat.

Ad 2

Ad secundum dicendum quod fides dirigit intentionem respectu finis ultimi supernaturalis. Sed lumen etiam naturalis rationis potest dirigere intentionem respectu alicuius boni connaturalis.

Ad 3

Ad tertium dicendum quod per infidelitatem non corrumpitur totaliter in infidelibus ratio naturalis, quin remaneat in eis aliqua veri cognitio, per quam possunt facere aliquod opus de genere bonorum.

De Cornelio tamen sciendum est quod infidelis non erat, alioquin eius operatio accepta non fuisset deo, cui sine fide nullus potest placere. Habebat autem fidem implicitam, nondum manifestata evangelii veritate. Unde ut eum in fide plene instrueret, mittitur ad eum Petrus.