Summa Th. II-II EN Qu.45 a.2

Whether wisdom is in the intellect as its subject?

Objection: 1. It would seem that wisdom is not in the intellect as its subject. For Augustine says (Ep. cxx) that "wisdom is the charity of God." Now charity is in the will as its subject, and not in the intellect, as stated above (Question [24], Article [1]). Therefore wisdom is not in the intellect as its subject.
2. Further, it is written (Si 6,23): "The wisdom of doctrine is according to her name," for wisdom [sapientia] may be described as "sweet-tasting science [sapida scientia]," and this would seem to regard the appetite, to which it belongs to taste spiritual pleasure or sweetness. Therefore wisdom is in the appetite rather than in the intellect.
3. Further, the intellective power is sufficiently perfected by the gift of understanding. Now it is superfluous to require two things where one suffices for the purpose. Therefore wisdom is not in the intellect.

On the contrary Gregory says (Moral. ii, 49) that "wisdom is contrary to folly." But folly is in the intellect. Therefore wisdom is also.
I answer that As stated above (Article [1]), wisdom denotes a certain rectitude of judgment according to the Eternal Law. Now rectitude of judgment is twofold: first, on account of perfect use of reason, secondly, on account of a certain connaturality with the matter about which one has to judge. Thus, about matters of chastity, a man after inquiring with his reason forms a right judgment, if he has learnt the science of morals, while he who has the habit of chastity judges of such matters by a kind of connaturality.Accordingly it belongs to the wisdom that is an intellectual virtue to pronounce right judgment about Divine things after reason has made its inquiry, but it belongs to wisdom as a gift of the Holy Ghost to judge aright about them on account of connaturality with them: thus Dionysius says (Div. Nom. ii) that "Hierotheus is perfect in Divine things, for he not only learns, but is patient of, Divine things."Now this sympathy or connaturality for Divine things is the result of charity, which unites us to God, according to 1Co 6,17: "He who is joined to the Lord, is one spirit." Consequently wisdom which is a gift, has its cause in the will, which cause is charity, but it has its essence in the intellect, whose act is to judge aright, as stated above (FS, Question [14], Article [1]).

Reply to Objection: 1. Augustine is speaking of wisdom as to its cause, whence also wisdom [sapientia] takes its name, in so far as it denotes a certain sweetness [saporem].
2. Hence the Reply to the Second Objection is evident, that is if this be the true meaning of the text quoted. For, apparently this is not the case, because such an exposition of the text would only fit the Latin word for wisdom, whereas it does not apply to the Greek and perhaps not in other languages. Hence it would seem that in the text quoted wisdom stands for the renown of doctrine, for which it is praised by all.
3. The intellect exercises a twofold act, perception and judgment. The gift of understanding regards the former; the gift of wisdom regards the latter according to the Divine ideas, the gift of knowledge, according to human ideas.

Whether wisdom is merely speculative, or practical also?

Objection: 1. It would seem that wisdom is not practical but merely speculative. For the gift of wisdom is more excellent than the wisdom which is an intellectual virtue. But wisdom, as an intellectual virtue, is merely speculative. Much more therefore is wisdom, as a gift, speculative and not practical.
2. Further, the practical intellect is about matters of operation which are contingent. But wisdom is about Divine things which are eternal and necessary. Therefore wisdom cannot be practical.
3. Further, Gregory says (Moral. vi, 37) that "in contemplation we seek the Beginning which is God, but in action we labor under a mighty bundle of wants." Now wisdom regards the vision of Divine things, in which there is no toiling under a load, since according to Sg 8,16, "her conversation hath no bitterness, nor her company any tediousness." Therefore wisdom is merely contemplative, and not practical or active.

