IV. On the Comparative Gravity of the Sins

349. - 1. Because of the greater departure from nature, bestiality ¹ is the worst sin of lust among those which have a proper name, although the affection or will of lying with a demon contains a most grave malice against religion.

¹ St. Thomas, II-II, question 154, article 12; St. Alphonsus, book 3, no. 474; Lehmkuhl, I, 1047, and all authors.

But sodomy is worse than fornication.

And the enormity is so great that the absence of an accomplice and of offspring in bestiality, or of offspring alone in sodomy, cannot compensate for it. The matter stands otherwise in pollution, as we saw, no. 342.

2. But what is to be said of simple fornication and onanistic fornication when compared with each other?

The matter seems to us to be estimated from the affection. One who chooses onanistic intercourse so that he may harm the woman less is led by a less perverse affection than one who contemns the burdens to be undergone by the woman from childbirth, so that he may satisfy himself more fully.

But those who seek pleasure without the burden will sin more than those who determine to bear the connected burdens with a resigned mind, so that they may act according to nature.

350. - From the demonstration made, it is evident that acts of imperfect lust are specifically distinguished from the complete act when one stops at them; but if they are joined with the perfect act, these imperfect acts, which pertain to the same completed species, constitute, according to general principles, one sin both in species and in number. For the entire rationale of the specific distinction rested upon separation from the complete act. Conjunction removes this rationale of distinction, "just as a part of a movement is not distinguished from the whole movement when the movement is continuous, but only when the movement stops in the middle." St. Thomas, I-II, question 72, article 7, reply to objection 3.