Pius XI, 1922-1939

any honorable use of this faculty given by God to procreate new life, at the command of the Creator Himself and the laws of nature, is the right and privilege of matrimony alone, and must be confined within the sacred limits of marriage.

2231. [2] Another blessing of matrimony which we have spoken of as mentioned by Augustine, is the blessing of faith, which is the mutual fidelity of spouses in fulfilling the marriage contract, so that what by this contract, sanctioned by divine law, is due only to one spouse, cannot be denied him nor permitted to anyone else; nor is that to be conceded to the spouse, which can never be conceded, since it is contrary to divine rights and laws and is especially opposed to conjugal faith.

Thus this faith demands in the first place the absolute unity of marriage, which the Creator Himself established in the matrimony of our first parents when He willed that it exist only between one man and one woman. And although afterwards God, the supreme legislator, somewhat relaxed this primeval law for a time, nevertheless there is no doubt that the Evangelical Law entirely restored that original and perfect unity and did away with all dispensations, as the words of Christ and the uniform way either of teaching or acting on the part of the Church plainly show [see note 969]. . . .

Nor did Christ the Lord wish to condemn only polygamy and polyandry, whether successive ¹ or simultaneous, as they are called, or any other dishonorable act; but, in order that the sacred bonds of marriage may be absolutely inviolate, He forbade also even the willful thoughts and desires about all these things: "But I say to you that whosoever shall look on a woman to lust after her hath already committed adultery with her in his heart" [Matt. 5:28]. These words of Christ the Lord cannot become void even by the consent of one spouse; for they express the law of God and of nature, which no will of man can ever break or bend.²

Even mutual familiar intercourse between spouses, that the blessing of conjugal faith may shine with due splendor, should be so distinguished by the mark of chastity that husband and wife conduct themselves in all things according to the law of God and of nature, and strive always to follow the will of the most wise and most holy Creator, with great reverence for the work of God.

2232. Moreover, this conjugal fidelity, most aptly called by St. Augustine ³ the "faith of chastity," will flourish more readily, and even much more pleasantly, and as ennobling coming from another most excellent source, namely, from conjugal love, which pervades all duties of the married life