Summa Theologica, by St. Thomas Aquinas, [1947], at sacred-texts.com
We must next consider the vice of lust which is opposed to chastity: (1) Lust in general; (2) its species. Under the first head there are five points of inquiry:
(1) What is the matter of lust?
(2) Whether all copulation is unlawful?
(3) Whether lust is a mortal sin?
(4) Whether lust is a capital vice?
(5) Concerning its daughters.
Objection 1: It would seem that the matter of lust is not only venereal desires and pleasures. For Augustine says (Confess. ii, 6) that "lust affects to be called surfeit and abundance." But surfeit regards meat and drink, while abundance refers to riches. Therefore lust is not properly about venereal desires and pleasures.
Objection 2: Further, it is written (Prov. 20:1): "Wine is a lustful [Douay: 'luxurious'] thing." Now wine is connected with pleasure of meat and drink. Therefore these would seem to be the matter of lust.
Objection 3: Further, lust is defined "as the desire of wanton pleasure" [*Alexander of Hales, Summ. Theol. ii, cxvli]. But wanton pleasure regards not only venereal matters but also many others. Therefore lust is not only about venereal desires and pleasures.
On the contrary, To the lustful it is said (De Vera Relig. iii [*Written by St. Augustine]): "He that soweth in the flesh, of the flesh shall reap corruption." Now the sowing of the flesh refers to venereal pleasures. Therefore these belong to lust.
I answer that, As Isidore says (Etym. x), "a lustful man is one who is debauched with pleasures." Now venereal pleasures above all debauch a man's mind. Therefore lust is especially concerned with such like pleasures.
Reply to Objection 1: Even as temperance chiefly and properly applies to pleasures of touch, yet consequently and by a kind of likeness is referred to other matters, so too, lust applies chiefly to venereal pleasures, which more than anything else work the greatest havoc in a man's mind, yet secondarily it applies to any other matters pertaining to excess. Hence a gloss on Gal. 5:19 says "lust is any kind of surfeit."
Reply to Objection 2: Wine is said to be a lustful thing, either in the sense in which surfeit in any matter is ascribed to lust, or because the use of too much wine affords an incentive to venereal pleasure.
Reply to Objection 3: Although wanton pleasure applies to other matters, the name of lust has a special application to venereal pleasures, to which also wantonness is specially applicable, as Augustine remarks (De Civ. xiv, 15,16).
Objection 1: It would seem that no venereal act can be without sin. For nothing but sin would seem to hinder virtue. Now every venereal act is a great hindrance to virtue. For Augustine says (Soliloq. i, 10): "I consider that nothing so casts down the manly mind from its height as the fondling of a woman, and those bodily contacts." Therefore, seemingly, no venereal act is without sin.
Objection 2: Further, any excess that makes one forsake the good of reason is sinful, because virtue is corrupted by "excess" and "deficiency" as stated in Ethic. ii, 2. Now in every venereal act there is excess of pleasure, since it so absorbs the mind, that "it is incompatible with the act of understanding," as the Philosopher observes (Ethic. vii, 11); and as Jerome [*Origen, Hom. vi in Num.; Cf. Jerome, Ep. cxxiii ad Ageruch.] states, rendered the hearts of the prophets, for the moment, insensible to the spirit of prophecy. Therefore no venereal act can be without sin.
Objection 3: Further, the cause is more powerful than its effect. Now original sin is transmitted to children by concupiscence, without which no venereal act is possible, as Augustine declares (De Nup. et Concup. i, 24). Therefore no venereal act can be without sin.
On the contrary, Augustine says (De Bono Conjug. xxv): "This is a sufficient answer to heretics, if only they will understand that no sin is committed in that which is against neither nature, nor morals, nor a commandment": and he refers to the act of sexual intercourse between the patriarchs of old and their several wives. Therefore not every venereal act is a sin.