On the contrary It is written (Col 4,5): "Walk with wisdom towards them that are without." Now this pertains to action. Therefore wisdom is not merely speculative, but also practical.
I answer that As Augustine says (De Trin. xii, 14), the higher part of the reason is the province of wisdom, while the lower part is the domain of knowledge. Now the higher reason according to the same authority (De Trin. xii, 7) "is intent on the consideration and consultation of the heavenly," i.e. Divine, "types" [*Cf. FP, Question [79], Article [9]; FS, Question [74], Article [7]]; it considers them, in so far as it contemplates Divine things in themselves, and it consults them, in so far as it judges of human acts by Divine things, and directs human acts according to Divine rules.Accordingly wisdom as a gift, is not merely speculative but also practical.

Reply to Objection: 1. The higher a virtue is, the greater the number of things to which it extends, as stated in De Causis, prop. x, xvii. Wherefore from the very fact that wisdom as a gift is more excellent than wisdom as an intellectual virtue, since it attains to God more intimately by a kind of union of the soul with Him, it is able to direct us not only in contemplation but also in action.
2. Divine things are indeed necessary and eternal in themselves, yet they are the rules of the contingent things which are the subject-matter of human actions.
3. A thing is considered in itself before being compared with something else. Wherefore to wisdom belongs first of all contemplation which is the vision of the Beginning, and afterwards the direction of human acts according to the Divine rules. Nor from the direction of wisdom does there result any bitterness or toil in human acts; on the contrary the result of wisdom is to make the bitter sweet, and labor a rest.

Whether wisdom can be without grace, and with mortal sin?

Objection: 1. It would seem that wisdom can be without grace and with mortal sin. For saints glory chiefly in such things as are incompatible with mortal sin, according to 2Co 1,12: "Our glory is this, the testimony of our conscience." Now one ought not to glory in one's wisdom, according to Jr 9,23: "Let not the wise man glory in his wisdom." Therefore wisdom can be without grace and with mortal sin.
2. Further, wisdom denotes knowledge of Divine things, as stated above (Article [1]). Now one in mortal sin may have knowledge of the Divine truth, according to Rm 1,18: "(Those men that) detain the truth of God in injustice." Therefore wisdom is compatible with mortal sin.
3. Further, Augustine says (De Trin. xv, 18) while speaking of charity: "Nothing surpasses this gift of God, it is this alone that divides the children of the eternal kingdom from the children of eternal perdition." But wisdom is distinct from charity. Therefore it does not divide the children of the kingdom from the children of perdition. Therefore it is compatible with mortal sin.

On the contrary It is written (Sg 1,4): "Wisdom will not enter into a malicious soul, nor dwell in a body subject to sins."
I answer that The wisdom which is a gift of the Holy Ghost, as stated above (Article [1]), enables us to judge aright of Divine things, or of other things according to Divine rules, by reason of a certain connaturalness or union with Divine things, which is the effect of charity, as stated above (Article [2]; Question [23], Article [5]). Hence the wisdom of which we are speaking presupposes charity. Now charity is incompatible with mortal sin, as shown above (Question [24], Article [12]). Therefore it follows that the wisdom of which we are speaking cannot be together with mortal sin.

Reply to Objection: 1. These words are to be understood as referring to worldly wisdom, or to wisdom in Divine things acquired through human reasons. In such wisdom the saints do not glory, according to Pr 30,2: "The wisdom of men is not with Me": But they do glory in Divine wisdom according to 1Co 1,30: "(Who) of God is made unto us wisdom."
2. This argument considers, not the wisdom of which we speak but that which is acquired by the study and research of reason, and is compatible with mortal sin.
3. Although wisdom is distinct from charity, it presupposes it, and for that very reason divides the children of perdition from the children of the kingdom.

Whether wisdom is in all who have grace?

Objection: 1. It would seem that wisdom is not in all who have grace. For it is more to have wisdom than to hear wisdom. Now it is only for the perfect to hear wisdom, according to 1Co 2,6: "We speak wisdom among the perfect." Since then not all who have grace are perfect, it seems that much less all who have grace have wisdom.
2. Further, "The wise man sets things in order," as the Philosopher states (Metaph. i, 2): and it is written (Jc 3,17) that the wise man "judges without dissimulation [*Vulg.: 'The wisdom that is from above . . . is . . . without judging, without dissimulation']". Now it is not for all that have grace, to judge, or put others in order, but only for those in authority. Therefore wisdom is not in all that have grace.
3. Further, "Wisdom is a remedy against folly," as Gregory says (Moral. ii, 49). Now many that have grace are naturally foolish, for instance madmen who are baptized or those who without being guilty of mortal sin have become insane. Therefore wisdom is not in all that have grace.

