Article III. On The Sins Of Spouses

698. It is scarcely necessary to note that here there is discussion only of the sins of spouses against chastity.

Principle. a) A grave sin of spouses against chastity is whatever directly and gravely conflicts with the good of offspring and the good of fidelity; b) a venial sin is whatever is done from pleasure alone, without directly conflicting with the good of offspring and fidelity; c) no sin is that which is useful or necessary for performing the conjugal act well and fostering marital love.

Explanation. The second and third parts of this principle are sufficiently evident from what was said above, nn. 690 and 692, concerning the conjugal act performed from pleasure alone and concerning the accessories of this act. - Nearly all mortal sins of spouses can be reduced to three classes: 1. sins of lust perpetrated with other persons, whether by deed or by desire; 2. sodomy and onanistic intercourse; 3. solitary pollution. - There can be no special difficulty concerning the judgment of sins of the first and third classes. The same holds concerning those sins as must be said if they were perpetrated by an unmarried person. A new species, however, is added, namely, the violation of justice. For a spouse perpetrating these sins violates not only chastity but also justice, since he or she no longer has power over his or her own body, but the consort has it, who by divine institution cannot renounce this right. Hence a spouse who has committed, for example, pollution⁴⁰³ or sins with other persons must declare his or her conjugal state in confession. Nevertheless, in practice, because those who are untrained in moral matters do not apprehend the twofold malice in solitary pollution, the confessor can sometimes omit questions, unless he hopes that the penitent, warned of the greater gravity of the sin, will thereby be more effectively deterred from committing new sins.⁴⁰⁴ - Nor are many things to be said here concerning sodomy. For if sodomy is committed with another person, then the same holds as was just said concerning sins of lust committed outside matrimony. But if there is question of imperfect sodomy committed between the spouses themselves, then this must be accused altogether in confession. For it is a detestable abuse of matrimony.⁴⁰⁵

It remains to speak of conjugal onanism, and indeed: 1. of the notion and malice of conjugal onanism; 2. of cooperation in conjugal onanism; 3. of the means of guarding against conjugal onanism; 4. of the manner of treating spouses practicing onanism.

⁴⁰³ Some authors, such as Marc (Instit. mor. I, n. 793) and Noldin (De sexto praec., n. 31), call pollution perpetrated by one spouse adultery.

⁴⁰⁴ Cf. Noldin, ibid., n. 19.

⁴⁰⁵ What perfect and imperfect sodomy are, see above in the treatise on the virtue of chastity, II, n. 706. - Moralists ask here whether venereal pleasure had through touches and looks upon one's own body without danger of pollution is a mortal sin for spouses. Some respond that in all these things spouses are to be judged like unmarried persons; others, however, probably teach that for spouses in the matter of chastity a mortal sin is present only when pollution or its proximate danger arises. But all other things are not gravely sinful, because they can have some relation to conjugal intercourse. It is self-evident that spouses sin not more lightly but more gravely than unmarried persons in venereal pleasure which is referred to an extraneous person. Cf. Berardi, Praxis confess. I, n. 962.