Matthew Henry Presbyterian @wholebiblehenry

Note, I. As the prevalency of men's lusts is owing to the darkness of their understandings, so the darkness of their understandings is very much owing to the dominion of their lusts: Men understand not judgment, discern not between truth and falsehood, right and wrong; they understand not the law of God as the rule either of their duty or of their doom; and, 1.

John Gill Reformed Baptist @doctorgill

Evil men understand not judgment,.... Or, "men of wickedness" (b); that are under the governing power of it; who are given up and give up themselves unto it; who, like Ahab, sell themselves to work wickedness: these know not what is just and right between man and man, at least not to do it; they know it not practically; they are wise to do evil...

Jamieson-Fausset-Brown Reformed @jfbcommentary

(Compare Joh 7:17). Ignorance of moral truth is due to unwillingness to know it.