Summa Th. II-II EN Qu.53
We must now consider the vices opposed to prudence. For Augustine says (Contra Julian. iv, 3): "There are vices opposed to every virtue, not only vices that are in manifest opposition to virtue, as temerity is opposed to prudence, but also vices which have a kind of kinship and not a true but a spurious likeness to virtue; thus in opposition to prudence we have craftiness."
Accordingly we must consider first of all those vices which are in evident opposition to prudence, those namely which are due to a defect either of prudence or of those things which are requisite for prudence, and secondly those vices which have a false resemblance to prudence, those namely which are due to abuse of the things required for prudence. And since solicitude pertains to prudence, the first of these considerations will be twofold: (1) Of imprudence; (2) Of negligence which is opposed to solicitude.
Under the first head there are six points of inquiry:
(1) Concerning imprudence, whether it is a sin?
(2) Whether it is a special sin?
(3) Of precipitation or temerity;
(4) Of thoughtlessness;
(5) Of inconstancy;
(6) Concerning the origin of these vices.
Objection: 1. It would seem that imprudence is not a sin. For every sin is voluntary, according to Augustine [*De Vera Relig. xiv]; whereas imprudence is not voluntary, since no man wishes to be imprudent. Therefore imprudence is not a sin.
2. Further, none but original sin comes to man with his birth. But imprudence comes to man with his birth, wherefore the young are imprudent; and yet it is not original sin which is opposed to original justice. Therefore imprudence is not a sin.
3. Further, every sin is taken away by repentance. But imprudence is not taken away by repentance. Therefore imprudence is not a sin.
On the contrary The spiritual treasure of grace is not taken away save by sin. But it is taken away by imprudence, according to Pr 21,20, "There is a treasure to be desired, and oil in the dwelling of the just, and the imprudent [Douay: 'foolish'] man shall spend it." Therefore imprudence is a sin.
I answer that Imprudence may be taken in two ways, first, as a privation, secondly, as a contrary. Properly speaking it is not taken as a negation, so as merely to signify the absence of prudence, for this can be without any sin. Taken as a privation, imprudence denotes lack of that prudence which a man can and ought to have, and in this sense imprudence is a sin by reason of a man's negligence in striving to have prudence.Imprudence is taken as a contrary, in so far as the movement or act of reason is in opposition to prudence: for instance, whereas the right reason of prudence acts by taking counsel, the imprudent man despises counsel, and the same applies to the other conditions which require consideration in the act of prudence. In this way imprudence is a sin in respect of prudence considered under its proper aspect, since it is not possible for a man to act against prudence, except by infringing the rules on which the right reason of prudence depends. Wherefore, if this should happen through aversion from the Divine Law, it will be a mortal sin, as when a man acts precipitately through contempt and rejection of the Divine teaching: whereas if he act beside the Law and without contempt, and without detriment to things necessary for salvation, it will be a venial sin.
Reply to Objection: 1. No man desires the deformity of imprudence, but the rash man wills the act of imprudence, because he wishes to act precipitately. Hence the Philosopher says (Ethic. vi, 5) that "he who sins willingly against prudence is less to be commended."
2. This argument takes imprudence in the negative sense. It must be observed however that lack of prudence or of any other virtue is included in the lack of original justice which perfected the entire soul. Accordingly all such lack of virtue may be ascribed to original sin.
3. Repentance restores infused prudence, and thus the lack of this prudence ceases; but acquired prudence is not restored as to the habit, although the contrary act is taken away, wherein properly speaking the sin of imprudence consists.
Objection: 1. It would seem that imprudence is not a special sin. For whoever sins, acts against right reason, i.e. against prudence. But imprudence consists in acting against prudence, as stated above (Article ). Therefore imprudence is not a special sin.
2. Further, prudence is more akin to moral action than knowledge is. But ignorance which is opposed to knowledge, is reckoned one of the general causes of sin. Much more therefore should imprudence be reckoned among those causes.
