2 Peter 2:12

The inspired psalmist said this when he sang: "Man, when honored, had no understanding. He is like the beasts that perish." Although human beings had laws, their morals were irrational, and they soon degenerated into animals whose only end was destruction.

But these, like irrational animals naturally, etc. Just as it is natural for irrational animals to often ignorantly fall into traps and destruction out of the need for food, so heretics, compared to foolish beasts, out of a desire to fulfill their own corruption, blaspheming the incorrupt and sound doctrine of the Catholic Church and life, bind themselves with the snares of eternal perdition by impious recklessness. The ecclesiastical history reports that such heretics existed in the times of the apostles: the Simonians, Menandrians, Basilideans, Nicolaites, Ebionites, Marcionites, and Cerdonians, and many others. Rightly, having said of them: Blaspheming in their own corruption they shall perish, he added:

But like irrational brute creatures, born to be caught and destroyed, blaspheming in matters they do not understand, they will perish in their own corruption, receiving the wages of unrighteousness, as they count it pleasure to party in the daytime. And indeed the angels in this way. "But like irrational brute creatures," that is, living only by sense, not likewise by mind and intellectual life: for which reason they are easily captured by corruptible things, that is, by the movement in a corrupt life: the excitement of the soul and the desire acted upon and drawn, in those things which they are ignorant of or in their spontaneous ignorance bringing in curses, they will perish in their own corruption, receiving the wages of unrighteousness, that is, that which they have acquired for themselves. "for the sake of pleasure as they count it pleasure to party in the daytime ." Indeed, they truly desire, placing true and desirable joy and pleasure in the daily enjoyment of the palate. Therefore, it should be known that when sacred Scripture reproaches something, it assimilates to brute beings those things which naturally happen to men, that is, those which occur to them as animals, saying: "Man, when he was in honor, did not understand; he was compared to the senseless beasts (Ps. 48:37);" and: "Do not be like a horse and a mule (Ps. 31:9);" and: "The horses became mad for the mares (Jer. 5:8);" and: "Be wise as serpents and innocent as doves (Matt. 5:16);" not that by saying this it changes natures, for that is impossible, but it invites them to avoid these indeed natural inclinations of theirs, while embracing those naturally. When, however, it prescribes something salutary, it transmits the likeness to better things: as when it says: "Be merciful as your heavenly Father," (Luke 6:26) not even here transforming nature, but commanding to do this as much as virtue suggests.