Article II: On Luxury Against Nature

S. Th. II-II, q. 154, a. 5, 11 and 12.

1014. A sin of luxury against nature is that which repugns the order and mode which nature established in the venereal act for generation, to which alone it is ordered by nature; hence it is a distinct species of luxury, since it has a special deformity.

There are four subordinate species of it, including a diverse repugnance to nature and reason. For the venereal act, so that offspring can be conceived from it, requires four things: 1) the intercourse of two; 2) the same specific nature in each; 3) diversity of sexes; 4) the connatural mode of lying together. Therefore there are four species of sin against nature:

1. If, without intercourse, pollution is procured for the sake of venereal pleasure; this is called the solitary sin or mollities (zelfbevlekking);

2. If it happens through intercourse with a thing of a different species; this is called bestiality (beestachtigheid);

3. If it happens through intercourse with an undue sex, that is, with the same sex, for example male with male, or female with female; this is called sodomy properly so called (sodomieterij);

4. If, while the due sex is preserved, the due natural mode of lying together is not preserved, so that generation is impeded; this is unnatural intercourse with a woman (a. 11). This can happen in two ways: a) on the part of the organ: it is called sodomy improperly so called, if copulation happens in an undue organ, for example in the posterior vessel; b) on the part of the mode alone, if copulation is exercised in the due organ, but in such a way that, from the very mode by which the action is carried out, generation is impeded, either because the man withdraws himself before insemination and pours out seed externally, or because he or the woman uses an instrument or another means by which the seed is impeded from passing to the womb. It is usually called onanism.

Therefore sins against nature are morally distinct in species from one another, as repugning nature and reason in diverse ways; and the contrary was condemned by Alexander VII.¹

¹ Proposition 24 was condemned: "Mollities, sodomy, and bestiality are sins of the same lowest species; and therefore it suffices to say in confession that one procured pollution."

A mere change of the natural position in copulation is not against nature except insofar as generation would be impeded by it, which ordinarily does not happen; otherwise it will rather be beside nature than against nature, and is only venial in spouses and sometimes nothing, namely if some reason requires that it be done so.

1015. Luxury against nature is in the genus of luxury the gravest in itself and other things being equal, because it transgresses that which is determined according to nature itself concerning the use of venereal things; but the other sins transgress only that which is further determined by reason. Yet by reason of an added circumstance these can be graver in another genus: thus adultery by reason of injustice is graver than pollution, and sacrilege by reason of irreligion; but pollution is graver than both in the account of luxury (a. 12).

Among sins against nature, bestiality is the gravest, because the due species is not preserved; after this is sodomy, because there the due sex is not preserved; then there is an undue mode of lying together, but more if the due organ is not preserved, than if the mode alone is impeditive of generation; the lowest place is held by pollution, which consists only in the omission of intercourse with another. For the gravity of sin is considered more from the abuse of some thing than from the omission of due use (ad 4).

Let it be noted: 1) Sodomy is an execrable sin, as is clear both from the fact that even brute animals regularly abhor it, and from the graver penalties inflicted by ancient law or by God himself (Gen. 19). The same holds concerning bestiality, as is proved from the penalties laid down against it by God, for example, Lev. 20.

2. For these sins to be committed externally in their proper species, a mere touch exercised upon a person of the same sex or upon an animal is not sufficient, even with sodomitic or bestial affection; rather, intercourse to an undue vessel is required, whether it is not destined for coition or is naturally destined for it. Indeed, for them to be fully consummated in their species, insemination within the vessel is required.

3. Intercourse with a demon is reduced to bestiality, because the demon is of a different species from man: whether the demon really appears under a human form, which happens rarely, or the sinner, by hallucination, sets him before himself as present in this way. This sin additionally includes the malice of superstition against religion; then another diverse species of luxury according to the form under which the demon is seen by the sinner: if as a person of the same sex, the malice of sodomy is present; if as a person of a different sex, the malice of fornication; if under the form of another's spouse or of a nun, the malice of adultery or sacrilege, etc.

1016. Pollution, or the solitary sin, is the separated complete use of the genitals without intercourse. It is said:

1. Complete use of the genitals: for thus it is distinguished from immodesty or acts of imperfect luxury, which are only the beginning and preparation of complete luxury, and it differs from these in species, as the mere beginning of a work differs from consummation, beginning from terminus, and an incomplete species from a complete species;

2. Without intercourse, because if it happens in natural intercourse, it will be fornication or another species according to nature; if in unnatural intercourse, namely had in an undue organ, it will be another species against nature. Therefore from the fact that it is a solitary vice, or that it implies the separated use of the genital organ, pollution differs in species from other consummated sins according to and against nature.

The complete use of the genital organ is apt to produce perfect and satiative venereal pleasure; and in men, the expulsion of seed, which aggravates the sin comparatively to what takes place in women. Yet these two things do not constitute the essence of the solitary sin, but are a certain bad effect which usually accompanies it, and an indication and sign of the complete use of the genitals. But the essential inordination is in the perverse use of the genital organ, which someone employs for individual satisfaction, without any order to generation and the good of the species for the sake of which alone it can be employed. Hence the complete solitary sin also exists in women,1 and can exist in men if they do not have seed, as sometimes happens in the young and the old, or if accidentally it does not flow out externally.

