Professing themselves to be wise - This was the common boast of the philosophers of antiquity. The very word by which they chose to be called, “philosophers,” means literally “lovers of wisdom.” That it was their boast that they were wise, is well known; compare Romans 1:14; 1 Corinthians 1:19, 1Co 1:20, 1 Corinthians 1:22; 1 Corinthians 3:19; 2 Corinthians 11:19.
They became fools - Compare Jeremiah 8:8-9. They became really foolish in their opinions and conduct. There is something particularly pungent and cutting in this remark, and as true as it is pungent. In what way they evinced their folly, Paul proceeds immediately to state. Sinners of all kinds are frequently spoken of as fools in the Scriptures. In the sense in which it is thus used, the word is applied to them as void of understanding or moral sense; as idolaters, and as wicked; Psalms 14:1; Proverbs 26:4; Proverbs 1:17, Proverbs 1:22; Proverbs 14:8-9. The senses in which this word here is applied to the pagan are,
- That their speculations and doctrines were senseless; and,
- That their conduct was corrupt.