Thomas Aquinas

“ The wife's repentance should induce the husband not to accuse or put away the wife who is guilty of fornication. He cannot, however, be compelled to this course of action, nor can his wife oppose her repentance to his accusation, because although she is no longer guilty, neither in act nor in the stain of sin, there still remains something of the debt of punishment, and though this has been taken away in the sight of God, there still remains the debt of punishment to be inflicted by the judgment of man, because man sees not the heart as God does. ”

“ For divorce is a punishment of adultery, in so far as it is opposed to the marriage goods. Now as regards the good of fidelity to which husband and wife are equally bound towards each other, the adultery of one is as great a sin against marriage as the adultery of the other, and this is in either of them a sufficient reason for divorce. ”

“ In adultery there is the same sinful character as in simple fornication, and something more which aggravates it, namely the lesion to marriage. Accordingly if we consider that which is common to adultery and fornication, the sin of the husband and that of the wife are compared the one to the other as that which exceeds to that which is exceeded, for in women the humors are more abundant, wherefore they are more inclined to be led by their concupiscences, whereas in man there is abundance of heat which excites concupiscence. ”

“ Divorce on account of fornication is effected by the one accusing the other. And since no one can accuse who is guilty of the same crime, a divorce cannot be pronounced when both have committed fornication, although marriage is more sinned against when both are guilty of fornication that when only one is. ”

“ Further, where there is greater injury to one's neighbor, there is a greater sin. Now the adulterous wife does a greater injury to her husband, than does the adulterous husband to his wife, since a wife's adultery involves uncertainty of the offspring, whereas the husband's adultery does not. Therefore the wife's sin is the greater, and so they ought not to be judged on a par with each other. ”

“ The only reason why divorce was permitted, was to avoid murder. And since there was more danger of this in men than in women, the husband was allowed to put away his wife by a bill of divorce, but not "vice versa." ”

“ Further, one can always pardon the sin that another has committed against oneself. Now the wife, by committing fornication, sinned against her husband. Therefore the husband may spare her by not putting her away. ”

“ Now a man cannot at once be a member of a harlot and a member of Christ (1 Cor. 6:15) . Therefore the husband who is joined to a wife guilty of fornication ceases to be a member of Christ, and therefore sins mortally.
Objection 4: Further, just as relationship voids the marriage tie, so does fornication dissolve the marriage-bed. Now after the husband becomes cognizant of his consanguinity with his wife, he sins mortally if he has carnal intercourse with her. Therefore he also sins mortally if he does so after knowing her to be guilty of fornication. ”

“ A husband sins if through vindictive anger he puts away his wife who has committed fornication, but he does not sin if he does so in order to avoid losing his good name, lest he seem to share in her guilt, or in order to correct his wife's sin, or in order to avoid the uncertainty of her offspring. ”

“ The wife can be corrected for her sin of fornication not only by this punishment but also by words and blows; wherefore if she be ready to be corrected otherwise, her husband is not bound to have recourse to the aforesaid punishment in order to correct her. ”

“ Now there is greater frailty in women than in men, for which reason Chrysostom [*Hom. xl in the Opus Imperfectum falsely ascribed to St. John Chrysostom] says that "lust is a passion proper to women," and the Philosopher says (Ethic. vii, 7) that "properly speaking women are not said to be continent on account of their being easily inclined to concupiscence," for neither can dumb animals be continent, because they have nothing to stand in the way of their desires. Therefore women are rather to be spared in the punishment of divorce. ”

“ Because one may take steps for procuring a divorce on account of one act of carnal fornication, not, however, on account of one act of unbelief, but on account of inveterate unbelief which is a proof of obstinacy wherein unbelief is perfected. ”