Knowing what
Thou knowest not
Is in a sense
Omniscience.

— Piet Hein,
poet and scientist (1905-1996)

He who knows does not speak.
He who speaks does not know.

–Lao-tzu, The Way of Lao-tzu
Chinese philosopher (604 BC – 531 BC)

“He who thinks he knows does not know; he who knows he does not know knows.”

— Often Attributed to Joseph Campbell