Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that the act of the sensitive appetite is not commanded. For the Apostle says (Rm. 7:15): "For I do not that good which I will": and a gloss explains this by saying that man lusts, although he wills not to lust. But to lust is an act of the sensitive appetite. Therefore the act of the sensitive appetite is not subject to our command.

Objection 2: Further, corporeal matter obeys God alone, to the effect of formal transmutation, as was shown in the 1, Question 65, Article 4; 1, Question 91, Article 2; 1, Question 110, Article 2. But the act of the sensitive appetite is accompanied by a formal transmutation of the body, consisting in heat or cold. Therefore the act of the sensitive appetite is not subject to man's command.

Objection 3: Further, the proper motive principle of the sensitive appetite is something apprehended by sense or imagination. But it is not always in our power to apprehend something by sense or imagination. Therefore the act of the sensitive appetite is not subject to our command.

On the contrary, Gregory of Nyssa says: "That which obeys reason is twofold, the concupiscible and the irascible," which belong to the sensitive appetite. Therefore the act of the sensitive appetite is subject to the command of reason.

I answer that, An act is subject to our command, in so far as it is in our power, as stated above (Article 5). Consequently in order to understand in what manner the act of the sensitive appetite is subject to the command of reason, we must consider in what manner it is in our power. Now it must be observed that the sensitive appetite differs from the intellective appetite, which is called the will, in the fact that the sensitive appetite is a power of a corporeal organ, whereas the will is not. Again, every act of a power that uses a corporeal organ, depends not only on a power of the soul, but also on the disposition of that corporeal organ: thus the act of vision depends on the power of sight, and on the condition of the eye, which condition is a help or a hindrance to that act. Consequently the act of the sensitive appetite depends not only on the appetitive power, but also on the disposition of the body.

Now whatever part the power of the soul takes in the act, follows apprehension. And the apprehension of the imagination, being a particular apprehension, is regulated by the apprehension of reason, which is universal; just as a particular active power is regulated by a universal active power. Consequently in this respect the act of the sensitive appetite is subject to the command of reason. On the other hand, condition or disposition of the body is not subject to the command of reason: and consequently in this respect, the movement of the sensitive appetite is hindered from being wholly subject to the command of reason.

Moreover it happens sometimes that the movement of the sensitive appetite is aroused suddenly in consequence of an apprehension of the imagination of sense. And then such movement occurs without the command of reason: although reason could have prevented it, had it foreseen. Hence the Philosopher says (Polit. i, 2) that the reason governs the irascible and concupiscible not by a "despotic supremacy," which is that of a master over his slave; but by a "politic and royal supremacy," whereby the free are governed, who are not wholly subject to command.

Reply to Objection 1: That man lusts, although he wills not to lust, is due to a disposition of the body, whereby the sensitive appetite is hindered from perfect compliance with the command of reason. Hence the Apostle adds (Rm. 7:15): "I see another law in my members, fighting against the law of my mind." This may also happen through a sudden movement of concupiscence, as stated above.

Reply to Objection 2: The condition of the body stands in a twofold relation to the act of the sensitive appetite. First, as preceding it: thus a man may be disposed in one way or another, in respect of his body, to this or that passion. Secondly, as consequent to it: thus a man becomes heated through anger. Now the condition that precedes, is not subject to the command of reason: since it is due either to nature, or to some previous movement, which cannot cease at once. But the condition that is consequent, follows the command of reason: since it results from the local movement of the heart, which has various movements according to the various acts of the sensitive appetite.

Reply to Objection 3: Since the external sensible is necessary for the apprehension of the senses, it is not in our power to apprehend anything by the senses, unless the sensible be present; which presence of the sensible is not always in our power. For it is then that man can use his senses if he will so to do; unless there be some obstacle on the part of the organ. On the other hand, the apprehension of the imagination is subject to the ordering of reason, in proportion to the strength or weakness of the imaginative power. For that man is unable to imagine the things that reason considers, is either because they cannot be imagined, such as incorporeal things; or because of the weakness of the imaginative power, due to some organic indisposition.

Articulus 7

Argumentum 1

Ad septimum sic proceditur. Videtur quod actus sensitivi appetitus non sit imperatus.

Dicit enim apostolus, Rom. VII, non enim quod volo bonum, hoc ago, et Glossa exponit quod homo vult non concupiscere, et tamen concupiscit.

Sed concupiscere est actus appetitus sensitivi.

Ergo actus appetitus sensitivi non subditur imperio nostro.

