§ 1. On the End.

78. There are several ends on account of which the conjugal act can be exercised; some of these are proper and essential, others improper and accidental. The proper ends are: a. for generating offspring; b. for avoiding incontinence or quieting libido; c. for satisfying the obligation toward the other spouse. Of these essential ends the first indeed, the generation of offspring, is the primary end; the others are secondary ends of marriage. Besides this threefold proper end, there are other improper ends, e.g. for conserving and fostering mutual love, for preserving or recovering health of body, etc.

1. The conjugal act can licitly be exercised on account of any honorable end whatever. If a proper end is in question, the reason is that an action fitting to nature is licitly exercised on account of those ends for which the author of nature instituted it. But if an improper end is in question, the reason is that an action not evil can licitly be applied to an honorable end for the obtaining of which it is useful.

a. There are those who with St. Thomas say that the conjugal act performed for avoiding one's own incontinence, not the spouse's, is a venial sin.¹ But in truth a. this end is not only honorable and laudable in itself, but also belongs to the essential ends of marriage; but to exercise an act indifferent in itself on account of an honorable end cannot be sin. b. St. Paul teaches that this end was intended by God in instituting marriage, 1 Cor. 7, 2, 5, and since the Apostle assigns this end alone to the conjugal act, he manifestly supposes that the work of marriage performed for this end alone is licit. c. The Church blesses the nuptials of old persons whom it knows to enter marriage for avoiding their own incontinence; this indeed the Church could not do if the use of marriage performed on account of that end were illicit.²

b. To exercise the conjugal act with affection toward another person whom one represents to himself, so that from that person he may take venereal delectation, is mental adultery and therefore a grave sin. In the conjugal act to represent another person to oneself, so that from that person's beauty one may take delectation and be excited to the conjugal act, is indeed not a sin but is very dangerous. Finally, if spouses put beautiful images before their eyes and look at them, either to excite themselves or to conceive more beautiful offspring, they do not commit sin, provided the images are not sacred.

2. To exercise the conjugal act on account of pleasure alone is a venial sin: for it is a disorder, although not grave, to will to rest in some thing as an end which the author of nature willed as a means to an end.³

But if no honorable end is positively intended, and the conjugal act occurs with this positive intention of taking pleasure, the act seems to have to be called honorable, provided in its exercise nothing is exceeded on any side against the prescriptions of reason, and the act is apprehended as licit or at least not as illicit. For the act itself is licit; the delectation which is sought is likewise licit; in the manner of exercising the act and taking pleasure, the order prescribed by reason is preserved, i.e. concupiscence is ruled by reason and will. Therefore nothing is understood to be lacking to the act that would prevent it from being fitting to rational nature and therefore orderable and objectively ordered to God, the ultimate end.⁴

Whether the conjugal act is licit if it is established that the woman will suffer miscarriage or bring forth dead offspring. It must be affirmed, at least if it is done for avoiding the danger of incontinence: for on the one hand, even for such offspring it is better to exist with original sin than not to exist at all; on the other hand, exclusion from supernatural beatitude is permitted by the parents from a grave cause, for avoiding the sin of incontinence.

3. It is not necessary that spouses in the use of marriage will the generation of offspring; indeed, from a just cause they can wish that it not be generated and from this desire restrict the use of marriage to that time at which there is less hope of future conception. Nevertheless, it is required that the intention of offspring not be positively excluded, i.e. that nothing be done by which offspring is impeded, but that the order of generation be preserved.

¹ Supplementum, q. 49, a. 5.

² Cf. Roman Catechism, pr. 2, c. 8, q. 14; St. Alphonsus, n. 882.

³ This proposition, 9, was condemned by Innocent XI: "The work of marriage exercised on account of pleasure alone is entirely without all fault and venial defect."

⁴ De principiis^3, n. 87 ff.