541.
The fool who knows his foolishness is wise so far, at least; but a fool who thinks himself wise, he is called a fool indeed.
Dhammapada.
542.
He who mixes with unclean things becomes unclean himself; he whose associations are pure becomes purer each day.
Talmud.
543.
Heaven’s gate is narrow and minute,*
It cannot be perceived by foolish men,
Blinded by vain illusions of the world.