Whether Prudence Is a Virtue Necessary to Man?

Objection 1:  It would seem that prudence is not a virtue necessary to lead a good life.  For as art is to things that are made, of which it is the right reason, so is prudence to things that are done, in respect of which we judge of a man’s life:  for prudence is the right reason about these things, as stated in Ethic. vi, 5.  Now art is not necessary in things that are made, save in order that they be made, but not after they have been made.  Neither, therefore is prudence necessary to man in order to lead a good life, after he has become virtuous; but perhaps only in order that he may become virtuous.

Obj. 2:  Further, “It is by prudence that we are of good counsel,” as stated in Ethic. vi, 5.  But man can act not only from his own, but also from another’s good counsel.  Therefore man does not need prudence in order to lead a good life, but it is enough that he follow the counsels of prudent men.

Obj. 3:  Further, an intellectual virtue is one by which one always tells the truth, and never a falsehood.  But this does not seem to be the case with prudence:  for it is not human never to err in taking counsel about what is to be done; since human actions are about things that may be otherwise than they are.  Hence it is written (Wis. 9:14):  “The thoughts of mortal men are fearful, and our counsels uncertain.”  Therefore it seems that prudence should not be reckoned an intellectual virtue.

On the contrary, It is reckoned with other virtues necessary for human life, when it is written (Wis. 8:7) of Divine Wisdom:  “She teacheth temperance and prudence and justice and fortitude, which are such things as men can have nothing more profitable in life.”

I answer that, Prudence is a virtue most necessary for human life.  For a good life consists in good deeds.  Now in order to do good deeds, it matters not only what a man does, but also how he does it; to wit, that he do it from right choice and not merely from impulse or passion.  And, since choice is about things in reference to the end, rectitude of choice requires two things:  namely, the due end, and something suitably ordained to that due end.  Now man is suitably directed to his due end by a virtue which perfects the soul in the appetitive part, the object of which is the good and the end.  And to that which is suitably ordained to the due end man needs to be rightly disposed by a habit in his reason, because counsel and choice, which are about things ordained to the end, are acts of the reason.  Consequently an intellectual virtue is needed in the reason, to perfect the reason, and make it suitably affected towards things ordained to the end; and this virtue is prudence.  Consequently prudence is a virtue necessary to lead a good life.