Romans 1:20-22 says: For the invisible things of Him from the creation of the world are clearly seen, being understood by the things that are made, even His eternal power and Godhead; so that they are without excuse; Because that, when they knew God, they glorified Him not as God, neither were thankful; but became vain in their imaginations, and their foolish heart was darkened. Professing themselves to be wise, they became fools.
God gave man the ability to look around himself and reasonably conclude some basic things about creation and a creator. But man, in his vanity, elevates this reasoning ability to Godlike status, thinking he can know all that is known. In doing so, he becomes a fool.
Socrates reached the same conclusion as the writer of the Proverb "Be not wise in your own eyes"