3. Further, sin consists in the corruption of the circumstances of virtue, wherefore Dionysius says (Div. Nom. iv) that "evil results from each single defect." Now many things are requisite for prudence; for instance, reason, intelligence docility, and so on, as stated above (Questions ,49). Therefore there are many species of imprudence, so that it is not a special sin.
On the contrary Imprudence is opposed to prudence, as stated above (Article ). Now prudence is a special virtue. Therefore imprudence too is one special vice.
I answer that A vice or sin may be styled general in two ways; first, absolutely, because, to wit, it is general in respect of all sins; secondly, because it is general in respect of certain vices, which are its species. In the first way, a vice may be said to be general on two counts: first, essentially, because it is predicated of all sins: and in this way imprudence is not a general sin, as neither is prudence a general virtue: since it is concerned with special acts, namely the very acts of reason: secondly, by participation; and in this way imprudence is a general sin: for, just as all the virtues have a share of prudence, in so far as it directs them, so have all vices and sins a share of imprudence, because no sin can occur, without some defect in an act of the directing reason, which defect belongs to imprudence.If, on the other hand, a sin be called general, not simply but in some particular genus, that is, as containing several species of sin, then imprudence is a general sin. For it contains various species in three ways. First, by opposition to the various subjective parts of prudence, for just as we distinguish the prudence that guides the individual, from other kinds that govern communities, as stated above (Question ; Question , Article ), so also we distinguish various kinds of imprudence. Secondly, in respect of the quasi-potential parts of prudence, which are virtues connected with it, and correspond to the several acts of reason. Thus, by defect of "counsel" to which (euboulia) (deliberating well) corresponds, "precipitation" or "temerity" is a species of imprudence; by defect of "judgment," to which (synesis) (judging well according to common law) and (gnome) (judging well according to general law) refer, there is "thoughtlessness"; while "inconstancy" and "negligence" correspond to the "command" which is the proper act of prudence. Thirdly, this may be taken by opposition to those things which are requisite for prudence, which are the quasi-integral parts of prudence. Since however all these things are intended for the direction of the aforesaid three acts of reason, it follows that all the opposite defects are reducible to the four parts mentioned above. Thus incautiousness and incircumspection are included in "thoughtlessness"; lack of docility, memory, or reason is referable to "precipitation"; improvidence, lack of intelligence and of shrewdness, belong to "negligence" and "inconstancy."
Reply to Objection: 1. This argument considers generality by participation.
2. Since knowledge is further removed from morality than prudence is, according to their respective proper natures, it follows that ignorance has the nature of mortal sin, not of itself, but on account either of a preceding negligence, or of the consequent result, and for this reason it is reckoned one of the general causes of sin. On the other hand imprudence, by its very nature, denotes a moral vice; and for this reason it can be called a special sin.
3. When various circumstances are corrupted for the same motive, the species of sin is not multiplied: thus it is the same species of sin to take what is not one's own, where one ought not, and when one ought not. If, however, there be various motives, there are various species: for instance, if one man were to take another's property from where he ought not, so as to wrong a sacred place, this would constitute the species called sacrilege, while if another were to take another's property when he ought not, merely through the lust of possession, this would be a case of simple avarice. Hence the lack of those things which are requisite for prudence, does not constitute a diversity of species, except in so far as they are directed to different acts of reason, as stated above.
Objection: 1. It would seem that precipitation is not a sin included in imprudence. Imprudence is opposed to the virtue of prudence; whereas precipitation is opposed to the gift of counsel, according to Gregory, who says (Moral. ii, 49) that the gift of "counsel is given as a remedy to precipitation." Therefore precipitation is not a sin contained under imprudence.
2. Further, precipitation seemingly pertains to rashness. Now rashness implies presumption, which pertains to pride. Therefore precipitation is not a vice contained under imprudence.