Argumentum 2

Praeterea, materia corporalis soli deo obedit, quantum ad transmutationem formalem, ut in primo habitum est.

Sed actus appetitus sensitivi habet quandam formalem transmutationem corporis, scilicet calorem vel frigus. Ergo actus appetitus sensitivi non subditur imperio humano.

Argumentum 3

Praeterea, proprium motivum appetitus sensitivi est apprehensum secundum sensum vel imaginationem. Sed non est in potestate nostra semper quod aliquid apprehendamus sensu vel imaginatione.

Ergo actus appetitus sensitivi non subiacet imperio nostro.

Sed Contra

Sed contra est quod Gregorius Nyssenus dicit, quod obediens rationi dividitur in duo, in desiderativum et irascitivum, quae pertinent ad appetitum sensitivum.

Ergo actus appetitus sensitivi subiacet imperio rationis.

Corpus

Respondeo dicendum quod secundum hoc aliquis actus imperio nostro subiacet, prout est in potestate nostra, ut supra dictum est.

Et ideo ad intelligendum qualiter actus appetitus sensitivi subdatur imperio rationis, oportet considerare qualiter sit in potestate nostra. Est autem sciendum quod appetitus sensitivus in hoc differt ab appetitu intellectivo, qui dicitur voluntas, quod appetitus sensitivus est virtus organi corporalis, non autem voluntas. Omnis autem actus virtutis utentis organo corporali, dependet non solum ex potentia animae, sed etiam ex corporalis organi dispositione, sicut visio ex potentia visiva, et qualitate oculi, per quam iuvatur vel impeditur. Unde et actus appetitus sensitivi non solum dependet ex VI appetitiva, sed etiam ex dispositione corporis. Illud autem quod est ex parte potentiae animae, sequitur apprehensionem. Apprehensio autem imaginationis, cum sit particularis, regulatur ab apprehensione rationis, quae est universalis, sicut virtus activa particularis a virtute activa universali. Et ideo ex ista parte, actus appetitus sensitivi subiacet imperio rationis. Qualitas autem et dispositio corporis non subiacet imperio rationis. Et ideo ex hac parte, impeditur quin motus sensitivi appetitus totaliter subdatur imperio rationis. Contingit etiam quandoque quod motus appetitus sensitivi subito concitatur ad apprehensionem imaginationis vel sensus. Et tunc ille motus est praeter imperium rationis, quamvis potuisset impediri a ratione, si praevidisset. Unde philosophus dicit, in I polit., quod ratio praeest irascibili et concupiscibili non principatu despotico, qui est domini ad servum; sed principatu politico aut regali, qui est ad liberos, qui non totaliter subduntur imperio.

Ad 1

Ad primum ergo dicendum quod hoc quod homo vult non concupiscere, et tamen concupiscit, contingit ex dispositione corporis, per quam impeditur appetitus sensitivus ne totaliter sequatur imperium rationis.

Unde et apostolus ibidem subdit, video aliam legem in membris meis, repugnantem legi mentis meae.

Hoc etiam contingit propter subitum motum concupiscentiae, ut dictum est.

Ad 2

Ad secundum dicendum quod qualitas corporalis dupliciter se habet ad actum appetitus sensitivi. Uno modo, ut praecedens, prout aliquis est aliqualiter dispositus secundum corpus, ad hanc vel illam passionem. Alio modo, ut consequens, sicut cum ex ira aliquis incalescit. Qualitas igitur praecedens non subiacet imperio rationis, quia vel est ex natura, vel ex aliqua praecedenti motione, quae non statim quiescere potest. Sed qualitas consequens sequitur imperium rationis, quia sequitur motum localem cordis, quod diversimode movetur secundum diversos actus sensitivi appetitus.

Ad 3

Ad tertium dicendum quod, quia ad apprehensionem sensus requiritur sensibile exterius, non est in potestate nostra apprehendere aliquid sensu, nisi sensibili praesente; cuius praesentia non semper est in potestate nostra. Tunc enim homo potest uti sensu cum voluerit, nisi sit impedimentum ex parte organi. Apprehensio autem imaginationis subiacet ordinationi rationis, secundum modum virtutis vel debilitatis imaginativae potentiae. Quod enim homo non possit imaginari quae ratio considerat, contingit vel ex hoc quod non sunt imaginabilia, sicut incorporalia; vel propter debilitatem virtutis imaginativae, quae est ex aliqua indispositione organi.