Summa Th. I EN Qu.79 a.13

Article: 13 Whether conscience be a power?




Objection: 1. It would seem that conscience is a power; for Origen says [*Commentary on Rm 2,15] that "conscience is a correcting and guiding spirit accompanying the soul, by which it is led away from evil and made to cling to good." But in the soul, spirit designates a power---either the mind itself, according to the text (Ep 4,13), "Be ye renewed in the spirit of your mind"---or the imagination, whence imaginary vision is called spiritual, as Augustine says (Gn ad lit. xii, 7,24). Therefore conscience is a power.

2. Further, nothing is a subject of sin, except a power of the soul. But conscience is a subject of sin; for it is said of some that "their mind and conscience are defiled" (Titus 1:15). Therefore it seems that conscience is a power.

3. Further, conscience must of necessity be either an act, a habit, or a power. But it is not an act; for thus it would not always exist in man. Nor is it a habit; for conscience is not one thing but many, since we are directed in our actions by many habits of knowledge. Therefore conscience is a power.

On the contrary Conscience can be laid aside. But a power cannot be laid aside. Therefore conscience is not a power.

I answer that, Properly speaking, conscience is not a power, but an act. This is evident both from the very name and from those things which in the common way of speaking are attributed to conscience. For conscience, according to the very nature of the word, implies the relation of knowledge to something: for conscience may be resolved into "cum alio scientia," i.e. knowledge applied to an individual case. But the application of knowledge to something is done by some act. Wherefore from this explanation of the name it is clear that conscience is an act.

The same is manifest from those things which are attributed to conscience. For conscience is said to witness, to bind, or incite, and also to accuse, torment, or rebuke. And all these follow the application of knowledge or science to what we do: which application is made in three ways. One way in so far as we recognize that we have done or not done something; "Thy conscience knoweth that thou hast often spoken evil of others" (Qo 7,23), and according to this, conscience is said to witness. In another way, so far as through the conscience we judge that something should be done or not done; and in this sense, conscience is said to incite or to bind. In the third way, so far as by conscience we judge that something done is well done or ill done, and in this sense conscience is said to excuse, accuse, or torment. Now, it is clear that all these things follow the actual application of knowledge to what we do. Wherefore, properly speaking, conscience denominates an act. But since habit is a principle of act, sometimes the name conscience is given to the first natural habit---namely, 'synderesis': thus Jerome calls 'synderesis' conscience (Gloss. Ez 1,6); Basil [*Hom. in princ. Proverb.], the "natural power of judgment," and Damascene [*De Fide Orth. iv. 22] says that it is the "law of our intellect." For it is customary for causes and effects to be called after one another.

Reply to Objection: 1. Conscience is called a spirit, so far as spirit is the same as mind; because conscience is a certain pronouncement of the mind.

2. The conscience is said to be defiled, not as a subject, but as the thing known is in knowledge; so far as someone knows he is defiled.

3. Although an act does not always remain in itself, yet it always remains in its cause, which is power and habit. Now all the habits by which conscience is formed, although many, nevertheless have their efficacy from one first habit, the habit of first principles, which is called "synderesis." And for this special reason, this habit is sometimes called conscience, as we have said above.



Question: 80 OF THE APPETITIVE POWERS IN GENERAL (TWO ARTICLES)





Next we consider the appetitive powers, concerning which there are four heads of consideration: first, the appetitive powers in general; second, sensuality; third, the will; fourth, the free-will. Under the first there are two points of inquiry:

(1) Whether the appetite should be considered a special power of the soul?

(2) Whether the appetite should be divided into intellectual and sensitive as distinct powers?



Article: 1 Whether the appetite is a special power of the soul?




Objection: 1. It would seem that the appetite is not a special power of the soul. For no power of the soul is to be assigned for those things which are common to animate and to inanimate things. But appetite is common to animate and inanimate things: since "all desire good," as the Philosopher says (Ethic. i, 1). Therefore the appetite is not a special power of the soul.

2. Further, powers are differentiated by their objects. But what we desire is the same as what we know. Therefore the appetitive power is not distinct from the apprehensive power.

3. Further, the common is not divided from the proper. But each power of the soul desires some particular desirable thing---namely its own suitable object. Therefore, with regard to this object which is the desirable in general, we should not assign some particular power distinct from the others, called the appetitive power.

