Article III. On Bestiality

I. Notion. Bestiality is intercourse with a beast (St. Thomas, II-II, q. 154, a. 12, ad 4; St. Alphonsus III, 474). Now the essence and malice of this sin seems to consist in venereal mingling with an individual of a species with which the act of generating cannot be instituted. Hence for bestiality, equally and for the same reasons as for sodomy (n. 52), there are required: 1. an act placed after the manner of intercourse; 2. an act placed, by means of the genital member, on the part of the agent; 3. insertion of the genital member into some vessel of the beast, that is, into the natural vessel or into another. Moreover, it does not matter of what species or of what sex the beast was, "because the whole essential deformity of this crime consists in access to a diverse species" (St. Alphonsus III, 474).

Corollary I. Bestiality is not had if someone indecently touches a beast with the hand, or, for example, admits the tongue of a beast to his own private parts. Besides, intercourse with a beast which has not taken place in some vessel is not bestiality in act, although it will easily have annexed an affection toward bestiality.

Corollary II. If bestiality is reserved anywhere, it is understood as congress in the natural vessel of the beast, with effusion of semen made there.

II. Morality. Bestiality - equally and for the same reasons as pollution and sodomy (n. 5) - is intrinsically and gravely evil; indeed it is the gravest sin of lust, because through it a man is venereally mingled with a diverse species. Add these words of Sacred Scripture: "He who has intercourse with a beast or cattle, let him die the death; also kill the beast. - The woman who lies beneath any beast shall be killed together with it; their blood be upon them."¹

Note. Bestiality is committed more rarely in cities than in villages, by peasants, stablemen, and others who spend much time with beasts; more rarely by women than by men. If someone seems to have to be questioned, he can be asked whether the presence of animals was for him an occasion of sinning. If the confessor from the response notices that the penitent is free from this sin and perhaps ignorant of it, let him take care to shut out the idea of that sin, asking, for example, whether he acted cruelly toward animals.²

¹ Lev. 20:15-16; cf. Exod. 22:19.

² Aertnys, Theologia pastoralis, n. 38.