Reply Obj. 1:  The good of an art is to be found, not in the craftsman, but in the product of the art, since art is right reason about things to be made:  for since the making of a thing passes into external matter, it is a perfection not of the maker, but of the thing made, even as movement is the act of the thing moved:  and art is concerned with the making of things.  On the other hand, the good of prudence is in the active principle, whose activity is its perfection:  for prudence is right reason about things to be done, as stated above (A. 4).  Consequently art does not require of the craftsman that his act be a good act, but that his work be good.  Rather would it be necessary for the thing made to act well (e.g. that a knife should carve well, or that a saw should cut well), if it were proper to such things to act, rather than to be acted on, because they have not dominion over their actions.  Wherefore the craftsman needs art, not that he may live well, but that he may produce a good work of art, and have it in good keeping:  whereas prudence is necessary to man, that he may lead a good life, and not merely that he may be a good man.

Reply Obj. 2:  When a man does a good deed, not of his own counsel, but moved by that of another, his deed is not yet quite perfect, as regards his reason in directing him and his appetite in moving him.  Wherefore, if he do a good deed, he does not do well simply; and yet this is required in order that he may lead a good life.

Reply Obj. 3:  As stated in Ethic. vi, 2, truth is not the same for the practical as for the speculative intellect.  Because the truth of the speculative intellect depends on conformity between the intellect and the thing.  And since the intellect cannot be infallibly in conformity with things in contingent matters, but only in necessary matters, therefore no speculative habit about contingent things is an intellectual virtue, but only such as is about necessary things.  On the other hand, the truth of the practical intellect depends on conformity with right appetite.  This conformity has no place in necessary matters, which are not affected by the human will; but only in contingent matters which can be effected by us, whether they be matters of interior action, or the products of external work.  Hence it is only about contingent matters that an intellectual virtue is assigned to the practical intellect, viz. art, as regards things to be made, and prudence, as regards things to be done. ________________________

SIXTH ARTICLE [I-II, Q. 57, Art. 6]

Whether “Eubulia,” “Synesis,” and “Gnome” Are Virtues Annexed to
Prudence?

Objection 1:  It would seem that “eubulia, synesis, and gnome” are unfittingly assigned as virtues annexed to prudence.  For eubulia is “a habit whereby we take good counsel” (Ethic. vi, 9).  Now it “belongs to prudence to take good counsel,” as stated (Ethic. vi, 9).  Therefore eubulia is not a virtue annexed to prudence, but rather is prudence itself.