On the contrary The Philosopher distinguishes (De Anima ii, 3) the appetitive from the other powers. Damascene also (De Fide Orth. ii, 22) distinguishes the appetitive from the cognitive powers.

I answer that It is necessary to assign an appetitive power to the soul. To make this evident, we must observe that some inclination follows every form: for example, fire, by its form, is inclined to rise, and to generate its like. Now, the form is found to have a more perfect existence in those things which participate knowledge than in those which lack knowledge. For in those which lack knowledge, the form is found to determine each thing only to its own being---that is, to its nature. Therefore this natural form is followed by a natural inclination, which is called the natural appetite. But in those things which have knowledge, each one is determined to its own natural being by its natural form, in such a manner that it is nevertheless receptive of the species of other things: for example, sense receives the species of all things sensible, and the intellect, of all things intelligible, so that the soul of man is, in a way, all things by sense and intellect: and thereby, those things that have knowledge, in a way, approach to a likeness to God, "in Whom all things pre-exist," as Dionysius says (Div. Nom. v).

Therefore, as forms exist in those things that have knowledge in a higher manner and above the manner of natural forms; so must there be in them an inclination surpassing the natural inclination, which is called the natural appetite. And this superior inclination belongs to the appetitive power of the soul, through which the animal is able to desire what it apprehends, and not only that to which it is inclined by its natural form. And so it is necessary to assign an appetitive power to the soul.

Reply to Objection: 1. Appetite is found in things which have knowledge, above the common manner in which it is found in all things, as we have said above. Therefore it is necessary to assign to the soul a particular power.

2. What is apprehended and what is desired are the same in reality, but differ in aspect: for a thing is apprehended as something sensible or intelligible, whereas it is desired as suitable or good. Now, it is diversity of aspect in the objects, and not material diversity, which demands a diversity of powers.

3. Each power of the soul is a form or nature, and has a natural inclination to something. Wherefore each power desires by the natural appetite that object which is suitable to itself. Above which natural appetite is the animal appetite, which follows the apprehension, and by which something is desired not as suitable to this or that power, such as sight for seeing, or sound for hearing; but simply as suitable to the animal.



Article: 2 Whether the sensitive and intellectual appetites are distinct powers?




Objection: 1. It would seem that the sensitive and intellectual appetites are not distinct powers. For powers are not differentiated by accidental differences, as we have seen above (Question [77], Article [3]). But it is accidental to the appetible object whether it be apprehended by the sense or by the intellect. Therefore the sensitive and intellectual appetites are not distinct powers.

2. Further, intellectual knowledge is of universals; and so it is distinct from sensitive knowledge, which is of individual things. But there is no place for this distinction in the appetitive part: for since the appetite is a movement of the soul to individual things, seemingly every act of the appetite regards an individual thing. Therefore the intellectual appetite is not distinguished from the sensitive.

3. Further, as under the apprehensive power, the appetitive is subordinate as a lower power, so also is the motive power. But the motive power which in man follows the intellect is not distinct from the motive power which in animals follows sense. Therefore, for a like reason, neither is there distinction in the appetitive part.

On the contrary The Philosopher (De Anima iii, 9) distinguishes a double appetite, and says (De Anima iii, 11) that the higher appetite moves the lower.

I answer that We must needs say that the intellectual appetite is a distinct power from the sensitive appetite. For the appetitive power is a passive power, which is naturally moved by the thing apprehended: wherefore the apprehended appetible is a mover which is not moved, while the appetite is a mover moved, as the Philosopher says in De Anima iii, 10 and Metaph. xii (Did. xi, 7). Now things passive and movable are differentiated according to the distinction of the corresponding active and motive principles; because the motive must be proportionate to the movable, and the active to the passive: indeed, the passive power itself has its very nature from its relation to its active principle. Therefore, since what is apprehended by the intellect and what is apprehended by sense are generically different; consequently, the intellectual appetite is distinct from the sensitive.

Reply to Objection: 1. It is not accidental to the thing desired to be apprehended by the sense or the intellect; on the contrary, this belongs to it by its nature; for the appetible does not move the appetite except as it is apprehended. Wherefore differences in the thing apprehended are of themselves differences of the appetible. And so the appetitive powers are distinct according to the distinction of the things apprehended, as their proper objects.

