Objection 1. It would seem that there can be prudence in sinners. For our Lord said (Luke 16:8): "The children of this world are more prudent [Douay: 'wiser'] in their generation than the children of light." Now the children of this world are sinners. Therefore there be prudence in sinners.
Objection 2. Further, faith is a more excellent virtue than prudence. But there can be faith in sinners. Therefore there can be prudence also.
Objection 3. Further, according to Ethic. vi, 7, "we say that to be of good counsel is the work of prudent man especially." Now many sinners can take good counsel. Therefore sinners can have prudence.
On the contrary, The Philosopher declares (Ethic. vi, 12) that "it is impossible for a man be prudent unless he be good." Now no inner is a good man. Therefore no sinner is prudent.
I answer that, Prudence is threefold. There is a false prudence, which takes its name from its likeness to true prudence. For since a prudent man is one who disposes well of the things that have to be done for a good end, whoever disposes well of such things as are fitting for an evil end, has false prudence, in far as that which he takes for an end, is good, not in truth but in appearance. Thus man is called "a good robber," and in this way may speak of "a prudent robber," by way of similarity, because he devises fitting ways of committing robbery. This is the prudence of which the Apostle says (Romans 8:6): "The prudence [Douay: 'wisdom'] of the flesh is death," because, to wit, it places its ultimate end in the pleasures of the flesh.
The second prudence is indeed true prudence, because it devises fitting ways of obtaining a good end; and yet it is imperfect, from a twofold source. First, because the good which it takes for an end, is not the common end of all human life, but of some particular affair; thus when a man devises fitting ways of conducting business or of sailing a ship, he is called a prudent businessman, or a prudent sailor; secondly, because he fails in the chief act of prudence, as when a man takes counsel aright, and forms a good judgment, even about things concerning life as a whole, but fails to make an effective command.
The third prudence is both true and perfect, for it takes counsel, judges and commands aright in respect of the good end of man's whole life: and this alone is prudence simply so-called, and cannot be in sinners, whereas the first prudence is in sinners alone, while imperfect prudence is common to good and wicked men, especially that which is imperfect through being directed to a particular end, since that which is imperfect on account of a failing in the chief act, is only in the wicked.
Reply to Objection 1. This saying of our Lord is to be understood of the first prudence, wherefore it is not said that they are prudent absolutely, but that they are prudent in "their generation."
Reply to Objection 2. The nature of faith consists not in conformity with the appetite for certain right actions, but in knowledge alone. On the other hand prudence implies a relation to a right appetite. First because its principles are the ends in matters of action; and of such ends one forms a right estimate through the habits of moral virtue, which rectify the appetite: wherefore without the moral virtues there is no prudence, as shown above (I-II, 58, 5); secondly because prudence commands right actions, which does not happen unless the appetite be right. Wherefore though faith on account of its object is more excellent than prudence, yet prudence, by its very nature, is more opposed to sin, which arises from a disorder of the appetite.
Reply to Objection 3. Sinners can take good counsel for an evil end, or for some particular good, but they do not perfectly take good counsel for the end of their whole life, since they do not carry that counsel into effect. Hence they lack prudence which is directed to the good only; and yet in them, according to the Philosopher (Ethic. vi, 12) there is "cleverness," [deinotike] i.e. natural diligence which may be directed to both good and evil; or "cunning," [panourgia] which is directed only to evil, and which we have stated above, to be "false prudence" or "prudence of the flesh."
Source: Summa Theologica (New Advent)