Thomas Aquinas

“ Of the evils which man has to avoid, some are of frequent occurrence; the like can be grasped by reason, and against them caution is directed, either that they may be avoided altogether, or that they may do less harm. Others there are that occur rarely and by chance, and these, since they are infinite in number, cannot be grasped by reason, nor is man able to take precautions against them, although by exercising prudence he is able to prepare against all the surprises of chance, so as to suffer less harm thereby. ”

“ And although certain things are necessary for an end, which are subject to divine providence, yet nothing is subject to human providence except the contingent matters of actions which can be done by man for an end. ”

“ Now every deduction of reason proceeds from certain statements which are taken as primary: wherefore every process of reasoning must needs proceed from some understanding. Therefore since prudence is right reason applied to action, the whole process of prudence must needs have its source in understanding. Hence it is that understanding is reckoned a part of prudence. ”

“ Hence in matters of prudence man stands in very great need of being taught by others, especially by old folk who have acquired a sane understanding of the ends in practical matters. Wherefore the Philosopher says (Ethic. vi, 11) : "It is right to pay no less attention to the undemonstrated assertions and opinions of such persons as are experienced, older than we are, and prudent, than to their demonstrations, for their experience gives them an insight into principles." ”

“ Consequently, future contingents, in so far as they can be directed by man to the end of human life, are the matter of prudence: and each of these things is implied in the word foresight, for it implies the notion of something distant, to which that which occurs in the present has to be directed. ”

“ It is the same in idea, to ensue good and to avoid the opposite evil, but the avoidance of outward hindrances is different in idea. Hence caution differs from foresight, although they both belong to the one virtue of prudence. ”

“ I answer that, Prudence consists in a right estimate about matters of action. Now a right estimate or opinion is acquired in two ways, both in practical and in speculative matters, first by discovering it oneself, secondly by learning it from others. Now just as docility consists in a man being well disposed to acquire a right opinion from another man, so shrewdness is an apt disposition to acquire a right estimate by oneself, yet so that shrewdness be taken for {eustochia}, of which it is a part. ”

“ Further, whoever can see things afar off can much more see things that are near. Now foresight enables a man to look on distant things. Therefore there is no need to account circumspection a part of prudence in addition to foresight. ”

“ The Philosopher adduces the true reason (Ethic. vi, 9) to prove that {euboulia}, i.e. good counsel, is not {eustochia}, which is commended for grasping quickly what should be done. Now a man may take good counsel, though he be long and slow in so doing, and yet this does not discount the utility of a happy conjecture in taking good counsel: indeed it is sometimes a necessity, when, for instance, something has to be done without warning. It is for this reason that shrewdness is fittingly reckoned a part of prudence. ”

“ Thus matters of art, though they are singular, are nevertheless more fixed and certain, wherefore in many of them there is no room for counsel on account of their certitude, as stated in Ethic. iii, 3. Hence, although in certain other intellectual virtues reason is more certain than in prudence, yet prudence above all requires that man be an apt reasoner, so that he may rightly apply universals to particulars, which latter are various and uncertain. ”

“ Now the past has become a kind of necessity, since what has been done cannot be undone. In like manner, the present as such, has a kind of necessity, since it is necessary that Socrates sit, so long as he sits. ”

“ Now the reason for the necessity of finding these illustrations or images, is that simple and spiritual impressions easily slip from the mind, unless they be tied as it were to some corporeal image, because human knowledge has a greater hold on sensible objects. For this reason memory is assigned to the sensitive part of the soul. ”