Thomas Aquinas

“ I answer that, The proper end of each moral virtue consists precisely in conformity with right reason. For temperance intends that man should not stray from reason for the sake of his concupiscences; fortitude, that he should not stray from the right judgment of reason through fear or daring. Moreover this end is appointed to man according to natural reason, since natural reason dictates to each one that he should act according to reason.
But it belongs to the ruling of prudence to decide in what manner and by what means man shall obtain the mean of reason in his deeds. ”

“ Every application of right reason in the work of production belongs to art: but to prudence belongs only the application of right reason in matters of counsel, which are those wherein there is no fixed way of obtaining the end, as stated in Ethic. iii, 3. Since then, the speculative reason makes things such as syllogisms, propositions and the like, wherein the process follows certain and fixed rules, consequently in respect of such things it is possible to have the essentials of art, but not of prudence; and so we find such a thing as a speculative art, but not a speculative prudence. ”

“ Hence if any habits rectify the consideration of reason, without regarding the rectitude of the appetite, they have less of the nature of a virtue since they direct man to good materially, that is to say, to the thing which is good, but without considering it under the aspect of good. ”

“ The end concerns the moral virtues, not as though they appointed the end, but because they tend to the end which is appointed by natural reason. In this they are helped by prudence, which prepares the way for them, by disposing the means. Hence it follows that prudence is more excellent than the moral virtues, and moves them: yet "synderesis" moves prudence, just as the understanding of principles moves science. ”

“ 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. ”

“ Accordingly prudence is said to be love, not indeed essentially, but in so far as love moves to the act of prudence. Wherefore Augustine goes on to say that "prudence is love discerning aright that which helps from that which hinders us in tending to God." Now love is said to discern because it moves the reason to discern. ”

“ Augustine there takes science in the broad sense for any kind of right reason.
Reply to Objection 2: The Philosopher says that there is a virtue of art, because art does not require rectitude of the appetite; wherefore in order that a man may make right use of his art, he needs to have a virtue which will rectify his appetite. Prudence however has nothing to do with the matter of art, because art is both directed to a particular end, and has fixed means of obtaining that end. And yet, by a kind of comparison, a man may be said to act prudently in matters of art. ”

“ Further, a habit is not diversified in species or essence by things which are subordinate to one another. But the particular good, which belongs to prudence simply so called, is subordinate to the common good, which belongs to political prudence. Therefore prudence and political prudence differ neither specifically nor essentially. ”

“ It would seem that prudence is not a special virtue. For no special virtue is included in the definition of virtue in general, since virtue is defined (Ethic. ii, 6) "an elective habit that follows a mean appointed by reason in relation to ourselves, even as a wise man decides." Now right reason is reason in accordance with prudence, as stated in Ethic. ”

“ Yet many young people have grace. Therefore prudence is not to be found in all who have grace.
On the contrary, No man has grace unless he be virtuous. Now no man can be virtuous without prudence, for Gregory says (Moral. ii, 46) that "the other virtues cannot be virtues at all unless they effect prudently what they desire to accomplish." Therefore all who have grace have prudence. ”

“ Wherefore it is manifest that prudence belongs directly to the cognitive, and not to the sensitive faculty, because by the latter we know nothing but what is within reach and offers itself to the senses: while to obtain knowledge of the future from knowledge of the present or past, which pertains to prudence, belongs properly to the reason, because this is done by a process of comparison. It follows therefore that prudence, properly speaking, is in the reason. ”

“ On the other hand prudence is differentiated from the moral virtues according to a formal aspect distinctive of powers, i.e. the intellective power, wherein is prudence, and the appetitive power, wherein is moral virtue. Hence it is evident that prudence is a special virtue, distinct from all other virtues. ”

“ Wherefore, in children who have been baptized but have not come to the use of reason, there is prudence as to habit but not as to act, even as in idiots; whereas in those who have come to the use of reason, it is also as to act, with regard to things necessary for salvation. ”

“ This argument proves that prudence helps all the virtues, and works in all of them; but this does not suffice to prove that it is not a special virtue; for nothing prevents a certain genus from containing a species which is operative in every other species of that same genus, even as the sun has an influence over all bodies. ”

“ On the other hand, as regards the knowledge of particulars which are the matter of action, we must make a further distinction, because this matter of action is either an end or the means to an end. Now the right ends of human life are fixed ”

“ There is also another diligence which is more than sufficient, whereby a man is able to make provision both for himself and for others, not only in matters necessary for salvation, but also in all things relating to human life ”

“ Reply to Objection 2: As the Philosopher declares (Polit. iii, 2) , "it belongs to a good man to be able to rule well and to obey well," wherefore the virtue of a good man includes also that of a good ruler. ”