On the contrary Whoever is without mortal sin, is beloved of God; since he has charity, whereby he loves God, and God loves them that love Him (Pr 8,17). Now it is written (Sg 7,28) that "God loveth none but him that dwelleth with wisdom." Therefore wisdom is in all those who have charity and are without mortal sin.
I answer that The wisdom of which we are speaking, as stated above (Article [4]), denotes a certain rectitude of judgment in the contemplation and consultation of Divine things, and as to both of these men obtain various degrees of wisdom through union with Divine things. For the measure of right judgment attained by some, whether in the contemplation of Divine things or in directing human affairs according to Divine rules, is no more than suffices for their salvation. This measure is wanting to none who is without mortal sin through having sanctifying grace, since if nature does not fail in necessaries, much less does grace fail: wherefore it is written (1Jn 2,27): "(His) unction teacheth you of all things."Some, however, receive a higher degree of the gift of wisdom, both as to the contemplation of Divine things (by both knowing more exalted mysteries and being able to impart this knowledge to others) and as to the direction of human affairs according to Divine rules (by being able to direct not only themselves but also others according to those rules). This degree of wisdom is not common to all that have sanctifying grace, but belongs rather to the gratuitous graces, which the Holy Ghost dispenses as He will, according to 1Co 12,8: "To one indeed by the Spirit is given the word of wisdom," etc.

Reply to Objection: 1. The Apostle speaks there of wisdom, as extending to the hidden mysteries of Divine things, as indeed he says himself (2Co 1,7): "We speak the wisdom of God in a mystery, a wisdom which is hidden."
2. Although it belongs to those alone who are in authority to direct and judge other men, yet every man is competent to direct and judge his own actions, as Dionysius declares (Ep ad Demophil.).
3. Baptized idiots, like little children, have the habit of wisdom, which is a gift of the Holy Ghost, but they have not the act, on account of the bodily impediment which hinders the use of reason in them.

Whether the seventh beatitude corresponds to the gift of wisdom?

Objection: 1. It seems that the seventh beatitude does not correspond to the gift of wisdom. For the seventh beatitude is: "Blessed are the peacemakers, for they shall be called the children of God." Now both these things belong to charity: since of peace it is written (Ps 118,165): "Much peace have they that love Thy law," and, as the Apostle says (Rm 5,5), "the charity of God is poured forth in our hearts by the Holy Ghost Who is given to us," and Who is "the Spirit of adoption of sons, whereby we cry: Abba [Father]" (Rm 8,15). Therefore the seventh beatitude ought to be ascribed to charity rather than to wisdom.
2. Further, a thing is declared by its proximate effect rather than by its remote effect. Now the proximate effect of wisdom seems to be charity, according to Sg 7,27: "Through nations she conveyeth herself into holy souls; she maketh the friends of God and prophets": whereas peace and the adoption of sons seem to be remote effects, since they result from charity, as stated above (Question [29], Article [3]). Therefore the beatitude corresponding to wisdom should be determined in respect of the love of charity rather than in respect of peace.
3. Further, it is written (Jc 3,17): "The wisdom, that is from above, first indeed is chaste, then peaceable, modest, easy to be persuaded, consenting to the good, full of mercy and good fruits, judging without dissimulation [*Vulg.: 'without judging, without dissimulation']." Therefore the beatitude corresponding to wisdom should not refer to peace rather than to the other effects of heavenly wisdom.

