The true teacher knocks down the idol that the student makes of him.
Talent is like a marksman who hits a target which others cannot reach; genius is like a marksman who hits a target which others cannot see.
For man, the unexamined life is not worth living.
The fool who persists in his folly will become wise.
It is impossible for a man to learn what he thinks he already knows.
Wisdom comes by disillusionment.