Obj. 2:  Further, it belongs to the higher to judge the lower.  The highest virtue would therefore seem to be the one whose act is judgment.  Now synesis enables us to judge well.  Therefore synesis is not a virtue annexed to prudence, but rather is a principal virtue.

Obj. 3:  Further, just as there are various matters to pass judgment on, so are there different points on which one has to take counsel.  But there is one virtue referring to all matters of counsel.  Therefore, in order to judge well of what has to be done, there is no need, besides synesis, of the virtue of gnome.

Obj. 4:  Further, Cicero (De Invent.  Rhet. iii) mentions three other parts of prudence; viz. “memory of the past, understanding of the present, and foresight of the future.”  Moreover, Macrobius (Super Somn.  Scip. 1) mentions yet others:  viz. “caution, docility,” and the like.  Therefore it seems that the above are not the only virtues annexed to prudence.

On the contrary, stands the authority of the Philosopher (Ethic. vi, 9, 10, 11), who assigns these three virtues as being annexed to prudence.

I answer that, Wherever several powers are subordinate to one another, that power is the highest which is ordained to the highest act.  Now there are three acts of reason in respect of anything done by man:  the first of these is counsel; the second, judgment; the third, command.  The first two correspond to those acts of the speculative intellect, which are inquiry and judgment, for counsel is a kind of inquiry:  but the third is proper to the practical intellect, in so far as this is ordained to operation; for reason does not have to command in things that man cannot do.  Now it is evident that in things done by man, the chief act is that of command, to which all the rest are subordinate.  Consequently, that virtue which perfects the command, viz. prudence, as obtaining the highest place, has other secondary virtues annexed to it, viz. eustochia, which perfects counsel; and synesis and gnome, which are parts of prudence in relation to judgment, and of whose distinction we shall speak further on (ad 3).

Reply Obj. 1:  Prudence makes us be of good counsel, not as though its immediate act consisted in being of good counsel, but because it perfects the latter act by means of a subordinate virtue, viz. euboulia.

Reply Obj. 2:  Judgment about what is to be done is directed to something further:  for it may happen in some matter of action that a man’s judgment is sound, while his execution is wrong.  The matter does not attain to its final complement until the reason has commanded aright in the point of what has to be done.