On the contrary Augustine says (De Serm. Dom. in Monte i, 4) that "wisdom is becoming to peacemakers, in whom there is no movement of rebellion, but only obedience to reason."
I answer that The seventh beatitude is fittingly ascribed to the gift of wisdom, both as to the merit and as to the reward. The merit is denoted in the words, "Blessed are the peacemakers." Now a peacemaker is one who makes peace, either in himself, or in others: and in both cases this is the result of setting in due order those things in which peace is established, for "peace is the tranquillity of order," according to Augustine (De Civ. Dei xix, 13). Now it belongs to wisdom to set things in order, as the Philosopher declares (Metaph. i, 2), wherefore peaceableness is fittingly ascribed to wisdom. The reward is expressed in the words, "they shall be called the children of God." Now men are called the children of God in so far as they participate in the likeness of the only-begotten and natural Son of God, according to Rm 8,29, "Whom He foreknew . . . to be made conformable to the image of His Son," Who is Wisdom Begotten. Hence by participating in the gift of wisdom, man attains to the sonship of God.

Reply to Objection: 1. It belongs to charity to be at peace, but it belongs to wisdom to make peace by setting things in order. Likewise the Holy Ghost is called the "Spirit of adoption" in so far as we receive from Him the likeness of the natural Son, Who is the Begotten Wisdom.
2. These words refer to the Uncreated Wisdom, which in the first place unites itself to us by the gift of charity, and consequently reveals to us the mysteries the knowledge of which is infused wisdom. Hence, the infused wisdom which is a gift, is not the cause but the effect of charity.
3. As stated above (Article [3]) it belongs to wisdom, as a gift, not only to contemplate Divine things, but also to regulate human acts. Now the first thing, to be effected in this direction of human acts is the removal of evils opposed to wisdom: wherefore fear is said to be "the beginning of wisdom," because it makes us shun evil, while the last thing is like an end, whereby all things are reduced to their right order; and it is this that constitutes peace. Hence James said with reason that "the wisdom that is from above" (and this is the gift of the Holy Ghost) "first indeed is chaste," because it avoids the corruption of sin, and "then peaceable," wherein lies the ultimate effect of wisdom, for which reason peace is numbered among the beatitudes. As to the things that follow, they declare in becoming order the means whereby wisdom leads to peace. For when a man, by chastity, avoids the corruption of sin, the first thing he has to do is, as far as he can, to be moderate in all things, and in this respect wisdom is said to be modest. Secondly, in those matters in which he is not sufficient by himself, he should be guided by the advice of others, and as to this we are told further that wisdom is "easy to be persuaded." These two are conditions required that man may be at peace with himself. But in order that man may be at peace with others it is furthermore required, first that he should not be opposed to their good; this is what is meant by "consenting to the good." Secondly, that he should bring to his neighbor's deficiencies, sympathy in his heart, and succor in his actions, and this is denoted by the words "full of mercy and good fruits." Thirdly, he should strive in all charity to correct the sins of others, and this is indicated by the words "judging without dissimulation [*Vulg.: 'The wisdom that is from above . . . is . . . without judging, without dissimulation']," lest he should purpose to sate his hatred under cover of correction.


We must now consider folly which is opposed to wisdom; and under this head there are three points of inquiry:

(1) Whether folly is contrary to wisdom?

(2) Whether folly is a sin?

(3) To which capital sin is it reducible?

Whether folly is contrary to wisdom?

Objection: 1. It would seem that folly is not contrary to wisdom. For seemingly unwisdom is directly opposed to wisdom. But folly does not seem to be the same as unwisdom, for the latter is apparently about Divine things alone, whereas folly is about both Divine and human things. Therefore folly is not contrary to wisdom.
2. Further, one contrary is not the way to arrive at the other. But folly is the way to arrive at wisdom, for it is written (1Co 3,18): "If any man among you seem to be wise in this world, let him become a fool, that he may be wise." Therefore folly is not opposed to wisdom.
3. Further, one contrary is not the cause of the other. But wisdom is the cause of folly; for it is written (Jr 10,14): "Every man is become a fool for knowledge," and wisdom is a kind of knowledge. Moreover, it is written (Is 47,10): "Thy wisdom and thy knowledge, this hath deceived thee." Now it belongs to folly to be deceived. Therefore folly is not contrary to wisdom.
4. Further, Isidore says (Etym. x, under the letter S) that "a fool is one whom shame does not incite to sorrow, and who is unconcerned when he is injured." But this pertains to spiritual wisdom, according to Gregory (Moral. x, 49). Therefore folly is not opposed to wisdom.

