Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that sin cannot be in the reason. For the sin of any power is a defect thereof. But the fault of the reason is not a sin, on the contrary, it excuses sin: for a man is excused from sin on account of ignorance. Therefore sin cannot be in the reason.

Objection 2: Further, the primary object of sin is the will, as stated above (Article 1). Now reason precedes the will, since it directs it. Therefore sin cannot be in the reason.

Objection 3: Further, there can be no sin except about things which are under our control. Now perfection and defect of reason are not among those things which are under our control: since by nature some are mentally deficient, and some shrewd-minded. Therefore no sin is in the reason.

On the contrary, Augustine says (De Trin. xii, 12) that sin is in the lower and in the higher reason.

I answer that, The sin of any power is an act of that power, as we have clearly shown (Articles 1,2,3). Now reason has a twofold act: one is its proper act in respect of its proper object, and this is the act of knowing the truth; the other is the act of reason as directing the other powers. Now in both of these ways there may be sin in the reason. First, in so far as it errs in the knowledge of truth, which error is imputed to the reason as a sin, when it is in ignorance or error about what it is able and ought to know: secondly, when it either commands the inordinate movements of the lower powers, or deliberately fails to check them.

Reply to Objection 1: This argument considers the defect in the proper act of the reason in respect of its proper object, and with regard to the case when it is a defect of knowledge about something which one is unable to know: for then this defect of reason is not a sin, and excuses from sin, as is evident with regard to the actions of madmen. If, however, the defect of reason be about something which a man is able and ought to know, he is not altogether excused from sin, and the defect is imputed to him as a sin. The defect which belongs only to the act of directing the other powers, is always imputed to reason as a sin, because it can always obviate this defect by means of its proper act.

Reply to Objection 2: As stated above (Question 17, Article 1), when we were treating of the acts of the will and reason, the will moves and precedes the reason, in one way, and the reason moves and precedes the will in another: so that both the movement of the will can be called rational, and the act of the reason, voluntary. Accordingly sin is found in the reason, either through being a voluntary defect of the reason, or through the reason being the principle of the will's act.

The Reply to the Third Objection is evident from what has been said (ad 1).

Articulus 5

Argumentum 1

Ad quintum sic proceditur. Videtur quod peccatum non possit esse in ratione. Cuiuslibet enim potentiae peccatum est aliquis defectus ipsius. Sed defectus rationis non est peccatum, sed magis excusat peccatum, excusatur enim aliquis a peccato propter ignorantiam. Ergo in ratione non potest esse peccatum.

Argumentum 2

Praeterea, primum subiectum peccati est voluntas, ut dictum est.

Sed ratio praecedit voluntatem, cum sit directiva ipsius.

Ergo peccatum esse non potest in ratione.

Argumentum 3

Praeterea, non potest esse peccatum nisi circa ea quae sunt in nobis. Sed perfectio et defectus rationis non est eorum quae sunt in nobis, quidam enim sunt naturaliter ratione deficientes, vel ratione solertes. Ergo in ratione non est peccatum.

Sed Contra

Sed contra est quod Augustinus dicit, in libro XII de Trin., quod peccatum est in ratione inferiori et in ratione superiori.

Corpus

Respondeo dicendum quod peccatum cuiuslibet potentiae consistit in actu ipsius, sicut ex dictis patet.

Habet autem ratio duplicem actum, unum quidem secundum se, in comparatione ad proprium obiectum, quod est cognoscere aliquod verum; alius autem actus rationis est inquantum est directiva aliarum virium. Utroque igitur modo contingit esse peccatum in ratione. Et primo quidem, inquantum errat in cognitione veri, quod quidem tunc imputatur ei ad peccatum, quando habet ignorantiam vel errorem circa id quod potest et debet scire. Secundo, quando inordinatos actus inferiorum virium vel imperat, vel etiam post deliberationem non coercet.

Ad 1

Ad primum ergo dicendum quod ratio illa procedit de defectu rationis qui pertinet ad actum proprium respectu proprii obiecti, et hoc quando est defectus cognitionis eius quod quis non potest scire. Tunc enim talis defectus rationis non est peccatum, sed excusat a peccato, sicut patet in his quae per furiosos committuntur. Si vero sit defectus rationis circa id quod homo potest et debet scire, non omnino homo excusatur a peccato, sed ipse defectus imputatur ei ad peccatum. Defectus autem qui est solum in dirigendo alias vires, semper imputatur ei ad peccatum, quia huic defectui occurrere potest per proprium actum.

Ad 2

Ad secundum dicendum quod, sicut supra dictum est, cum de actibus voluntatis et rationis ageretur, voluntas quodammodo movet et praecedit rationem, et ratio quodammodo voluntatem, unde et motus voluntatis dici potest rationalis, et actus rationis potest dici voluntarius. Et secundum hoc in ratione invenitur peccatum, vel prout est defectus eius voluntarius, vel prout actus rationis est principium actus voluntatis.

Ad 3

Ad tertium patet responsio ex dictis.