2. The intellectual appetite, though it tends to individual things which exist outside the soul, yet tends to them as standing under the universal; as when it desires something because it is good. Wherefore the Philosopher says (Rhetoric. ii, 4) that hatred can regard a universal, as when "we hate every kind of thief." In the same way by the intellectual appetite we may desire the immaterial good, which is not apprehended by sense, such as knowledge, virtue, and suchlike.



Question: 81 OF THE POWER OF SENSUALITY (THREE ARTICLES)





Next we have to consider the power of sensuality, concerning which there are three points of inquiry:

(1) Whether sensuality is only an appetitive power?

(2) Whether it is divided into irascible and concupiscible as distinct powers?

(3) Whether the irascible and concupiscible powers obey reason?



Article: 1 Whether sensuality is only appetitive?




Objection: 1. It would seem that sensuality is not only appetitive, but also cognitive. For Augustine says (De Trin. xii, 12) that "the sensual movement of the soul which is directed to the bodily senses is common to us and beasts." But the bodily senses belong to the apprehensive powers. Therefore sensuality is a cognitive power.

2. Further, things which come under one division seem to be of one genus. But Augustine (De Trin. xii, 12) divides sensuality against the higher and lower reason, which belong to knowledge. Therefore sensuality also is apprehensive.

3. Further, in man's temptations sensuality stands in the place of the "serpent." But in the temptation of our first parents, the serpent presented himself as one giving information and proposing sin, which belong to the cognitive power. Therefore sensuality is a cognitive power.

On the contrary Sensuality is defined as "the appetite of things belonging to the body."

I answer that The name sensuality seems to be taken from the sensual movement, of which Augustine speaks (De Trin. xii, 12, 13), just as the name of a power is taken from its act; for instance, sight from seeing. Now the sensual movement is an appetite following sensitive apprehension. For the act of the apprehensive power is not so properly called a movement as the act of the appetite: since the operation of the apprehensive power is completed in the very fact that the thing apprehended is in the one that apprehends: while the operation of the appetitive power is completed in the fact that he who desires is borne towards the thing desirable. Therefore the operation of the apprehensive power is likened to rest: whereas the operation of the appetitive power is rather likened to movement. Wherefore by sensual movement we understand the operation of the appetitive power: so that sensuality is the name of the sensitive appetite.

Reply to Objection: 1. By saying that the sensual movement of the soul is directed to the bodily senses, Augustine does not give us to understand that the bodily senses are included in sensuality, but rather that the movement of sensuality is a certain inclination to the bodily senses, since we desire things which are apprehended through the bodily senses. And thus the bodily senses appertain to sensuality as a preamble.

2. Sensuality is divided against higher and lower reason, as having in common with them the act of movement: for the apprehensive power, to which belong the higher and lower reason, is a motive power; as is appetite, to which appertains sensuality.

3. The serpent not only showed and proposed sin, but also incited to the commission of sin. And in this, sensuality is signified by the serpent.



Article: 2 Whether the sensitive appetite is divided into the irascible and concupiscible as distinct powers?




Objection: 1. It would seem that the sensitive appetite is not divided into the irascible and concupiscible as distinct powers. For the same power of the soul regards both sides of a contrariety, as sight regards both black and white, according to the Philosopher (De Anima ii, 11). But suitable and harmful are contraries. Since, then, the concupiscible power regards what is suitable, while the irascible is concerned with what is harmful, it seems that irascible and concupiscible are the same power in the soul.

2. Further, the sensitive appetite regards only what is suitable according to the senses. But such is the object of the concupiscible power. Therefore there is no sensitive appetite differing from the concupiscible.

3. Further, hatred is in the irascible part: for Jerome says on Mt 13,33: "We ought to have the hatred of vice in the irascible power." But hatred is contrary to love, and is in the concupiscible part. Therefore the concupiscible and irascible are the same powers.

On the contrary Gregory of Nyssa (Nemesius, De Natura Hominis) and Damascene (De Fide Orth. ii, 12) assign two parts to the sensitive appetite, the irascible and the concupiscible.