I answer that, A sin, in human acts, is that which is against the order of reason. Now the order of reason consists in its ordering everything to its end in a fitting manner. Wherefore it is no sin if one, by the dictate of reason, makes use of certain things in a fitting manner and order for the end to which they are adapted, provided this end be something truly good. Now just as the preservation of the bodily nature of one individual is a true good, so, too, is the preservation of the nature of the human species a very great good. And just as the use of food is directed to the preservation of life in the individual, so is the use of venereal acts directed to the preservation of the whole human race. Hence Augustine says (De Bono Conjug. xvi): "What food is to a man's well being, such is sexual intercourse to the welfare of the whole human race." Wherefore just as the use of food can be without sin, if it be taken in due manner and order, as required for the welfare of the body, so also the use of venereal acts can be without sin, provided they be performed in due manner and order, in keeping with the end of human procreation.
Reply to Objection 1: A thing may be a hindrance to virtue in two ways. First, as regards the ordinary degree of virtue, and as to this nothing but sin is an obstacle to virtue. Secondly, as regards the perfect degree of virtue, and as to this virtue may be hindered by that which is not a sin, but a lesser good. In this way sexual intercourse casts down the mind not from virtue, but from the height, i.e. the perfection of virtue. Hence Augustine says (De Bono Conjug. viii): "Just as that was good which Martha did when busy about serving holy men, yet better still that which Mary did in hearing the word of God: so, too, we praise the good of Susanna's conjugal chastity, yet we prefer the good of the widow Anna, and much more that of the Virgin Mary."
Reply to Objection 2: As stated above (Q[152], A[2], ad 2; FS, Q[64], A[2]), the mean of virtue depends not on quantity but on conformity with right reason: and consequently the exceeding pleasure attaching to a venereal act directed according to reason, is not opposed to the mean of virtue. Moreover, virtue is not concerned with the amount of pleasure experienced by the external sense, as this depends on the disposition of the body; what matters is how much the interior appetite is affected by that pleasure. Nor does it follow that the act in question is contrary to virtue, from the fact that the free act of reason in considering spiritual things is incompatible with the aforesaid pleasure. For it is not contrary to virtue, if the act of reason be sometimes interrupted for something that is done in accordance with reason, else it would be against virtue for a person to set himself to sleep. That venereal concupiscence and pleasure are not subject to the command and moderation of reason, is due to the punishment of the first sin, inasmuch as the reason, for rebelling against God, deserved that its body should rebel against it, as Augustine says (De Civ. Dei xiii, 13).
Reply to Objection 3: As Augustine says (De Civ. Dei xiii, 13), "the child, shackled with original sin, is born of fleshly concupiscence (which is not imputed as sin to the regenerate) as of a daughter of sin." Hence it does not follow that the act in question is a sin, but that it contains something penal resulting from the first sin.
Objection 1: It would seem that lust about venereal acts cannot be a sin. For the venereal act consists in the emission of semen which is the surplus from food, according to the Philosopher (De Gener. Anim. i, 18). But there is no sin attaching to the emission of other superfluities. Therefore neither can there be any sin in venereal acts.
Objection 2: Further, everyone can lawfully make what use he pleases of what is his. But in the venereal act a man uses only what is his own, except perhaps in adultery or rape. Therefore there can be no sin in venereal acts, and consequently lust is no sin.
Objection 3: Further, every sin has an opposite vice. But, seemingly, no vice is opposed to lust. Therefore lust is not a sin.
On the contrary, The cause is more powerful than its effect. Now wine is forbidden on account of lust, according to the saying of the Apostle (Eph. 5:18), "Be not drunk with wine wherein is lust [Douay: 'luxury']." Therefore lust is forbidden.
Further, it is numbered among the works of the flesh: Gal. 5:19 [Douay: 'luxury'].
I answer that, The more necessary a thing is, the more it behooves one to observe the order of reason in its regard; wherefore the more sinful it becomes if the order of reason be forsaken. Now the use of venereal acts, as stated in the foregoing Article, is most necessary for the common good, namely the preservation of the human race. Wherefore there is the greatest necessity for observing the order of reason in this matter: so that if anything be done in this connection against the dictate of reason's ordering, it will be a sin. Now lust consists essentially in exceeding the order and mode of reason in the matter of venereal acts. Wherefore without any doubt lust is a sin.
Reply to Objection 1: As the Philosopher says in the same book (De Gener. Anim. i, 18), "the semen is a surplus that is needed." For it is said to be superfluous, because it is the residue from the action of the nutritive power, yet it is needed for the work of the generative power. But the other superfluities of the human body are such as not to be needed, so that it matters not how they are emitted, provided one observe the decencies of social life. It is different with the emission of semen, which should be accomplished in a manner befitting the end for which it is needed.
