Summa Theologica, by St. Thomas Aquinas, , at sacred-texts.com
We must now consider use; concerning which there are four points of inquiry:
(1) Whether use is an act of the will?
(2) Whether it is to be found in irrational animals?
(3) Whether it regards the means only, or the end also?
(4) Of the relation of use to choice.
Objection 1: It would seem that use is not an act of the will. For Augustine says (De Doctr. Christ. i, 4) that "to use is to refer that which is the object of use to the obtaining of something else." But "to refer" something to another is an act of the reason to which it belongs to compare and to direct. Therefore use is an act of the reason and not of the will.
Objection 2: Further, Damascene says (De Fide Orth. ii, 22) that man "goes forward to the operation, and this is called impulse; then he makes use (of the powers) and this is called use." But operation belongs to the executive power; and the act of the will does not follow the act of the executive power, on the contrary execution comes last. Therefore use is not an act of the will.
Objection 3: Further, Augustine says (QQ. 83, qu. 30): "All things that were made were made for man's use, because reason with which man is endowed uses all things by its judgment of them." But judgment of things created by God belongs to the speculative reason; which seems to be altogether distinct from the will, which is the principle of human acts. Therefore use is not an act of the will.
On the contrary, Augustine says (De Trin. x, 11): "To use is to apply to something to purpose of the will."
I answer that, The use of a thing implies the application of that thing to an operation: hence the operation to which we apply a thing is called its use; thus the use of a horse is to ride, and the use of a stick is to strike. Now we apply to an operation not only the interior principles of action, viz. the powers of the soul or the members of the body; as the intellect, to understand; and the eye, to see; but also external things, as a stick, to strike. But it is evident that we do not apply external things to an operation save through the interior principles which are either the powers of the soul, or the habits of those powers, or the organs which are parts of the body. Now it has been shown above (Q, A) that it is the will which moves the soul's powers to their acts, and this is to apply them to operation. Hence it is evident that first and principally use belongs to the will as first mover; to the reason, as directing; and to the other powers as executing the operation, which powers are compared to the will which applies them to act, as the instruments are compared to the principal agent. Now action is properly ascribed, not to the instrument, but to the principal agent, as building is ascribed to the builder, not to his tools. Hence it is evident that use is, properly speaking, an act of the will.
Reply to Objection 1: Reason does indeed refer one thing to another; but the will tends to that which is referred by the reason to something else. And in this sense to use is to refer one thing to another.
Reply to Objection 2: Damascene is speaking of use in so far as it belongs to the executive powers.
Reply to Objection 3: Even the speculative reason is applied by the will to the act of understanding or judging. Consequently the speculative reason is said to use, in so far as it is moved by the will, in the same way as the other powers.
Objection 1: It would seem that use is to be found in irrational animals. For it is better to enjoy than to use, because, as Augustine says (De Trin. x, 10): "We use things by referring them to something else which we are to enjoy." But enjoyment is to be found in irrational animals, as stated above (Q, A). Much more, therefore, is it possible for them to use.
Objection 2: Further, to apply the members to action is to use them. But irrational animals apply their members to action; for instance, their feet, to walk; their horns, to strike. Therefore it is possible for irrational animals to use.
On the contrary, Augustine says (QQ. 83, qu. 30): "None but a rational animal can make use of a thing."
I answer that, as stated above (A), to use is to apply an active principle to action: thus to consent is to apply the appetitive movement to the desire of something, as stated above (Q, AA,2,3). Now he alone who has the disposal of a thing, can apply it to something else; and this belongs to him alone who knows how to refer it to something else, which is an act of the reason. And therefore none but a rational animal consents and uses.
Reply to Objection 1: To enjoy implies the absolute movement of the appetite to the appetible: whereas to use implies a movement of the appetite to something as directed to something else. If therefore we compare use and enjoyment in respect of their objects, enjoyment is better than use; because that which is appetible absolutely is better than that which is appetible only as directed to something else. But if we compare them in respect of the apprehensive power that precedes them, greater excellence is required on the part of use: because to direct one thing to another is an act of reason; whereas to apprehend something absolutely is within the competency even of sense.
Reply to Objection 2: Animals by means of their members do something from natural instinct; not through knowing the relation of their members to these operations. Wherefore, properly speaking, they do not apply their members to action, nor do they use them.
Objection 1: It would seem that use can regard also the last end. For Augustine says (De Trin. x, 11): "Whoever enjoys, uses." But man enjoys the last end. Therefore he uses the last end.
Objection 2: Further, "to use is to apply something to the purpose of the will" (De Trin. x, 11). But the last end, more than anything else, is the object of the will's application. Therefore it can be the object of use.
