Who said "To know oneself is the beginning of all true knowledge."?

This quote is attributed to Wilhelm II.

To know oneself is the beginning of all true knowledge. - Wilhelm II

"To know oneself is the beginning of all true knowledge."

Wilhelm II Knowledge

Kaiser, Monarch German 1859–1941

"The fact that I am not always right is something of which I am well aware."

"We have fought this war like sissies and not like men."

"You will find that the the Americans only outwish us."

"I am the German Emperor, and I consider myself an instrument of the Lord."

"We're not just after treasure. We're preserving history."

"The mind is humanity's greatest tool."

"A tidy room reflects a tidy mind."

"You can learn a lot about a person by how they keep their space."