3. Further, precipitation seems to denote inordinate haste. Now sin happens in counselling not only through being over hasty but also through being over slow, so that the opportunity for action passes by, and through corruption of other circumstances, as stated in Ethic. vi, 9. Therefore there is no reason for reckoning precipitation as a sin contained under imprudence, rather than slowness, or something else of the kind pertaining to inordinate counsel.
On the contrary It is written (Pr 4,19): "The way of the wicked is darksome, they know not where they fall." Now the darksome ways of ungodliness belong to imprudence. Therefore imprudence leads a man to fall or to be precipitate.
I answer that Precipitation is ascribed metaphorically to acts of the soul, by way of similitude to bodily movement. Now a thing is said to be precipitated as regards bodily movement, when it is brought down from above by the impulse either of its own movement or of another's, and not in orderly fashion by degrees. Now the summit of the soul is the reason, and the base is reached in the action performed by the body; while the steps that intervene by which one ought to descend in orderly fashion are "memory" of the past, "intelligence" of the present, "shrewdness" in considering the future outcome, "reasoning" which compares one thing with another, "docility" in accepting the opinions of others. He that takes counsel descends by these steps in due order, whereas if a man is rushed into action by the impulse of his will or of a passion, without taking these steps, it will be a case of precipitation. Since then inordinate counsel pertains to imprudence, it is evident that the vice of precipitation is contained under imprudence.
Reply to Objection: 1. Rectitude of counsel belongs to the gift of counsel and to the virtue of prudence; albeit in different ways, as stated above (Question , Article ), and consequently precipitation is opposed to both.
2. Things are said to be done rashly when they are not directed by reason: and this may happen in two ways; first through the impulse of the will or of a passion, secondly through contempt of the directing rule; and this is what is meant by rashness properly speaking, wherefore it appears to proceed from that root of pride, which refuses to submit to another's ruling. But precipitation refers to both, so that rashness is contained under precipitation, although precipitation refers rather to the first.
3. Many things have to be considered in the research of reason; hence the Philosopher declares (Ethic. vi, 9) that "one should be slow in taking counsel." Hence precipitation is more directly opposed to rectitude of counsel than over slowness is, for the latter bears a certain likeness to right counsel.
Objection: 1. It would seem that thoughtlessness is not a special sin included in imprudence. For the Divine law does not incite us to any sin, according to Ps 18,8, "The law of the Lord is unspotted"; and yet it incites us to be thoughtless, according to Mt 10,19, "Take no thought how or what to speak." Therefore thoughtlessness is not a sin.
2. Further, whoever takes counsel must needs give thought to many things. Now precipitation is due to a defect of counsel and therefore to a defect of thought. Therefore precipitation is contained under thoughtlessness: and consequently thoughtlessness is not a special sin.
3. Further, prudence consists in acts of the practical reason, viz. "counsel," "judgment" about what has been counselled, and "command" [*Cf. Question , Article ]. Now thought precedes all these acts, since it belongs also to the speculative intellect. Therefore thoughtlessness is not a special sin contained under imprudence.
On the contrary It is written (Pr 4,25): "Let thy eyes look straight on, and let thine eye-lids go before thy steps." Now this pertains to prudence, while the contrary pertains to thoughtlessness. Therefore thoughtlessness is a special sin contained under imprudence.
I answer that Thought signifies the act of the intellect in considering the truth about. something. Now just as research belongs to the reason, so judgment belongs to the intellect. Wherefore in speculative matters a demonstrative science is said to exercise judgment, in so far as it judges the truth of the results of research by tracing those results back to the first indemonstrable principles. Hence thought pertains chiefly to judgment; and consequently the lack of right judgment belongs to the vice of thoughtlessness, in so far, to wit, as one fails to judge rightly through contempt or neglect of those things on which a right judgment depends. It is therefore evident that thoughtlessness is a sin.
