For it is clear that there are some virtues in the irascible and concupiscible powers.  Because an act, which proceeds from one power according as it is moved by another power, cannot be perfect, unless both powers be well disposed to the act:  for instance, the act of a craftsman cannot be successful unless both the craftsman and his instrument be well disposed to act.  Therefore in the matter of the operations of the irascible and concupiscible powers, according as they are moved by reason, there must needs be some habit perfecting in respect of acting well, not only the reason, but also the irascible and concupiscible powers.  And since the good disposition of the power which moves through being moved, depends on its conformity with the power that moves it:  therefore the virtue which is in the irascible and concupiscible powers is nothing else but a certain habitual conformity of these powers to reason.

Reply Obj. 1:  The irascible and concupiscible powers considered in themselves, as parts of the sensitive appetite, are common to us and dumb animals.  But in so far as they are rational by participation, and are obedient to the reason, they are proper to man.  And in this way they can be the subject of human virtue.

Reply Obj. 2:  Just as human flesh has not of itself the good of virtue, but is made the instrument of a virtuous act, inasmuch as being moved by reason, we “yield our members to serve justice”; so also, the irascible and concupiscible powers, of themselves indeed, have not the good of virtue, but rather the infection of the fomes: whereas, inasmuch as they are in conformity with reason, the good of reason is begotten in them.

Reply Obj. 3:  The body is ruled by the soul, and the irascible and concupiscible powers by the reason, but in different ways.  For the body obeys the soul blindly without any contradiction, in those things in which it has a natural aptitude to be moved by the soul:  whence the Philosopher says (Polit. i, 3) that the “soul rules the body with a despotic command” as the master rules his slave:  wherefore the entire movement of the body is referred to the soul.  For this reason virtue is not in the body, but in the soul.  But the irascible and concupiscible powers do not obey the reason blindly; on the contrary, they have their own proper movements, by which, at times, they go against reason, whence the Philosopher says (Polit. i, 3) that the “reason rules the irascible and concupiscible powers by a political command” such as that by which free men are ruled, who have in some respects a will of their own.  And for this reason also must there be some virtues in the irascible and concupiscible powers, by which these powers are well disposed to act.

Reply Obj. 4:  In choice there are two things, namely, the intention of the end, and this belongs to the moral virtue; and the preferential choice of that which is unto the end, and this belongs to prudence (Ethic. vi, 2, 5).  But that the irascible and concupiscible powers have a right intention of the end in regard to the passions of the soul, is due to the good disposition of these powers.  And therefore those moral virtues which are concerned with the passions are in the irascible and concupiscible powers, but prudence is in the reason. ________________________