Reply to Objection 2: As the Apostle says (1 Cor. 6:20) in speaking against lust, "You are bought with a great price: glorify and bear God in your body." Wherefore by inordinately using the body through lust a man wrongs God Who is the Supreme Lord of our body. Hence Augustine says (De Decem. Chord. 10 [*Serm. ix (xcvi de Temp.)]): "God Who thus governs His servants for their good, not for His, made this order and commandment, lest unlawful pleasures should destroy His temple which thou hast begun to be."
Reply to Objection 3: The opposite of lust is not found in many, since men are more inclined to pleasure. Yet the contrary vice is comprised under insensibility, and occurs in one who has such a dislike for sexual intercourse as not to pay the marriage debt.
Objection 1: It seems that lust is not a capital vice. For lust is apparently the same as "uncleanness," according to a gloss on Eph. 5:3 (Cf. 2 Cor. 12:21). But uncleanness is a daughter of gluttony, according to Gregory (Moral. xxxi, 45). Therefore lust is not a capital vice.
Objection 2: Further, Isidore says (De Summo Bono ii, 39) that "as pride of mind leads to the depravity of lust, so does humility of mind safeguard the chastity of the flesh." Now it is seemingly contrary to the nature of a capital vice to arise from another vice. Therefore lust is not a capital vice.
Objection 3: Further, lust is caused by despair, according to Eph. 4:19, "Who despairing, have given themselves up to lasciviousness." But despair is not a capital vice; indeed, it is accounted a daughter of sloth, as stated above (Q[35], A[4], ad 2). Much less, therefore, is lust a capital vice.
On the contrary, Gregory (Moral. xxxi, 45) places lust among the capital vices.
I answer that, As stated above (Q[148], A[5]; FS, Q[84], AA[3],4), a capital vice is one that has a very desirable end, so that through desire for that end, a man proceeds to commit many sins, all of which are said to arise from that vice as from a principal vice. Now the end of lust is venereal pleasure, which is very great. Wherefore this pleasure is very desirable as regards the sensitive appetite, both on account of the intensity of the pleasure, and because such like concupiscence is connatural to man. Therefore it is evident that lust is a capital vice.
Reply to Objection 1: As stated above (Q[148], A[6]), according to some, the uncleanness which is reckoned a daughter of gluttony is a certain uncleanness of the body, and thus the objection is not to the point. If, however, it denote the uncleanness of lust, we must reply that it is caused by gluttony materially---in so far as gluttony provides the bodily matter of lust---and not under the aspect of final cause, in which respect chiefly the capital vices are said to be the cause of others.
Reply to Objection 2: As stated above (Q[132], A[4], ad 1), when we were treating of vainglory, pride is accounted the common mother of all sins, so that even the capital vices originate therefrom.
Reply to Objection 3: Certain persons refrain from lustful pleasures chiefly through hope of the glory to come, which hope is removed by despair, so that the latter is a cause of lust, as removing an obstacle thereto, not as its direct cause; whereas this is seemingly necessary for a capital vice.
Objection 1: It would seem that the daughters of lust are unfittingly reckoned to be "blindness of mind, thoughtlessness, inconstancy, rashness, self-love, hatred of God, love of this world and abhorrence or despair of a future world." For mental blindness, thoughtlessness and rashness pertain to imprudence, which is to be found in every sin, even as prudence is in every virtue. Therefore they should not be reckoned especially as daughters of lust.
Objection 2: Further, constancy is reckoned a part of fortitude, as stated above (Q[128], ad 6; Q[137], A[3]). But lust is contrary, not to fortitude but to temperance. Therefore inconstancy is not a daughter of lust.
Objection 3: Further, "Self-love extending to the contempt of God" is the origin of every sin, as Augustine says (De Civ. Dei xiv, 28). Therefore it should not be accounted a daughter of lust.
Objection 4: Further, Isidore [*QQ. in Deut., qu. xvi] mentions four, namely, "obscene," "scurrilous," "wanton" and "foolish talking." There the aforesaid enumeration would seem to be superfluous.
