John Calvin Commentary Jude 1:10

"But these rail at whatsoever things they know not: and what they understand naturally, like the creatures without reason, in these things are they destroyed." — Jude 1:10 (ASV)

But these speak evil of those things which they know not. He means that they had no taste for anything but what was gross and, as it were, beastly, and therefore did not perceive what was worthy of honor. Yet, they still added audacity to madness, so that they did not fear to condemn things beyond their comprehension.

They also suffered from another evil—for when, like beasts, they were carried away by those things that gratified their physical senses, they showed no moderation, but gorged themselves excessively, like swine that roll themselves in stinking mud.

The adverb naturally is contrasted with reason and judgment, for the instinct of nature alone rules in brute animals; but reason ought to govern humans and bridle their appetites.