Objection 3: Further, Hilary says (De Trin. ii) that "Eternity is in the Father, Likeness in the Image," i.e. in the Son, "Use in the Gift," i.e. in the Holy Ghost. But the Holy Ghost, since He is God, is the last end. Therefore the last end can be the object of use.
On the contrary, Augustine says (QQ. 83, qu. 30): "No one rightly uses God, but one enjoys Him." But God alone is the last end. Therefore we cannot use the last end.
I answer that, Use, as stated above (A), implies the application of one thing to another. Now that which is applied to another is regarded in the light of means to an end; and consequently use always regards the means. For this reason things that are adapted to a certain end are said to be "useful"; in fact their very usefulness is sometimes called use.
It must, however, be observed that the last end may be taken in two ways: first, simply; secondly, in respect of an individual. For since the end, as stated above (Q, A; Q, A), signifies sometimes the thing itself, and sometimes the attainment or possession of that thing (thus the miser's end is either money or the possession of it); it is evident that, simply speaking, the last end is the thing itself; for the possession of money is good only inasmuch as there is some good in money. But in regard to the individual, the obtaining of money is the last end; for the miser would not seek for money, save that he might have it. Therefore, simply and properly speaking, a man enjoys money, because he places his last end therein; but in so far as he seeks to possess it, he is said to use it.
Reply to Objection 1: Augustine is speaking of use in general, in so far as it implies the relation of an end to the enjoyment which a man seeks in that end.
Reply to Objection 2: The end is applied to the purpose of the will, that the will may find rest in it. Consequently this rest in the end, which is the enjoyment thereof, is in this sense called use of the end. But the means are applied to the will's purpose, not only in being used as means, but as ordained to something else in which the will finds rest.
Reply to Objection 3: The words of Hilary refer to use as applicable to rest in the last end; just as, speaking in a general sense, one may be said to use the end for the purpose of attaining it, as stated above. Hence Augustine says (De Trin. vi, 10) that "this love, delight, felicity, or happiness, is called use by him."
Objection 1: It would seem that use precedes choice. For nothing follows after choice, except execution. But use, since it belongs to the will, precedes execution. Therefore it precedes choice also.
Objection 2: Further, the absolute precedes the relative. Therefore the less relative precedes the more relative. But choice implies two relations: one, of the thing chosen, in relation to the end; the other, of the thing chosen, in respect of that to which it is preferred; whereas use implies relation to the end only. Therefore use precedes choice.
Objection 3: Further, the will uses the other powers in so far as it removes them. But the will moves itself, too, as stated above (Q, A). Therefore it uses itself, by applying itself to act. But it does this when it consents. Therefore there is use in consent. But consent precedes choice as stated above (Q, A, ad 3). Therefore use does also.
On the contrary, Damascene says (De Fide Orth. ii, 22) that "the will after choosing has an impulse to the operation, and afterwards it uses (the powers)." Therefore use follows choice.
I answer that, The will has a twofold relation to the thing willed. One, according as the thing willed is, in a way, in the willing subject, by a kind of proportion or order to the thing willed. Wherefore those things that are naturally proportionate to a certain end, are said to desire that end naturally. Yet to have an end thus is to have it imperfectly. Now every imperfect thing tends to perfection. And therefore both the natural and the voluntary appetite tend to have the end in reality; and this is to have it perfectly. This is the second relation of the will to the thing willed.
Now the thing willed is not only the end, but also the means. And the last act that belongs to the first relation of the will to the means, is choice; for there the will becomes fully proportionate, by willing the means fully. Use, on the other hand, belongs to the second relation of the will, in respect of which it tends to the realization of the thing willed. Wherefore it is evident that use follows choice; provided that by use we mean the will's use of the executive power in moving it. But since the will, in a way, moves the reason also, and uses it, we may take the use of the means, as consisting in the consideration of the reason, whereby it refers the means to the end. In this sense use precedes choice.
Reply to Objection 1: The motion of the will to the execution of the work, precedes execution, but follows choice. And so, since use belongs to that very motion of the will, it stands between choice and execution.
Reply to Objection 2: What is essentially relative is after the absolute; but the thing to which relation is referred need not come after. Indeed, the more a cause precedes, the more numerous the effects to which it has relation.
Reply to Objection 3: Choice precedes use, if they be referred to the same object. But nothing hinders the use of one thing preceding the choice of another. And since the acts of the will react on one another, in each act of the will we can find both consent and choice and use; so that we may say that the will consents to choose, and consents to consent, and uses itself in consenting and choosing. And such acts as are ordained to that which precedes, precede also.