On the contrary, stands the authority of Gregory (Moral. xxxi, 45).
I answer that, When the lower powers are strongly moved towards their objects, the result is that the higher powers are hindered and disordered in their acts. Now the effect of the vice of lust is that the lower appetite, namely the concupiscible, is most vehemently intent on its object, to wit, the object of pleasure, on account of the vehemence of the pleasure. Consequently the higher powers, namely the reason and the will, are most grievously disordered by lust.
Now the reason has four acts in matters of action. First there is simple understanding, which apprehends some end as good, and this act is hindered by lust, according to Dan. 13:56, "Beauty hath deceived thee, and lust hath perverted thy heart." In this respect we have "blindness of mind." The second act is counsel about what is to be done for the sake of the end: and this is also hindered by the concupiscence of lust. Hence Terence says (Eunuch., act 1, sc. 1), speaking of lecherous love: "This thing admits of neither counsel nor moderation, thou canst not control it by counseling." In this respect there is "rashness," which denotes absence of counsel, as stated above (Q[53], A[3]). The third act is judgment about the things to be done, and this again is hindered by lust. For it is said of the lustful old men (Dan. 13:9): "They perverted their own mind . . . that they might not . . . remember just judgments." In this respect there is "thoughtlessness." The fourth act is the reason's command about the thing to be done, and this also is impeded by lust, in so far as through being carried away by concupiscence, a man is hindered from doing what his reason ordered to be done. [To this "inconstancy" must be referred.] [*The sentence in brackets is omitted in the Leonine edition.] Hence Terence says (Eunuch., act 1, sc. 1) of a man who declared that he would leave his mistress: "One little false tear will undo those words."
On the part of the will there results a twofold inordinate act. One is the desire for the end, to which we refer "self-love," which regards the pleasure which a man desires inordinately, while on the other hand there is "hatred of God," by reason of His forbidding the desired pleasure. The other act is the desire for the things directed to the end. With regard to this there is "love of this world," whose pleasures a man desires to enjoy, while on the other hand there is "despair of a future world," because through being held back by carnal pleasures he cares not to obtain spiritual pleasures, since they are distasteful to him.
Reply to Objection 1: According to the Philosopher (Ethic. vi, 5), intemperance is the chief corruptive of prudence: wherefore the vices opposed to prudence arise chiefly from lust, which is the principal species of intemperance.
Reply to Objection 2: The constancy which is a part of fortitude regards hardships and objects of fear; but constancy in refraining from pleasures pertains to continence which is a part of temperance, as stated above (Q[143]). Hence the inconstancy which is opposed thereto is to be reckoned a daughter of lust. Nevertheless even the first named inconstancy arises from lust, inasmuch as the latter enfeebles a man's heart and renders it effeminate, according to Osee 4:11, "Fornication and wine and drunkenness take away the heart [Douay: 'understanding']." Vegetius, too, says (De Re Milit. iii) that "the less a man knows of the pleasures of life, the less he fears death." Nor is there any need, as we have repeatedly stated, for the daughters of a capital vice to agree with it in matter (cf. Q[35], A[4], ad 2; Q[118], A[8], ad 1; Q[148], A[6]).
Reply to Objection 3: Self-love in respect of any goods that a man desires for himself is the common origin of all sins; but in the special point of desiring carnal pleasures for oneself, it is reckoned a daughter of lust.
Reply to Objection 4: The sins mentioned by Isidore are inordinate external acts, pertaining in the main to speech; wherein there is a fourfold inordinateness. First, on account of the matter, and to this we refer "obscene words": for since "out of the abundance of the heart the mouth speaketh" (Mat. 12:34), the lustful man, whose heart is full of lewd concupiscences, readily breaks out into lewd words. Secondly, on account of the cause: for, since lust causes thoughtlessness and rashness, the result is that it makes a man speak without weighing or giving a thought to his words. which are described as "scurrilous." Thirdly, on account of the end: for since the lustful man seeks pleasure, he directs his speech thereto, and so gives utterance to "wanton words." Fourthly, on account of the sentiments expressed by his words, for through causing blindness of mind, lust perverts a man's sentiments, and so he gives way "to foolish talking," for instance, by expressing a preference for the pleasures he desires to anything else.