Men are four;
He who knows and knows not that he knows. He is asleep; wake him.
He who knows not and knows not that he knows not. He is a fool; shun him.
He who knows not and knows that he knows not. He is a child; teach him.
He who knows and knows that he knows. He is a king; follow him.
The heights by great men reached and kept
Were not attained by sudden flight,
But they, while their companions slept,
Were toiling upward in the night.