I answer that The sensitive appetite is one generic power, and is called sensuality; but it is divided into two powers, which are species of the sensitive appetite---the irascible and the concupiscible. In order to make this clear, we must observe that in natural corruptible things there is needed an inclination not only to the acquisition of what is suitable and to the avoiding of what is harmful, but also to resistance against corruptive and contrary agencies which are a hindrance to the acquisition of what is suitable, and are productive of harm. For example, fire has a natural inclination, not only to rise from a lower position, which is unsuitable to it, towards a higher position which is suitable, but also to resist whatever destroys or hinders its action. Therefore, since the sensitive appetite is an inclination following sensitive apprehension, as natural appetite is an inclination following the natural form, there must needs be in the sensitive part two appetitive powers---one through which the soul is simply inclined to seek what is suitable, according to the senses, and to fly from what is hurtful, and this is called the concupiscible: and another, whereby an animal resists these attacks that hinder what is suitable, and inflict harm, and this is called the irascible. Whence we say that its object is something arduous, because its tendency is to overcome and rise above obstacles. Now these two are not to be reduced to one principle: for sometimes the soul busies itself with unpleasant things, against the inclination of the concupiscible appetite, in order that, following the impulse of the irascible appetite, it may fight against obstacles. Wherefore also the passions of the irascible appetite counteract the passions of the concupiscible appetite: since the concupiscence, on being aroused, diminishes anger; and anger being roused, diminishes concupiscence in many cases. This is clear also from the fact that the irascible is, as it were, the champion and defender of the concupiscible when it rises up against what hinders the acquisition of the suitable things which the concupiscible desires, or against what inflicts harm, from which the concupiscible flies. And for this reason all the passions of the irascible appetite rise from the passions of the concupiscible appetite and terminate in them; for instance, anger rises from sadness, and having wrought vengeance, terminates in joy. For this reason also the quarrels of animals are about things concupiscible---namely, food and sex, as the Philosopher says [*De Animal. Histor. viii.].

Reply to Objection: 1. The concupiscible power regards both what is suitable and what is unsuitable. But the object of the irascible power is to resist the onslaught of the unsuitable.

2. As in the apprehensive powers of the sensitive part there is an estimative power, which perceives those things which do not impress the senses, as we have said above (Question [78], Article [2]); so also in the sensitive appetite there is a certain appetitive power which regards something as suitable, not because it pleases the senses, but because it is useful to the animal for self-defense: and this is the irascible power.

3. Hatred belongs simply to the concupiscible appetite: but by reason of the strife which arises from hatred, it may belong to the irascible appetite.



Article: 3 Whether the irascible and concupiscible appetites obey reason?




Objection: 1. It would seem that the irascible and concupiscible appetites do not obey reason. For irascible and concupiscible are parts of sensuality. But sensuality does not obey reason, wherefore it is signified by the serpent, as Augustine says (De Trin. xii, 12,13). Therefore the irascible and concupiscible appetites do not obey reason.

2. Further, what obeys a certain thing does not resist it. But the irascible and concupiscible appetites resist reason: according to the Apostle (Rm 7,23): "I see another law in my members fighting against the law of my mind." Therefore the irascible and concupiscible appetites do not obey reason.

3. Further, as the appetitive power is inferior to the rational part of the soul, so also is the sensitive power. But the sensitive part of the soul does not obey reason: for we neither hear nor see just when we wish. Therefore, in like manner, neither do the powers of the sensitive appetite, the irascible and concupscible, obey reason.

On the contrary Damascene says (De Fide Orth. ii, 12) that "the part of the soul which is obedient and amenable to reason is divided into concupiscence and anger."

I answer that In two ways the irascible and concupiscible powers obey the higher part, in which are the intellect or reason, and the will; first, as to reason, secondly as to the will. They obey the reason in their own acts, because in other animals the sensitive appetite is naturally moved by the estimative power; for instance, a sheep, esteeming the wolf as an enemy, is afraid. In man the estimative power, as we have said above (Question [78], Article [4]), is replaced by the cogitative power, which is called by some 'the particular reason,' because it compares individual intentions. Wherefore in man the sensitive appetite is naturally moved by this particular reason. But this same particular reason is naturally guided and moved according to the universal reason: wherefore in syllogistic matters particular conclusions are drawn from universal propositions. Therefore it is clear that the universal reason directs the sensitive appetite, which is divided into concupiscible and irascible; and this appetite obeys it. But because to draw particular conclusions from universal principles is not the work of the intellect, as such, but of the reason: hence it is that the irascible and concupiscible are said to obey the reason rather than to obey the intellect. Anyone can experience this in himself: for by applying certain universal considerations, anger or fear or the like may be modified or excited.