1017. Pollution directly and in itself voluntary is intrinsically and gravely evil, and therefore prohibited by natural law, so that it can never be made honorable by any end. - It is proved:

1. From the Scriptures: 1 Cor. 6:10; Gal. 5:19; Eph. 5:².

² Hence, when the doubt was proposed: "whether masturbation directly procured so that sperm may be obtained by which a contagious disease may be scientifically detected and, as far as possible, cured is licit," the Holy Office responded: in the negative, 24 July 1929.

2. From the condemnation of proposition 49 by Innocent XI.³

³ "Mollities is not prohibited by natural law; hence if God had not forbidden it, it would often be good and sometimes obligatory under mortal sin."

3. By reason: This act is directly against the primary end to which the genital organs, venereal pleasure, and human seed are destined by nature and by the author of nature. Therefore a) it is an inordination intrinsically evil and illicit by the law of nature, so that it can never be made honorable by any end;3 b) it is also a grave or mortal inordination, because it is directly opposed to the primary inclination of our nature and to the greatest common good of human society, namely its conservation and propagation. Hence if fornication itself is a mortal sin because it is against the due education of offspring, a fortiori pollution, which is against propagation itself.

This is confirmed: "If in any case whatsoever it were licit to procure pollution for oneself or another, since in it men are affected with the greatest pleasure, they would easily abuse that license and extend it to almost infinite cases, and thus, content with that pleasure, they would neglect marriage and the legitimate mode of generating with the greatest detriment of the human species. Therefore in this, as in many other matters, one must not attend precisely to the actual harm which follows, but to the harm which would follow or would be apt to follow if this were licit."⁴

⁴ Some modern authors doubted concerning this, among whom was also Noldin; but in new editions of his work this was corrected by Fr. Schmitt.

Every pollution of itself is a sin of the same species, in whatever way it happens.

Accidentally, however, by reason of a special circumstance, another species can be added. Hence pollution is divided into simple, which besides the malice of pollution has no other malice joined; and qualified, which has another joined, either on the part of affection toward the object thought of, as if someone, while polluting himself, has a fornicarious, incestuous, adulterous, sacrilegious, sodomitic, etc. affection, by taking pleasure precisely in a woman, a blood relative, a married woman, one sacred to God, a male, as such, or by desiring them; or on the part of the person polluted or polluting, as if a religious, a married person, etc. pollutes himself or another, or is polluted by another. These circumstances, as adding a species, must be declared in confession.

1. Billuart, diss. VI, a. 11.

1018. Corollary. - The doctrine set forth applies to pollution directly and in itself voluntary; but not to pollution voluntary only in the cause or indirectly. For this is not always gravely evil, indeed not always a sin, as is clear from the principles set forth concerning the voluntary in the cause and the indirect, which are to be applied here.

1. It is not illicit to posit an action from which pollution is foreseen to follow, provided the action is licit in itself and at the same time necessary or useful, provided consent to the pollution or proximate danger of consent is absent. For no one is bound to omit an action licit in itself, necessary or useful for a good effect, because of some evil, not very great, following from it apart from intention, provided the evil is not the means for obtaining the good effect. But in the case the action, as is supposed, is licit in itself, and necessary or useful; the passive pollution following from it apart from intention is a rather slight evil, bringing little or altogether no inconvenience either to the acting individual or to the human species. Therefore the action is licit, provided the pollution is not the means by which the good effect is obtained.

2. It is a venial sin, without sufficient reason, to posit an action lightly evil and lightly and remotely influencing pollution which is foreseen to follow from it. For pollution, since it is not willed in itself, is not more voluntary and sinful than its cause as cause; but the cause as cause is only lightly evil, since its influence is only light and remote; for a light influence upon something grave is something light. Therefore pollution is only lightly evil; unless, however, there is proximate danger of consenting to it.

3. A fortiori it is only venial, without sufficient reason, not to impede depraved motions of concupiscence and pollution itself, while nevertheless it can be impeded without inconvenience; because in the case every tendency or positive consent of the will toward pollution is lacking; unless, however, there is proximate danger of consent to it.

4. It is mortal, by reason of pollution, without a just cause, to posit an action mortally evil from which pollution is perfectly foreseen naturally to follow, or an action which per se, notably, and proximately influences it so that it is apt to follow from it. For to will an effect and to will its proximate cause are of the same morality, unless there underlies a grave and just reason.

1019. Remark. - As to nocturnal pollution, its malice is to be weighed from its causes. Hence it either is or is not a sin according to the condition of the cause in which it was foreseen, or ought to have been foreseen. If the cause is not culpable, as if it is posited from a just reason, and a fortiori if it is merely natural, neither will the pollution itself be culpable; if the cause is culpable venially, lightly and remotely influencing it, it will be venial; if the cause is mortal, gravely and proximately influencing it, it will be mortal.