Summa Theologica, by St. Thomas Aquinas, [1947], at sacred-texts.com
We must now consider consent; concerning which there are four points of inquiry:
(1) Whether consent is an act of the appetitive or of the apprehensive power?
(2) Whether it is to be found in irrational animals?
(3) Whether it is directed to the end or to the means?
(4) Whether consent to an act belongs to the higher part of the soul only?
Objection 1: It would seem that consent belongs only to the apprehensive part of the soul. For Augustine (De Trin. xii, 12) ascribes consent to the higher reason. But the reason is an apprehensive power. Therefore consent belongs to an apprehensive power.
Objection 2: Further, consent is "co-sense." But sense is an apprehensive power. Therefore consent is the act of an apprehensive power.
Objection 3: Further, just as assent is an application of the intellect to something, so is consent. But assent belongs to the intellect, which is an apprehensive power. Therefore consent also belongs to an apprehensive power.
On the contrary, Damascene says (De Fide Orth. ii, 22) that "if a man judge without affection for that of which he judges, there is no sentence," i.e. consent. But affection belongs to the appetitive power. Therefore consent does also.
I answer that, Consent implies application of sense to something. Now it is proper to sense to take cognizance of things present; for the imagination apprehends the similitude of corporeal things, even in the absence of the things of which they bear the likeness; while the intellect apprehends universal ideas, which it can apprehend indifferently, whether the singulars be present or absent. And since the act of an appetitive power is a kind of inclination to the thing itself, the application of the appetitive power to the thing, in so far as it cleaves to it, gets by a kind of similitude, the name of sense, since, as it were, it acquires direct knowledge of the thing to which it cleaves, in so far as it takes complacency in it. Hence it is written (Wis. 1:1): "Think of [Sentite] the Lord in goodness." And on these grounds consent is an act of the appetitive power.
Reply to Objection 1: As stated in De Anima iii, 9, "the will is in the reason." Hence, when Augustine ascribes consent to the reason, he takes reason as including the will.
Reply to Objection 2: Sense, properly speaking, belongs to the apprehensive faculty; but by way of similitude, in so far as it implies seeking acquaintance, it belongs to the appetitive power, as stated above.
Reply to Objection 3: "Assentire" [to assent] is, to speak, "ad aliud sentire" [to feel towards something]; and thus it implies a certain distance from that to which assent is given. But "consentire" [to consent] is "to feel with," and this implies a certain union to the object of consent. Hence the will, to which it belongs to tend to the thing itself, is more properly said to consent: whereas the intellect, whose act does not consist in a movement towards the thing, but rather the reverse, as we have stated in the FP, Q[16], A[1]; FP, Q[27], A[4]; FP, Q[59], A[2], is more properly said to assent: although one word is wont to be used for the other [*In Latin rather than in English.]. We may also say that the intellect assents, in so far as it is moved by the will.
Objection 1: It would seem that consent is to be found in irrational animals. For consent implies a determination of the appetite to one thing. But the appetite of irrational animals is determinate to one thing. Therefore consent is to be found in irrational animals.
Objection 2: Further, if you remove what is first, you remove what follows. But consent precedes the accomplished act. If therefore there were no consent in irrational animals, there would be no act accomplished; which is clearly false.
Objection 3: Further, men are sometimes said to consent to do something, through some passion; desire, for instance, or anger. But irrational animals act through passion. Therefore they consent.
On the contrary, Damascene says (De Fide Orth. ii, 22) that "after judging, man approves and embraces the judgment of his counselling, and this is called the sentence," i.e. consent. But counsel is not in irrational animals. Therefore neither is consent.
I answer that, Consent, properly speaking, is not in irrational animals. The reason of this is that consent implies an application of the appetitive movement to something as to be done. Now to apply the appetitive movement to the doing of something, belongs to the subject in whose power it is to move the appetite: thus to touch a stone is an action suitable to a stick, but to apply the stick so that it touch the stone, belongs to one who has the power of moving the stick. But irrational animals have not the command of the appetitive movement; for this is in them through natural instinct. Hence in the irrational animal, there is indeed the movement of the appetite, but it does not apply that movement to some particular thing. And hence it is that the irrational animal is not properly said to consent: this is proper to the rational nature, which has the command of the appetitive movement, and is able to apply or not to apply it to this or that thing.
Reply to Objection 1: In irrational animals the determination of the appetite to a particular thing is merely passive: whereas consent implies a determination of the appetite, which is active rather than merely passive.
Reply to Objection 2: If the first be removed, then what follows is removed, provided that, properly speaking, it follow from that only. But if something can follow from several things, it is not removed by the fact that one of them is removed; thus if hardening is the effect of heat and of cold (since bricks are hardened by the fire, and frozen water is hardened by the cold), then by removing heat it does not follow that there is no hardening. Now the accomplishment of an act follows not only from consent, but also from the impulse of the appetite, such as is found in irrational animals.
Reply to Objection 3: The man who acts through passion is able not to follow the passion: whereas irrational animals have not that power. Hence the comparison fails.
Objection 1: It would seem that consent is directed to the end. Because that on account of which a thing is such is still more such. But it is on account of the end that we consent to the means. Therefore, still more do we consent to the end.
