Prudence - Article 12

Article 12. Whether prudence is in subjects, or only in their rulers?

The Philosopher says (Ethic. vi, 8) that there are two kinds of political prudence, one of which is "legislative" and belongs to rulers, while the other "retains the common name political," and is about "individual actions." Now it belongs also to subjects to perform these individual actions. Therefore prudence is not only in rulers but also in subjects.

I answer that, Prudence is in the reason. Now ruling and governing belong properly to the reason; and therefore it is proper to a man to reason and be prudent in so far as he has a share in ruling and governing. But it is evident that the subject as subject, and the slave as slave, are not competent to rule and govern, but rather to be ruled and governed. Therefore prudence is not the virtue of a slave as slave, nor of a subject as subject. Since, however, every man, for as much as he is rational, has a share in ruling according to the judgment of reason, he is proportionately competent to have prudence. Wherefore it is manifest that prudence is in the ruler "after the manner of a mastercraft" (Ethic. vi, 8), but in the subjects, "after the manner of a handicraft."

http://www.newadvent.org/summa/3047.htm#article12