Cross reference
Jude 1:10
10 and these, as many things indeed as they have not known, they speak evil of; and as many things as naturally (as the irrational beasts) they understand, in these they are corrupted;
2 Peter 2:12
12 and these, as irrational natural beasts, made to be caught and destroyed -- in what things they are ignorant of, speaking evil -- in their destruction shall be destroyed,
Romans 1:21-22
21 because, having known God they did not glorify `Him' as God, nor gave thanks, but were made vain in their reasonings, and their unintelligent heart was darkened,
22 professing to be wise, they were made fools,