Reply to Objection: 1. Our Lord did not forbid us to take thought, when we have the opportunity, about what we ought to do or say, but, in the words quoted, He encourages His disciples, so that when they had no opportunity of taking thought, either through lack of knowledge or through a sudden call, they should trust in the guidance of God alone, because "as we know not what to do, we can only turn our eyes to God," according to 2Ch 20,12: else if man, instead of doing what he can, were to be content with awaiting God's assistance, he would seem to tempt God.
2. All thought about those things of which counsel takes cognizance, is directed to the formation of a right judgment, wherefore this thought is perfected in judgment. Consequently thoughtlessness is above all opposed to the rectitude of judgment.
3. Thoughtlessness is to be taken here in relation to a determinate matter, namely, that of human action, wherein more things have to be thought about for the purpose of right judgment, than in speculative matters, because actions are about singulars.
Objection: 1. It would seem that inconstancy is not a vice contained under imprudence. For inconstancy consists seemingly in a lack of perseverance in matters of difficulty. But perseverance in difficult matters belongs to fortitude. Therefore inconstancy is opposed to fortitude rather than to prudence.
2. Further, it is written (Jc 3,16): "Where jealousy [Douay: 'envy'] and contention are, there are inconstancy and every evil work." But jealousy pertains to envy. Therefore inconstancy pertains not to imprudence but to envy.
3. Further, a man would seem to be inconstant who fails to persevere in what he has proposed to do. Now this is a mark of "incontinency" in pleasurable matters, and of "effeminacy" or "squeamishness" in unpleasant matters, according to Ethic. vii, 1. Therefore inconstancy does not pertain to imprudence.
On the contrary It belongs to prudence to prefer the greater good to the lesser. Therefore to forsake the greater good belongs to imprudence. Now this is inconstancy. Therefore inconstancy belongs to imprudence.
I answer that Inconstancy denotes withdrawal from a definite good purpose. Now the origin of this withdrawal is in the appetite, for a man does not withdraw from a previous good purpose, except on account of something being inordinately pleasing to him: nor is this withdrawal completed except through a defect of reason, which is deceived in rejecting what before it had rightly accepted. And since it can resist the impulse of the passions, if it fail to do this, it is due to its own weakness in not standing to the good purpose it has conceived; hence inconstancy, as to its completion, is due to a defect in the reason. Now just as all rectitude of the practical reason belongs in some degree to prudence, so all lack of that rectitude belongs to imprudence. Consequently inconstancy, as to its completion, belongs to imprudence. And just as precipitation is due to a defect in the act of counsel, and thoughtlessness to a defect in the act of judgment, so inconstancy arises from a defect in the act of command. For a man is stated to be inconstant because his reason fails in commanding what has been counselled and judged.
Reply to Objection: 1. The good of prudence is shared by all the moral virtues, and accordingly perseverance in good belongs to all moral virtues, chiefly, however, to fortitude, which suffers a greater impulse to the contrary.
2. Envy and anger, which are the source of contention, cause inconstancy on the part of the appetite, to which power the origin of inconstancy is due, as stated above.
3. Continency and perseverance seem to be not in the appetitive power, but in the reason. For the continent man suffers evil concupiscences, and the persevering man suffers grievous sorrows (which points to a defect in the appetitive power); but reason stands firm, in the continent man, against concupiscence, and in the persevering man, against sorrow. Hence continency and perseverance seem to be species of constancy which pertains to reason; and to this power inconstancy pertains also.
Objection: 1. It would seem that the aforesaid vices do not arise from lust. For inconstancy arises from envy, as stated above (Article , ad 2). But envy is a distinct vice from lust.
2. Further, it is written (Jc 1,8): "A double-minded man is inconstant in all his ways." Now duplicity does not seem to pertain to lust, but rather to deceitfulness, which is a daughter of covetousness, according to Gregory (Moral. xxxi, 45). Therefore the aforesaid vices do not arise from lust.
3. Further, the aforesaid vices are connected with some defect of reason. Now spiritual vices are more akin to the reason than carnal vices. Therefore the aforesaid vices arise from spiritual vices rather than from carnal vices.
