Now the act of understanding is not said to be common to soul and body, except in respect of the phantasm, as is stated in De Anima, text. 66. But it is clear that the phantasm is compared as object to the passive intellect (De Anima iii, text. 3, 39). Whence it follows that the intellective habit is chiefly on the part of the intellect itself; and not on the part of the phantasm, which is common to soul and body. And therefore we must say that the "possible" intellect is the subject of habit, which is in potentiality to many: and this belongs, above all, to the "possible" intellect. Wherefore the "possible" intellect is the subject of intellectual habits.
Reply Obj. 2: As potentiality to sensible being belongs to corporeal matter, so potentiality to intellectual being belongs to the "possible" intellect. Wherefore nothing forbids habit to be in the "possible" intellect, for it is midway between pure potentiality and perfect act.
Reply Obj. 3: Because the apprehensive powers inwardly prepare their proper objects for the possible intellect, therefore it is by the good disposition of these powers, to which the good disposition of the body cooperates, that man is rendered apt to understand. And so in a secondary way the intellective habit can be in these powers. But principally it is in the "possible" intellect. ________________________
FIFTH ARTICLE [I-II, Q. 50, Art. 5]
Whether Any Habit Is in the Will?
Objection 1: It would seem that there is not a habit in the will. For the habit which is in the intellect is the intelligible species, by means of which the intellect actually understands. But the will does not act by means of species. Therefore the will is not the subject of habit.
Obj. 2: Further, no habit is allotted to the active intellect, as there is to the "possible" intellect, because the former is an active power. But the will is above all an active power, because it moves all the powers to their acts, as stated above (Q. 9, A. 1). Therefore there is no habit in the will.
Obj. 3: Further, in the natural powers there is no habit, because, by reason of their nature, they are determinate to one thing. But the will, by reason of its nature, is ordained to tend to the good which reason directs. Therefore there is no habit in the will.
On the contrary, Justice is a habit. But justice is in the will; for it is "a habit whereby men will and do that which is just" (Ethic. v, 1). Therefore the will is the subject of a habit.
I answer that, Every power which may be variously directed to act, needs a habit whereby it is well disposed to its act. Now since the will is a rational power, it may be variously directed to act. And therefore in the will we must admit the presence of a habit whereby it is well disposed to its act. Moreover, from the very nature of habit, it is clear that it is principally related to the will; inasmuch as habit "is that which one uses when one wills," as stated above (A. 1).