To the will also is the sensitive appetite subject in execution, which is accomplished by the motive power. For in other animals movement follows at once the concupiscible and irascible appetites: for instance, the sheep, fearing the wolf, flees at once, because it has no superior counteracting appetite. On the contrary, man is not moved at once, according to the irascible and concupiscible appetites: but he awaits the command of the will, which is the superior appetite. For wherever there is order among a number of motive powers, the second only moves by virtue of the first: wherefore the lower appetite is not sufficient to cause movement, unless the higher appetite consents. And this is what the Philosopher says (De Anima iii, 11), that "the higher appetite moves the lower appetite, as the higher sphere moves the lower." In this way, therefore, the irascible and concupiscible are subject to reason.

Reply to Objection: 1. Sensuality is signified by the serpent, in what is proper to it as a sensitive power. But the irascible and concupiscible powers denominate the sensitive appetite rather on the part of the act, to which they are led by the reason, as we have said.

2. As the Philosopher says (Polit. i, 2): "We observe in an animal a despotic and a politic principle: for the soul dominates the body by a despotic power; but the intellect dominates the appetite by a politic and royal power." For a power is called despotic whereby a man rules his slaves, who have not the right to resist in any way the orders of the one that commands them, since they have nothing of their own. But that power is called politic and royal by which a man rules over free subjects, who, though subject to the government of the ruler, have nevertheless something of their own, by reason of which they can resist the orders of him who commands. And so, the soul is said to rule the body by a despotic power, because the members of the body cannot in any way resist the sway of the soul, but at the soul's command both hand and foot, and whatever member is naturally moved by voluntary movement, are moved at once. But the intellect or reason is said to rule the irascible and concupiscible by a politic power: because the sensitive appetite has something of its own, by virtue whereof it can resist the commands of reason. For the sensitive appetite is naturally moved, not only by the estimative power in other animals, and in man by the cogitative power which the universal reason guides, but also by the imagination and sense. Whence it is that we experience that the irascible and concupiscible powers do resist reason, inasmuch as we sense or imagine something pleasant, which reason forbids, or unpleasant, which reason commands. And so from the fact that the irascible and concupiscible resist reason in something, we must not conclude that they do not obey.

3. The exterior senses require for action exterior sensible things, whereby they are affected, and the presence of which is not ruled by reason. But the interior powers, both appetitive and apprehensive, do not require exterior things. Therefore they are subject to the command of reason, which can not only incite or modify the affections of the appetitive power, but can also form the phantasms of the imagination.



Question: 82 OF THE WILL (FIVE ARTICLES)





We next consider the will. Under this head there are five points of inquiry:

(1) Whether the will desires something of necessity?

(2) Whether it desires anything of necessity?

(3) Whether it is a higher power than the intellect?

(4) Whether the will moves the intellect?

(5) Whether the will is divided into irascible and concupiscible?



Article: 1 Whether the will desires something of necessity?




Objection: 1. It would seem that the will desires nothing. For Augustine says (De Civ. Dei v, 10) that it anything is necessary, it is not voluntary. But whatever the will desires is voluntary. Therefore nothing that the will desires is desired of necessity.

2. Further, the rational powers, according to the Philosopher (Metaph. viii, 2), extend to opposite things. But the will is a rational power, because, as he says (De Anima iii, 9), "the will is in the reason." Therefore the will extends to opposite things, and therefore it is determined to nothing of necessity.

3. Further, by the will we are masters of our own actions. But we are not masters of that which is of necessity. Therefore the act of the will cannot be necessitated.

On the contrary Augustine says (De Trin. xiii, 4) that "all desire happiness with one will." Now if this were not necessary, but contingent, there would at least be a few exceptions. Therefore the will desires something of necessity.

I answer that The word "necessity" is employed in many ways. For that which must be is necessary. Now that a thing must be may belong to it by an intrinsic principle---either material, as when we say that everything composed of contraries is of necessity corruptible---or formal, as when we say that it is necessary for the three angles of a triangle to be equal to two right angles. And this is "natural" and "absolute necessity." In another way, that a thing must be, belongs to it by reason of something extrinsic, which is either the end or the agent. On the part of the end, as when without it the end is not to be attained or so well attained: for instance, food is said to be necessary for life, and a horse is necessary for a journey. This is called "necessity of end," and sometimes also "utility." On the part of the agent, a thing must be, when someone is forced by some agent, so that he is not able to do the contrary. This is called "necessity of coercion."