On the contrary Gregory says (Moral. ii, 26) that "the gift of wisdom is given as a remedy against folly."
I answer that Stultitia [Folly] seems to take its name from "stupor"; wherefore Isidore says (Etym. x, under the letter of S): "A fool is one who through dullness [stuporem] remains unmoved." And folly differs from fatuity, according to the same authority (Etym. x), in that folly implies apathy in the heart and dullness in the senses, while fatuity denotes entire privation of the spiritual sense. Therefore folly is fittingly opposed to wisdom.For "sapiens" [wise] as Isidore says (Etym. x) "is so named from sapor [savor], because just as the taste is quick to distinguish between savors of meats, so is a wise man in discerning things and causes." Wherefore it is manifest that "folly" is opposed to "wisdom" as its contrary, while "fatuity" is opposed to it as a pure negation: since the fatuous man lacks the sense of judgment, while the fool has the sense, though dulled, whereas the wise man has the sense acute and penetrating.

Reply to Objection: 1. According to Isidore (Etym. x), "unwisdom is contrary to wisdom because it lacks the savor of discretion and sense"; so that unwisdom is seemingly the same as folly. Yet a man would appear to be a fool chiefly through some deficiency in the verdict of that judgment, which is according to the highest cause, for if a man fails in judgment about some trivial matter, he is not for that reason called a fool.
2. Just as there is an evil wisdom, as stated above (Question [45], Article [1], ad 1), called "worldly wisdom," because it takes for the highest cause and last end some worldly good, so too there is a good folly opposed to this evil wisdom, whereby man despises worldly things: and it is of this folly that the Apostle speaks.
3. It is the wisdom of the world that deceives and makes us foolish in God's sight, as is evident from the Apostle's words (1Co 3,19).
4. To be unconcerned when one is injured is sometimes due to the fact that one has no taste for worldly things, but only for heavenly things. Hence this belongs not to worldly but to Divine wisdom, as Gregory declares (Moral. x, 49). Sometimes however it is the result of a man's being simply stupid about everything, as may be seen in idiots, who do not discern what is injurious to them, and this belongs to folly simply.

Whether folly is a sin?

Objection: 1. It would seem that folly is not a sin. For no sin arises in us from nature. But some are fools naturally. Therefore folly is not a sin.
2. Further, "Every sin is voluntary," according to Augustine (De Vera Relig. xiv). But folly is not voluntary. Therefore it is not a sin.
3. Further, every sin is contrary to a Divine precept. But folly is not contrary to any precept. Therefore folly is not a sin.

On the contrary It is written (Pr 1,32): "The prosperity of fools shall destroy them." But no man is destroyed save for sin. Therefore folly is a sin.
I answer that Folly, as stated above (Article [1]), denotes dullness of sense in judging, and chiefly as regards the highest cause, which is the last end and the sovereign good. Now a man may in this respect contract dullness in judgment in two ways. First, from a natural indisposition, as in the case of idiots, and such like folly is no sin. Secondly, by plunging his sense into earthly things, whereby his sense is rendered incapable of perceiving Divine things, according to 1Co 2,14, "The sensual man perceiveth not these things that are of the Spirit of God," even as sweet things have no savor for a man whose taste is infected with an evil humor: and such like folly is a sin.

Reply to Objection: 1. This suffices for the Reply to the First Objection.
2. Though no man wishes to be a fool, yet he wishes those things of which folly is a consequence, viz. to withdraw his sense from spiritual things and to plunge it into earthly things. The same thing happens in regard to other sins; for the lustful man desires pleasure, without which there is no sin, although he does not desire sin simply, for he would wish to enjoy the pleasure without sin.
3. Folly is opposed to the precepts about the contemplation of truth, of which we have spoken above (Question [16]) when we were treating of knowledge and understanding.

Whether folly is a daughter of lust?