Objection 2: Further, the act of the intemperate man is his end, just as the act of the virtuous man is his end. But the intemperate man consents to his own act. Therefore consent can be directed to the end.
Objection 3: Further, desire of the means is choice, as stated above (Q[13], A[1]). If therefore consent were only directed to the means it would nowise differ from choice. And this is proved to be false by the authority of Damascene who says (De Fide Orth. ii, 22) that "after the approval" which he calls "the sentence," "comes the choice." Therefore consent is not only directed to the means.
On the contrary, Damascene says (De Fide Orth. ii, 22) that the "sentence," i.e. the consent, takes place "when a man approves and embraces the judgment of his counsel." But counsel is only about the means. Therefore the same applies to consent.
I answer that, Consent is the application of the appetitive movement to something that is already in the power of him who causes the application. Now the order of action is this: First there is the apprehension of the end; then the desire of the end; then the counsel about the means; then the desire of the means. Now the appetite tends to the last end naturally: wherefore the application of the appetitive movement to the apprehended end has not the nature of consent, but of simple volition. But as to those things which come under consideration after the last end, in so far as they are directed to the end, they come under counsel: and so counsel can be applied to them, in so far as the appetitive movement is applied to the judgment resulting from counsel. But the appetitive movement to the end is not applied to counsel: rather is counsel applied to it, because counsel presupposes the desire of the end. On the other hand, the desire of the means presupposes the decision of counsel. And therefore the application of the appetitive movement to counsel's decision is consent, properly speaking. Consequently, since counsel is only about the means, consent, properly speaking, is of nothing else but the means.
Reply to Objection 1: Just as the knowledge of conclusions through the principles is science, whereas the knowledge of the principles is not science, but something higher, namely, understanding; so do we consent to the means on account of the end, in respect of which our act is not consent but something greater, namely, volition.
Reply to Objection 2: Delight in his act, rather than the act itself, is the end of the intemperate man, and for sake of this delight he consents to that act.
Reply to Objection 3: Choice includes something that consent has not, namely, a certain relation to something to which something else is preferred: and therefore after consent there still remains a choice. For it may happen that by aid of counsel several means have been found conducive to the end, and through each of these meeting with approval, consent has been given to each: but after approving of many, we have given our preference to one by choosing it. But if only one meets with approval, then consent and choice do not differ in reality, but only in our way of looking at them; so that we call it consent, according as we approve of doing that thing; but choice according as we prefer it to those that do not meet with our approval.
Objection 1: It would seem that consent to the act does not always belong to the higher reason. For "delight follows action, and perfects it, just as beauty perfects youth" [*oion tois akmaiois he hora}--as youthful vigor perfects a man in his prime] (Ethic. x, 4). But consent to delight belongs to the lower reason, as Augustine says (De Trin. xii, 12). Therefore consent to the act does not belong only to the higher reason.
Objection 2: Further, an act to which we consent is said to be voluntary. But it belongs to many powers to produce voluntary acts. Therefore the higher reason is not alone in consenting to the act.
Objection 3: Further, "the higher reason is that which is intent on the contemplation and consultation of things eternal," as Augustine says (De Trin. xii, 7). But man often consents to an act not for eternal, but for temporal reasons, or even on account of some passion of the soul. Therefore consent to an act does not belong to the higher reason alone.
On the contrary, Augustine says (De Trin. xii, 12): "It is impossible for man to make up his mind to commit a sin, unless that mental faculty which has the sovereign power of urging his members to, or restraining them from, act, yield to the evil deed and become its slave."
I answer that, The final decision belongs to him who holds the highest place, and to whom it belongs to judge of the others; for as long as judgment about some matter remains to be pronounced, the final decision has not been given. Now it is evident that it belongs to the higher reason to judge of all: since it is by the reason that we judge of sensible things; and of things pertaining to human principles we judge according to Divine principles, which is the function of the higher reason. Wherefore as long as a man is uncertain whether he resists or not, according to Divine principles, no judgment of the reason can be considered in the light of a final decision. Now the final decision of what is to be done is consent to the act. Therefore consent to the act belongs to the higher reason; but in that sense in which the reason includes the will, as stated above (A[1], ad 1).
Reply to Objection 1: Consent to delight in the work done belongs to the higher reason, as also does consent to the work; but consent to delight in thought belongs to the lower reason, just as to the lower reason it belongs to think. Nevertheless the higher reason exercises judgment on the fact of thinking or not thinking, considered as an action; and in like manner on the delight that results. But in so far as the act of thinking is considered as ordained to a further act, it belongs to the lower reason. For that which is ordained to something else, belongs to a lower art or power than does the end to which it is ordained: hence the art which is concerned with the end is called the master or principal art.
Reply to Objection 2: Since actions are called voluntary from the fact that we consent to them, it does not follow that consent is an act of each power, but of the will which is in the reason, as stated above (A[1], ad 1), and from which the voluntary act is named.
Reply to Objection 3: The higher reason is said to consent not only because it always moves to act, according to the eternal reasons; but also because it fails to dissent according to those same reasons.