Reply Obj. 3:  Reason is shown to be so much the more perfect, according as it is able to overcome or endure more easily the weakness of the body and of the lower powers.  And therefore human virtue, which is attributed to reason, is said to be “made perfect in infirmity,” not of the reason indeed, but of the body and of the lower powers. ________________________

FOURTH ARTICLE [I-II, Q. 55, Art. 4]

Whether Virtue Is Suitably Defined?

Objection 1:  It would seem that the definition, usually given, of virtue, is not suitable, to wit:  “Virtue is a good quality of the mind, by which we live righteously, of which no one can make bad use, which God works in us, without us.”  For virtue is man’s goodness, since virtue it is that makes its subject good.  But goodness does not seem to be good, as neither is whiteness white.  It is therefore unsuitable to describe virtue as a “good quality.”

Obj. 2:  Further, no difference is more common than its genus; since it is that which divides the genus.  But good is more common than quality, since it is convertible with being.  Therefore “good” should not be put in the definition of virtue, as a difference of quality.

Obj. 3:  Further, as Augustine says (De Trin. xii, 3):  “When we come across anything that is not common to us and the beasts of the field, it is something appertaining to the mind.”  But there are virtues even of the irrational parts; as the Philosopher says (Ethic. iii, 10).  Every virtue, therefore, is not a good quality “of the mind.”

Obj. 4:  Further, righteousness seems to belong to justice; whence the righteous are called just.  But justice is a species of virtue.  It is therefore unsuitable to put “righteous” in the definition of virtue, when we say that virtue is that “by which we live righteously.”

Obj. 5:  Further, whoever is proud of a thing, makes bad use of it.  But many are proud of virtue, for Augustine says in his Rule, that “pride lies in wait for good works in order to slay them.”  It is untrue, therefore, “that no one can make bad use of virtue.”

Obj. 6:  Further, man is justified by virtue.  But Augustine commenting on John 15:11:  “He shall do greater things than these,” says [Tract. xxvii in Joan.:  Serm. xv de Verb.  Ap. 11]:  “He who created thee without thee, will not justify thee without thee.”  It is therefore unsuitable to say that “God works virtue in us, without us.”

On the contrary, We have the authority of Augustine from whose words this definition is gathered, and principally in De Libero Arbitrio ii, 19.

I answer that, This definition comprises perfectly the whole essential notion of virtue.  For the perfect essential notion of anything is gathered from all its causes.  Now the above definition comprises all the causes of virtue.  For the formal cause of virtue, as of everything, is gathered from its genus and difference, when it is defined as “a good quality”:  for “quality” is the genus of virtue, and the difference, “good.”  But the definition would be more suitable if for “quality” we substitute “habit,” which is the proximate genus.