Courage, not cleverness; not even inspiration, is the grain of mustard that grows up to be a great tree.

A philosopher is a man who has to cure many intellectual diseases in himself before he can arrive at the notions of common sense.

A teacher who can show good, or indeed astounding results while he is teaching, is still not on that account a good teacher, for it may be that, while his pupils are under his immediate influence, he raises them to a level which is not natural to them, without developing their own capacities for work at this level, so that they immediately decline again once the teacher leaves the schoolroom.

A man will be imprisoned in a room with a door that's unlocked and opens inwards; as long as it does not occur to him to pull rather than push it.

The truth can be spoken only by someone who is already at home in it; not by someone who still lives in untruthfulness, and does no more than reach out towards it from within untruthfulness.

There is no more light in a genius than in any other honest man—but he has a particular kind of lens to concentrate this light into a burning point.

Nothing is so difficult as not deceiving oneself.

Our greatest stupidities may be very wise.

Aim at being loved without being admired.

People nowadays think that scientists exist to instruct them, poets, musicians, etc. to give them pleasure. The idea that these have something to teach them — that does not occur to them.