Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that unbelief is not in the intellect as its subject. For every sin is in the will, according to Augustine (De Duabus Anim. x, xi). Now unbelief is a sin, as stated above (Article 1). Therefore unbelief resides in the will and not in the intellect.

Objection 2: Further, unbelief is sinful through contempt of the preaching of the faith. But contempt pertains to the will. Therefore unbelief is in the will.

Objection 3: Further, a gloss on 2 Cor. 11:14 "Satan . . . transformeth himself into an angel of light," says that if "a wicked angel pretend to be a good angel, and be taken for a good angel, it is not a dangerous or an unhealthy error, if he does or says what is becoming to a good angel." This seems to be because of the rectitude of the will of the man who adheres to the angel, since his intention is to adhere to a good angel. Therefore the sin of unbelief seems to consist entirely in a perverse will: and, consequently, it does not reside in the intellect.

On the contrary, Things which are contrary to one another are in the same subject. Now faith, to which unbelief is opposed, resides in the intellect. Therefore unbelief also is in the intellect.

I answer that, As stated above (1.2, Question 74, Articles 1,2), sin is said to be in the power which is the principle of the sinful act. Now a sinful act may have two principles: one is its first and universal principle, which commands all acts of sin; and this is the will, because every sin is voluntary. The other principle of the sinful act is the proper and proximate principle which elicits the sinful act: thus the concupiscible is the principle of gluttony and lust, wherefore these sins are said to be in the concupiscible. Now dissent, which is the act proper to unbelief, is an act of the intellect, moved, however, by the will, just as assent is.

Therefore unbelief, like faith, is in the intellect as its proximate subject. But it is in the will as its first moving principle, in which way every sin is said to be in the will.

Hence the Reply to the First Objection is clear.

Reply to Objection 2: The will's contempt causes the intellect's dissent, which completes the notion of unbelief. Hence the cause of unbelief is in the will, while unbelief itself is in the intellect.

Reply to Objection 3: He that believes a wicked angel to be a good one, does not dissent from a matter of faith, because "his bodily senses are deceived, while his mind does not depart from a true and right judgment" as the gloss observes . But, according to the same authority, to adhere to Satan when he begins to invite one to his abode, i.e. wickedness and error, is not without sin.

Articulus 2

Argumentum 1

Ad secundum sic proceditur. Videtur quod infidelitas non sit in intellectu sicut in subiecto.

Omne enim peccatum in voluntate est, ut Augustinus dicit, in libro de duabus anim..

Sed infidelitas est quoddam peccatum, ut dictum est.

Ergo infidelitas est in voluntate, non in intellectu.

Argumentum 2

Praeterea, infidelitas habet rationem peccati ex eo quod praedicatio fidei contemnitur. Sed contemptus ad voluntatem pertinet. Ergo infidelitas est in voluntate.

Argumentum 3

Praeterea, II ad Cor. XI, super illud, ipse Satanas transfigurat se in Angelum lucis, dicit Glossa quod, si Angelus malus se bonum fingat, etiam si credatur bonus, non est error periculosus aut morbidus, si facit vel dicit quae bonis Angelis congruunt.

Cuius ratio esse videtur propter rectitudinem voluntatis eius qui ei inhaeret intendens bono Angelo adhaerere. Ergo totum peccatum infidelitatis esse videtur in perversa voluntate.

Non ergo est in intellectu sicut in subiecto.

Sed Contra

Sed contra, contraria sunt in eodem subiecto. Sed fides, cui contrariatur infidelitas, est in intellectu sicut in subiecto. Ergo et infidelitas in intellectu est.

Corpus

Respondeo dicendum quod, sicut supra dictum est, peccatum dicitur esse in illa potentia quae est principium actus peccati. Actus autem peccati potest habere duplex principium. Unum quidem primum et universale, quod imperat omnes actus peccatorum, et hoc principium est voluntas, quia omne peccatum est voluntarium. Aliud autem principium actus peccati est proprium et proximum, quod elicit peccati actum, sicut concupiscibilis est principium gulae et luxuriae, et secundum hoc gula et luxuria dicuntur esse in concupiscibili. Dissentire autem, qui est proprius actus infidelitatis, est actus intellectus, sed moti a voluntate, sicut et assentire. Et ideo infidelitas, sicut et fides, est quidem in intellectu sicut in proximo subiecto, in voluntate autem sicut in primo motivo. Et hoc modo dicitur omne peccatum esse in voluntate.

Ad 1

Unde patet responsio ad primum.

Ad 2

Ad secundum dicendum quod contemptus voluntatis causat dissensum intellectus, in quo perficitur ratio infidelitatis.

Unde causa infidelitatis est in voluntate, sed ipsa infidelitas est in intellectu.

Ad 3

Ad tertium dicendum quod ille qui credit malum Angelum esse bonum non dissentit ab eo quod est fidei, quia sensus corporis fallitur, mens vero non removetur a vera rectaque sententia, ut ibidem dicit Glossa.

Sed si aliquis Satanae adhaereret cum incipit ad sua ducere, idest ad mala et falsa, tunc non careret peccato, ut ibidem dicitur.