On the contrary Gregory declares (Moral. xxxi, 45) that the aforesaid vices arise from lust.
I answer that As the Philosopher states (Ethic. vi, 5) "pleasure above all corrupts the estimate of prudence," and chiefly sexual pleasure which absorbs the mind, and draws it to sensible delight. Now the perfection of prudence and of every intellectual virtue consists in abstraction from sensible objects. Wherefore, since the aforesaid vices involve a defect of prudence and of the practical reason, as stated above (Articles ,5), it follows that they arise chiefly from lust.
Reply to Objection: 1. Envy and anger cause inconstancy by drawing away the reason to something else; whereas lust causes inconstancy by destroying the judgment of reason entirely. Hence the Philosopher says (Ethic. vii, 6) that "the man who is incontinent through anger listens to reason, yet not perfectly, whereas he who is incontinent through lust does not listen to it at all."
2. Duplicity also is something resulting from lust, just as inconstancy is, if by duplicity we understand fluctuation of the mind from one thing to another. Hence Terence says (Eunuch. act 1, sc. 1) that "love leads to war, and likewise to peace and truce."
3. Carnal vices destroy the judgment of reason so much the more as they lead us away from reason.
We must now consider negligence, under which head there are three points of inquiry:
(1) Whether negligence is a special sin?
(2) To which virtue is it opposed?
(3) Whether negligence is a mortal sin?
Objection: 1. It would seem that negligence is not a special sin. For negligence is opposed to diligence. But diligence is required in every virtue. Therefore negligence is not a special sin.
2. Further, that which is common to every sin is not a special sin. Now negligence is common to every sin, because he who sins neglects that which withdraws him from sin, and he who perseveres in sin neglects to be contrite for his sin. Therefore negligence is not a special sin.
3. Further, every special sin had a determinate matter. But negligence seems to have no determinate matter: since it is neither about evil or indifferent things (for no man is accused of negligence if he omit them), nor about good things, for if these be done negligently, they are no longer good. Therefore it seems that negligence is not a special vice.
On the contrary Sins committed through negligence, are distinguished from those which are committed through contempt.
I answer that Negligence denotes lack of due solicitude. Now every lack of a due act is sinful: wherefore it is evident that negligence is a sin, and that it must needs have the character of a special sin according as solicitude is the act of a special virtue. For certain sins are special through being about a special matter, as lust is about sexual matters, while some vices are special on account of their having a special kind of act which extends to all kinds of matter, and such are all vices affecting an act of reason, since every act of reason extends to any kind of moral matter. Since then solicitude is a special act of reason, as stated above (Question , Article ), it follows that negligence, which denotes lack of solicitude, is a special sin.
Reply to Objection: 1. Diligence seems to be the same as solicitude, because the more we love [diligimus] a thing the more solicitous are we about it. Hence diligence, no less than solicitude, is required for every virtue, in so far as due acts of reason are requisite for every virtue.
2. In every sin there must needs be a defect affecting an act of reason, for instance a defect in counsel or the like. Hence just as precipitation is a special sin on account of a special act of reason which is omitted, namely counsel, although it may be found in any kind of sin; so negligence is a special sin on account of the lack of a special act of reason, namely solicitude, although it is found more or less in all sins.
3. Properly speaking the matter of negligence is a good that one ought to do, not that it is a good when it is done negligently, but because on account of negligence it incurs a lack of goodness, whether a due act be entirely omitted through lack of solicitude, or some due circumstance be omitted.
Objection: 1. It would seem that negligence is not opposed to prudence. For negligence seems to be the same as idleness or laziness, which belongs to sloth, according to Gregory (Moral. xxxi, 45). Now sloth is not opposed to prudence, but to charity, as stated above (Question , Article ). Therefore negligence is not opposed to prudence.
2. Further, every sin of omission seems to be due to negligence. But sins of omission are not opposed to prudence, but to the executive moral virtues. Therefore negligence is not opposed to prudence.
