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 (Question 9, Article 3). 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 (15, 3, 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.
Source: Summa Theologica (New Advent)