§ 2. On Situation and Place.

79. On situation. The natural and ordinary situation of the conjugal act is this, that it occur lying down, in such a way that the woman lies beneath and the man lies above: for this situation is most apt for the infusion of semen into the vessel of the woman. Any situation is unnatural which departs from the natural one, as if intercourse occurs sitting or standing, or in such a way that the man lies beneath and the woman lies above. Through an unnatural situation generation is indeed rendered more difficult, but not impossible, because the semen reaches the ovaries not by descent, but by attraction.¹

To choose a mode of coming together by which conception is actually rendered more difficult, from the intention of rendering conception more difficult, is a venial sin if it is done without a just cause: for since the generation of offspring is the primary end of marriage, to act thus without a just cause is against reason; nevertheless not gravely, because conception is not impeded.

1. An unnatural situation, whatever it may be, does not exceed venial sin, provided grave danger of pouring forth semen outside the vessel is excluded: for any situation by which intercourse can be had is apt for generation.

Therefore spouses must never be questioned concerning the situation which they employ in performing the conjugal act, since the matter is not necessary for confession; and if the penitents themselves ask about this matter for the sake of counsel, let the confessor respond only in general, that they complete the act duly and, as far as can be done, in the natural mode. But if penitents accuse themselves concerning an unnatural situation, let him ask whether generation could have followed from that intercourse, because it suffices for the confessor to know whether generation was altogether impeded.

2. If a change of the natural situation is done from a just cause, e.g. on account of danger of miscarriage or on account of difficulty of coming together in the natural mode, there is no sin, even if some part of the semen is scattered; indeed, if another mode of intercourse is impossible, even if a great part of the semen is lost: for on the one hand the scattering occurs accidentally, and on the other hand generation is not impeded, since a small part of semen suffices for it.²

¹ St. Alphonsus, n. 917; Capellmann, Medicina past.^9, p. 151.

² Capellmann, Medicina pastor., p. 151.

80. On place. 1. Natural shame and the law of charity, by which we must avoid scandal, require that the place be secret.

a. To have intercourse before others is a grave sin by reason of scandal.

b. Parents ought to take care lest children acquire knowledge of this matter and thus suffer scandal.

2. In a sacred place ecclesiastical law prohibits intercourse under grave sin, unless necessity presses: for through the effusion of human semen irreverence is inflicted on the sacred place, and if the effusion becomes notorious, the church is polluted.¹

¹ Cf. St. Alphonsus, l. 3, n. 458; cf. De praeceptis^3, n. 178.