Objection: 1. It would seem that folly is not a daughter of lust. For Gregory (Moral. xxxi, 45) enumerates the daughters of lust, among which however he makes no mention of folly. Therefore folly does not proceed from lust.
2. Further, the Apostle says (1Co 3,19): "The wisdom of this world is foolishness with God." Now, according to Gregory (Moral. x, 29) "the wisdom of this world consists in covering the heart with crafty devices;" and this savors of duplicity. Therefore folly is a daughter of duplicity rather than of lust.
3. Further, anger especially is the cause of fury and madness in some persons; and this pertains to folly. Therefore folly arises from anger rather than from lust.

On the contrary It is written (Pr 7,22): "Immediately he followeth her," i.e. the harlot . . . "not knowing that he is drawn like a fool to bonds."
I answer that As already stated (Article [2]), folly, in so far as it is a sin, is caused by the spiritual sense being dulled, so as to be incapable of judging spiritual things. Now man's sense is plunged into earthly things chiefly by lust, which is about the greatest of pleasures; and these absorb the mind more than any others. Therefore the folly which is a sin, arises chiefly from lust.

Reply to Objection: 1. It is part of folly that a man should have a distaste for God and His gifts. Hence Gregory mentions two daughters of lust, pertaining to folly, namely, "hatred of God" and "despair of the life to come"; thus he divides folly into two parts as it were.
2. These words of the Apostle are to be understood, not causally but essentially, because, to wit, worldly wisdom itself is folly with God. Hence it does not follow that whatever belongs to worldly wisdom, is a cause of this folly.
3. Anger by reason of its keenness, as stated above (FS, Question [48], Articles [2],3,4), produces a great change in the nature of the body, wherefore it conduces very much to the folly which results from a bodily impediment. On the other hand the folly which is caused by a spiritual impediment, viz. by the mind being plunged into earthly things, arises chiefly from lust, as stated above.


ON PRUDENCE (Questions [47]-56)


After treating of the theological virtues, we must in due sequence consider the cardinal virtues. In the first place we shall consider prudence in itself; secondly, its parts; thirdly, the corresponding gift; fourthly, the contrary vices; fifthly, the precepts concerning prudence.

Under the first head there are sixteen points of inquiry:

(1) Whether prudence is in the will or in the reason?

(2) If in the reason, whether it is only in the practical, or also in the speculative reason?

(3) Whether it takes cognizance of singulars?

(4) Whether it is virtue?

(5) Whether it is a special virtue?

(6) Whether it appoints the end to the moral virtues?

(7) Whether it fixes the mean in the moral virtues?

(8) Whether its proper act is command?

(9) Whether solicitude or watchfulness belongs to prudence?

(10) Whether prudence extends to the governing of many?

(11) Whether the prudence which regards private good is the same in species as that which regards the common good?

(12) Whether prudence is in subjects, or only in their rulers?

(13) Whether prudence is in the wicked?

(14) Whether prudence is in all good men?

(15) Whether prudence is in us naturally?

(16) Whether prudence is lost by forgetfulness ?

Whether prudence is in the cognitive or in the appetitive faculty?

Objection: 1. It would seem that prudence is not in the cognitive but in the appetitive faculty. For Augustine says (De Morib. Eccl. xv): "Prudence is love choosing wisely between the things that help and those that hinder." Now love is not in the cognitive, but in the appetitive faculty. Therefore prudence is in the appetitive faculty.
2. Further, as appears from the foregoing definition it belongs to prudence "to choose wisely." But choice is an act of the appetitive faculty, as stated above (FS, Question [13], Article [1]). Therefore prudence is not in the cognitive but in the appetitive faculty.
3. Further, the Philosopher says (Ethic. vi, 5) that "in art it is better to err voluntarily than involuntarily, whereas in the case of prudence, as of the virtues, it is worse." Now the moral virtues, of which he is treating there, are in the appetitive faculty, whereas art is in the reason. Therefore prudence is in the appetitive rather than in the rational faculty.

