Article III: Concerning Adultery

I. Adultery¹ (overspel, echtbreuk) is, as it were, an approach to another bed, and therefore can be defined: the violation of another's bed, or copulation with the spouse of another. But if both are married, there will be a twofold malice of adultery to be declared in confession; for each one commits his own sin of adultery and, besides, by complicity cooperates in the adultery of the other. If he did not declare this in confession, he would deceive the confessor.

¹ Concerning adultery, these can usefully be consulted: Revue Eccl. de Liege, VII, January 1912: "Les effets de l'adultere"; and Loslever, Amour libre ou Fidelite.

II. Adultery, even when had only on one side, is a distinct species of lust because it includes a twofold grave malice: one against chastity, the other against justice, by violating the fidelity promised in marriage and the right over the body acquired by the spouse, while that which belongs to the spouse as to use is given to another. The co-adulterous party cooperates in this infidelity and injustice. Hence, besides the deformity of fornication, which it has from the fact that someone approaches one not his own and impedes the good of educating his own offspring, it has a deformity from this, that he approaches another's and thus impedes the good of another's offspring.² For this reason it also contains indistinctly a malice against religion, if the marriage is a sacrament; against piety, by breaking the unity of which each spouse is a part; and against the common good.

² Saint Thomas, II-II, q. 154, a. 8.

Hence it is a very grave sin, as is clear from the manner of speaking of Scripture: Lev. XVIII, 20; XX, 10; Deut. XXII, 22-24; Tob. IV, 13; Prov. VI, 29; Eccli. XXIII, 25-29; I Cor. VI, 9; and from the penalties of civil law.

III. Adultery is committed in three ways, and therefore three degrees are distinguished in it: the first is that of a married man with an unmarried woman; the second, of a married woman with an unmarried man; the third, of a married man with a married woman. The second is of itself graver than the first, because it is more repugnant for one woman to be mingled with several men than for one man with several women. For:

a. from mingling with several men the woman is usually made sterile and generation is impeded; but if it is not impeded, it is uncertain whose the offspring is;

b. the adulteress exposes herself to the danger of introducing illegitimate offspring into the family, with great harm to the husband and to the legitimate children, who are thereby deprived of part of the inheritance. See the treatise on justice. But all these things do not follow from the adultery of a married man with an unmarried woman.

The third degree is the gravest of all, because beyond the aforesaid things it contains a twofold malice of infidelity and a twofold malice of injustice.

IV. Adultery is also a special sin if the other spouse consents, as is evident from proposition 50 condemned by Innocent XI.³ For although no injury is done to this one, as knowing and consenting, who, so far as he is concerned, has renounced his right or does not oppose it, nevertheless that right, arising from a contract for the public good, necessarily cannot be perfectly alienated, and much less the right of God or of society. Namely, the husband does not have an absolute right over the use of the wife's body, but an exclusionary right limited to the licit use of marriage. Hence the conjugal right remains whole, concerning which the spouses cannot yield, and therefore, although injury is not done to the husband, nevertheless there remains injury done to the state and right of marriage.

³ "Copulation with a married woman, with the husband consenting, is not adultery; and therefore it suffices in confession to say that one has fornicated."

V. Observation. Copulation had with a person betrothed to another, from valid betrothals, implies a notably aggravating circumstance. Nevertheless, as it seems, the species is not changed, because the betrothed man does not yet have a strict right over the body of the betrothed woman. Such copulation is graver in the betrothed woman than in the betrothed man, because the betrothed woman is thereby notably less esteemed.