3. Further, imprudence relates to some act of reason. But negligence does not imply a defect of counsel, for that is "precipitation," nor a defect of judgment, since that is "thoughtlessness," nor a defect of command, because that is "inconstancy." Therefore negligence does not pertain to imprudence.
4. Further, it is written (Qo 7,19): "He that feareth God, neglecteth nothing." But every sin is excluded by the opposite virtue. Therefore negligence is opposed to fear rather than to prudence.
On the contrary It is written (Si 20,7): "A babbler and a fool [imprudens] will regard no time." Now this is due to negligence. Therefore negligence is opposed to prudence.
I answer that Negligence is directly opposed to solicitude. Now solicitude pertains to the reason, and rectitude of solicitude to prudence. Hence, on the other hand, negligence pertains to imprudence. This appears from its very name, because, as Isidore observes (Etym. x) "a negligent man is one who fails to choose [nec eligens]": and the right choice of the means belongs to prudence. Therefore negligence pertains to imprudence.
Reply to Objection: 1. Negligence is a defect in the internal act, to which choice also belongs: whereas idleness and laziness denote slowness of execution, yet so that idleness denotes slowness in setting about the execution, while laziness denotes remissness in the execution itself. Hence it is becoming that laziness should arise from sloth, which is "an oppressive sorrow," i.e. hindering, the mind from action [*Cf. Question , Article ; I-II 35,8].
2. Omission regards the external act, for it consists in failing to perform an act which is due. Hence it is opposed to justice, and is an effect of negligence, even as the execution of a just deed is the effect of right reason.
3. Negligence regards the act of command, which solicitude also regards. Yet the negligent man fails in regard to this act otherwise than the inconstant man: for the inconstant man fails in commanding, being hindered as it were, by something, whereas the negligent man fails through lack of a prompt will.
3. The fear of God helps us to avoid all sins, because according to Pr 15,27, "by the fear of the Lord everyone declineth from evil." Hence fear makes us avoid negligence, yet not as though negligence were directly opposed to fear, but because fear incites man to acts of reason. Wherefore also it has been stated above (I-II 44,2) when we were treating of the passions, that "fear makes us take counsel."
Objection: 1. It would seem that negligence cannot be a mortal sin. For a gloss of Gregory [*Moral. ix. 34] on Jb 9,28, "I feared all my works," etc. says that "too little love of God aggravates the former," viz. negligence. But wherever there is mortal sin, the love of God is done away with altogether. Therefore negligence is not a mortal sin.
2. Further, a gloss on Si 7,34, "For thy negligences purify thyself with a few," says: "Though the offering be small it cleanses the negligences of many sins." Now this would not be, if negligence were a mortal sin. Therefore negligence is not a mortal sin.
3. Further, under the law certain sacrifices were prescribed for mortal sins, as appears from the book of Leviticus. Yet no sacrifice was prescribed for negligence. Therefore negligence is not a mortal sin.
On the contrary It is written (Pr 19,16): "He that neglecteth his own life [Vulg.: 'way'] shall die."
I answer that As stated above (Article , ad 3), negligence arises out of a certain remissness of the will, the result being a lack of solicitude on the part of the reason in commanding what it should command, or as it should command. Accordingly negligence may happen to be a mortal sin in two ways. First on the part of that which is omitted through negligence. If this be either an act or a circumstance necessary for salvation, it will be a mortal sin. Secondly on the part of the cause: for if the will be so remiss about Divine things, as to fall away altogether from the charity of God, such negligence is a mortal sin, and this is the case chiefly when negligence is due to contempt.But if negligence consists in the omission of an act or circumstance that is not necessary for salvation, it is not a mortal but a venial sin, provided the negligence arise, not from contempt, but from some lack of fervor, to which venial sin is an occasional obstacle.
Reply to Objection: 1. Man may be said to love God less in two ways. First through lack of the fervor of charity, and this causes the negligence that is a venial sin: secondly through lack of charity itself, in which sense we say that a man loves God less when he loves Him with a merely natural love; and this causes the negligence that is a mortal sin.