Now this necessity of coercion is altogether repugnant to the will. For we call that violent which is against the inclination of a thing. But the very movement of the will is an inclination to something. Therefore, as a thing is called natural because it is according to the inclination of nature, so a thing is called voluntary because it is according to the inclination of the will. Therefore, just as it is impossible for a thing to be at the same time violent and natural, so it is impossible for a thing to be absolutely coerced or violent, and voluntary.

But necessity of end is not repugnant to the will, when the end cannot be attained except in one way: thus from the will to cross the sea, arises in the will the necessity to wish for a ship.

In like manner neither is natural necessity repugnant to the will. Indeed, more than this, for as the intellect of necessity adheres to the first principles, the will must of necessity adhere to the last end, which is happiness: since the end is in practical matters what the principle is in speculative matters. For what befits a thing naturally and immovably must be the root and principle of all else appertaining thereto, since the nature of a thing is the first in everything, and every movement arises from something immovable.

Reply to Objection: 1. The words of Augustine are to be understood of the necessity of coercion. But natural necessity "does not take away the liberty of the will," as he says himself (De Civ. Dei v, 10).

2. The will, so far as it desires a thing naturally, corresponds rather to the intellect as regards natural principles than to the reason, which extends to opposite things. Wherefore in this respect it is rather an intellectual than a rational power.

3. We are masters of our own actions by reason of our being able to choose this or that. But choice regards not the end, but "the means to the end," as the Philosopher says (Ethic. iii, 9). Wherefore the desire of the ultimate end does not regard those actions of which we are masters.



Article: 2 Whether the will desires of necessity, whatever it desires?




Objection: 1. It would seem that the will desires all things of necessity, whatever it desires. For Dionysius says (Div. Nom. iv) that "evil is outside the scope of the will." Therefore the will tends of necessity to the good which is proposed to it.

2. Further, the object of the will is compared to the will as the mover to the thing movable. But the movement of the movable necessarily follows the mover. Therefore it seems that the will's object moves it of necessity.

3. Further, as the thing apprehended by sense is the object of the sensitive appetite, so the thing apprehended by the intellect is the object of the intellectual appetite, which is called the will. But what is apprehended by the sense moves the sensitive appetite of necessity: for Augustine says (Gn ad lit. ix, 14) that "animals are moved by things seen." Therefore it seems that whatever is apprehended by the intellect moves the will of necessity.

On the contrary Augustine says (Retract. i, 9) that "it is the will by which we sin and live well," and so the will extends to opposite things. Therefore it does not desire of necessity all things whatsoever it desires.

I answer that The will does not desire of necessity whatsoever it desires. In order to make this evident we must observe that as the intellect naturally and of necessity adheres to the first principles, so the will adheres to the last end, as we have said already (Article [1]). Now there are some things intelligible which have not a necessary connection with the first principles; such as contingent propositions, the denial of which does not involve a denial of the first principles. And to such the intellect does not assent of necessity. But there are some propositions which have a necessary connection with the first principles: such as demonstrable conclusions, a denial of which involves a denial of the first principles. And to these the intellect assents of necessity, when once it is aware of the necessary connection of these conclusions with the principles; but it does not assent of necessity until through the demonstration it recognizes the necessity of such connection. It is the same with the will. For there are certain individual goods which have not a necessary connection with happiness, because without them a man can be happy: and to such the will does not adhere of necessity. But there are some things which have a necessary connection with happiness, by means of which things man adheres to God, in Whom alone true happiness consists. Nevertheless, until through the certitude of the Divine Vision the necessity of such connection be shown, the will does not adhere to God of necessity, nor to those things which are of God. But the will of the man who sees God in His essence of necessity adheres to God, just as now we desire of necessity to be happy. It is therefore clear that the will does not desire of necessity whatever it desires.

Reply to Objection: 1. The will can tend to nothing except under the aspect of good. But because good is of many kinds, for this reason the will is not of necessity determined to one.

2. The mover, then, of necessity causes movement in the thing movable, when the power of the mover exceeds the thing movable, so that its entire capacity is subject to the mover. But as the capacity of the will regards the universal and perfect good, its capacity is not subjected to any individual good. And therefore it is not of necessity moved by it.

3. The sensitive power does not compare different things with each other, as reason does: but it simply apprehends some one thing. Therefore, according to that one thing, it moves the sensitive appetite in a determinate way. But the reason is a power that compares several things together: therefore from several things the intellectual appetite---that is, the will---may be moved; but not of necessity from one thing.




Summa Th. I EN Qu.79 a.13