“A man who knows how little he knows is well, a man who knows how much he knows is sick.”

“Every man who has thought, knows not only how little he knows, but how little every other human being knows, and how ignorant, after all, the world must be.”

Robert G. Ingersoll (1833–1899) Union United States Army officer

“He who knows best knows how little he knows.”

Thomas Jefferson (1743–1826) 3rd President of the United States of America

“You are a man now, and to be un hombre, a man must not only know right from wrong, he must also know who he is and who he isn’t. Because if a man doesn’t know who he is and who he isn’t, then no matter how much he knows about right and wrong, he will always be like a fish out of water.”

Victor Villaseñor (1940) American writer

“The man who is a pessimist before 48 knows too much; if he is an optimist after it he knows too little.”

Mark Twain (1835–1910) American author and humorist

“The strong man is he who knows how and is able to become and be himself; the magnanimous man is he who, being strong, knows how and is able to issue forth from himself, as from a fortress, to guide, protect, encourage, and save others.”

John Lancaster Spalding (1840–1916) Catholic bishop

“He Who Knows And Knows That He Knows Is A Wise Man - Follow Him;
He Who Knows Not And Knows Not That He Knows Not Is A Fool - Shun Him”

Confucius (-551–-479 BC) Chinese teacher, editor, politician, and philosopher

“That man lives badly who does not know how to die well.”

Seneca the Younger (-4–65 BC) Roman Stoic philosopher, statesman, and dramatist

“The white man knows how to make everything, but he does not know how to distribute it.”

Sitting Bull (1831–1890) Hunkpapa Lakota medicine man and holy man

“Ah well—the boss didn’t have to know how to run the business. He only needed to know how to run the people who knew.”

David Gerrold book When HARLIE Was One