Only a few know, how much one must know to know how little one knows.

Thirty-six years old and he knows less than when he started. With the difference that now he knows how little he'll always know.

He who knows only his own side of the case knows little of that.

The person who knows only his side of the argument knows little of that.

One knows so little. When one knows more it is too late.

He who thinks he knows, doesn't know. He who knows that he doesn't know, knows.

is necessarily limited by his lack of knowledge of the circumstances

The most educated person in the world now has to admit — I shall not say confess — that he or she knows less and less but at least knows less and less about more and more.

I am likely to be wiser than he to this small, extent, that I do not think I know what I do not know.

He who knows not and knows not that he knows not is a fool. Shun him. He who knows not and knows that he knows not is a child. Teach him. He who knows and knows not that he knows is asleep. Wake him. He who knows and knows that he knows is a wise man. Follow him.

Only one who has learned much can fully appreciate his ignorance.

We know accurately only when we know little; doubt grows with knowledge.

The wisest man is generally he who thinks himself the least so.

He who knows all the answers has not been asked all the questions.