On the contrary Augustine says (Questions. lxxxiii, qu. 61): "Prudence is the knowledge of what to seek and what to avoid."
I answer that As Isidore says (Etym. x): "A prudent man is one who sees as it were from afar, for his sight is keen, and he foresees the event of uncertainties." Now sight belongs not to the appetitive but to the cognitive faculty. 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.

Reply to Objection: 1. As stated above (FP, Question [82], Article [4]) the will moves all the faculties to their acts. Now the first act of the appetitive faculty is love, as stated above (FS, Question [25], Articles [1],2). 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.
2. The prudent man considers things afar off, in so far as they tend to be a help or a hindrance to that which has to be done at the present time. Hence it is clear that those things which prudence considers stand in relation to this other, as in relation to the end. Now of those things that are directed to the end there is counsel in the reason, and choice in the appetite, of which two, counsel belongs more properly to prudence, since the Philosopher states (Ethic. vi, 5,7,9) that a prudent man "takes good counsel." But as choice presupposes counsel, since it is "the desire for what has been already counselled" (Ethic. iii, 2), it follows that choice can also be ascribed to prudence indirectly, in so far, to wit, as prudence directs the choice by means of counsel.
3. The worth of prudence consists not in thought merely, but in its application to action, which is the end of the practical reason. Wherefore if any defect occur in this, it is most contrary to prudence, since, the end being of most import in everything, it follows that a defect which touches the end is the worst of all. Hence the Philosopher goes on to say (Ethic. vi, 5) that prudence is "something more than a merely rational habit," such as art is, since, as stated above (FS, Question [57], Article [4]) it includes application to action, which application is an act of the will.

Whether prudence belongs to the practical reason alone or also to the speculative reason?

Objection: 1. It would seem that prudence belongs not only to the practical, but also to the speculative reason. For it is written (Pr 10,23): "Wisdom is prudence to a man." Now wisdom consists chiefly in contemplation. Therefore prudence does also.
2. Further, Ambrose says (De Offic. i, 24): "Prudence is concerned with the quest of truth, and fills us with the desire of fuller knowledge." Now this belongs to the speculative reason. Therefore prudence resides also in the speculative reason.
3. Further, the Philosopher assigns art and prudence to the same part of the soul (Ethic. vi, 1). Now art may be not only practical but also speculative, as in the case of the liberal arts. Therefore prudence also is both practical and speculative.

On the contrary The Philosopher says (Ethic. vi, 5) that prudence is right reason applied to action. Now this belongs to none but the practical reason. Therefore prudence is in the practical reason only.
I answer that According to the Philosopher (Ethic. vi, 5) "a prudent man is one who is capable of taking good counsel." Now counsel is about things that we have to do in relation to some end: and the reason that deals with things to be done for an end is the practical reason. Hence it is evident that prudence resides only in the practical reason.

Reply to Objection: 1. As stated above (Question [45], Articles [1],3), wisdom considers the absolutely highest cause: so that the consideration of the highest cause in any particular genus belongs to wisdom in that genus. Now in the genus of human acts the highest cause is the common end of all human life, and it is this end that prudence intends. For the Philosopher says (Ethic. vi, 5) that just as he who reasons well for the realization of a particular end, such as victory, is said to be prudent, not absolutely, but in a particular genus, namely warfare, so he that reasons well with regard to right conduct as a whole, is said to be prudent absolutely. Wherefore it is clear that prudence is wisdom about human affairs: but not wisdom absolutely, because it is not about the absolutely highest cause, for it is about human good, and this is not the best thing of all. And so it is stated significantly that "prudence is wisdom for man," but not wisdom absolutely.
2. Ambrose, and Tully also (De Invent. ii, 53) take the word prudence in a broad sense for any human knowledge, whether speculative or practical. And yet it may also be replied that the act itself of the speculative reason, in so far as it is voluntary, is a matter of choice and counsel as to its exercise; and consequently comes under the direction of prudence. On the other hand, as regards its specification in relation to its object which is the "necessary true," it comes under neither counsel nor prudence.
3. 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.

Summa Th. II-II EN Qu.45 a.2