Because, when they knew God, they glorified him not as God, neither were thankful; but became vain in their imaginations, and their foolish hearts were darkened.
All Commentaries on Romans 1:21 Go To Romans 1
Augustine of Hippo
AD 430
Surely that darkening of the heart was already a penalty and punishment, and by that penalty, that is by the blinding of the heart because of the abandonment by the light of wisdom, they fell into more and more serious sins.
