Reply Obj. 1:  The sensitive appetite is related to the will, which is the rational appetite, through being moved by it.  And therefore the act of the appetitive power is consummated in the sensitive appetite:  and for this reason the sensitive appetite is the subject of virtue.  Whereas the sensitive powers of apprehension are related to the intellect rather through moving it; for the reason that the phantasms are related to the intellective soul, as colors to sight (De Anima iii, text. 18).  And therefore the act of knowledge is terminated in the intellect; and for this reason the cognoscitive virtues are in the intellect itself, or the reason.

And thus is made clear the Reply to the Second Objection.

Reply Obj. 3:  Memory is not a part of prudence, as species is of a genus, as though memory were a virtue properly so called:  but one of the conditions required for prudence is a good memory; so that, in a fashion, it is after the manner of an integral part. ________________________

SIXTH ARTICLE [I-II, Q. 56, Art. 6]

Whether the Will Can Be the Subject of Virtue?

Objection 1:  It would seem that the will is not the subject of virtue.  Because no habit is required for that which belongs to a power by reason of its very nature.  But since the will is in the reason, it is of the very essence of the will, according to the Philosopher (De Anima iii, text. 42), to tend to that which is good, according to reason.  And to this good every virtue is ordered, since everything naturally desires its own proper good; for virtue, as Tully says in his Rhetoric, is a “habit like a second nature in accord with reason.”  Therefore the will is not the subject of virtue.

Obj. 2:  Further, every virtue is either intellectual or moral (Ethic. i, 13; ii, 1).  But intellectual virtue is subjected in the intellect and reason, and not in the will:  while moral virtue is subjected in the irascible and concupiscible powers which are rational by participation.  Therefore no virtue is subjected in the will.

Obj. 3:  Further, all human acts, to which virtues are ordained, are voluntary.  If therefore there be a virtue in the will in respect of some human acts, in like manner there will be a virtue in the will in respect of all human acts.  Either, therefore, there will be no virtue in any other power, or there will be two virtues ordained to the same act, which seems unreasonable.  Therefore the will cannot be the subject of virtue.

On the contrary, Greater perfection is required in the mover than in the moved.  But the will moves the irascible and concupiscible powers.  Much more therefore should there be virtue in the will than in the irascible and concupiscible powers.

I answer that, Since the habit perfects the power in reference to act, then does the power need a habit perfecting it unto doing well, which habit is a virtue, when the power’s own proper nature does not suffice for the purpose.