2. According to the same authority (gloss), a small offering made with a humble mind and out of pure love, cleanses man not only from venial but also from mortal sin.
3. When negligence consists in the omission of that which is necessary for salvation, it is drawn to the other more manifest genus of sin. Because those sins that consist of inward actions, are more hidden, wherefore no special sacrifices were prescribed for them in the Law, since the offering of sacrifices was a kind of public confession of sin, whereas hidden sins should not be confessed in public.
We must now consider those vices opposed to prudence, which have a resemblance thereto. Under this head there are eight points of inquiry:
(1) Whether prudence of the flesh is a sin?
(2) Whether it is a mortal sin?
(3) Whether craftiness is a special sin?
(4) Of guile;
(5) Of fraud;
(6) Of solicitude about temporal things;
(7) Of solicitude about the future;
(8) Of the origin of these vices.
Objection: 1. It would seem that prudence of the flesh is not a sin. For prudence is more excellent than the other moral virtues, since it governs them all. But no justice or temperance is sinful. Neither therefore is any prudence a sin.
2. Further, it is not a sin to act prudently for an end which it is lawful to love. But it is lawful to love the flesh, "for no man ever hated his own flesh" (Ep 5,29). Therefore prudence of the flesh is not a sin.
3. Further, just as man is tempted by the flesh, so too is he tempted by the world and the devil. But no prudence of the world, or of the devil is accounted a sin. Therefore neither should any prudence of the flesh be accounted among sins.
On the contrary No man is an enemy to God save for wickedness according to Sg 14,9, "To God the wicked and his wickedness are hateful alike." Now it is written (Rm 8,7): "The prudence [Vulg.: 'wisdom'] of the flesh is an enemy to God." Therefore prudence of the flesh is a sin.
I answer that As stated above (Question , Article ), prudence regards things which are directed to the end of life as a whole. Hence prudence of the flesh signifies properly the prudence of a man who looks upon carnal goods as the last end of his life. Now it is evident that this is a sin, because it involves a disorder in man with respect to his last end, which does not consist in the goods of the body, as stated above (I-II 2,5). Therefore prudence of the flesh is a sin.
Reply to Objection: 1. Justice and temperance include in their very nature that which ranks them among the virtues, viz. equality and the curbing of concupiscence; hence they are never taken in a bad sense. On the other hand prudence is so called from foreseeing [providendo], as stated above (Question , Article ; Question , Article ), which can extend to evil things also. Therefore, although prudence is taken simply in a good sense, yet, if something be added, it may be taken in a bad sense: and it is thus that prudence of the flesh is said to be a sin.
2. The flesh is on account of the soul, as matter is on account of the form, and the instrument on account of the principal agent. Hence the flesh is loved lawfully, if it be directed to the good of the soul as its end. If, however, a man place his last end in a good of the flesh, his love will be inordinate and unlawful, and it is thus that the prudence of the flesh is directed to the love of the flesh.
3. The devil tempts us, not through the good of the appetible object, but by way of suggestion. Wherefore, since prudence implies direction to some appetible end, we do not speak of "prudence of the devil," as of a prudence directed to some evil end, which is the aspect under which the world and the flesh tempt us, in so far as worldly or carnal goods are proposed to our appetite. Hence we speak of "carnal" and again of "worldly" prudence, according to Lc 16,8, "The children of this world are more prudent [Douay: 'wiser'] in their generation," etc. The Apostle includes all in the "prudence of the flesh," because we covet the external things of the world on account of the flesh.We may also reply that since prudence is in a certain sense called "wisdom," as stated above (Question , Article , ad 1), we may distinguish a threefold prudence corresponding to the three kinds of temptation. Hence it is written (Jc 3,15) that there is a wisdom which is "earthly, sensual and devilish," as explained above (Question , Article , ad 1), when we were treating of wisdom.
Summa Th. II-II EN Qu.53