Of what significance is one's existence, one is basically unaware. What does a fish know about the water in which he swims all his life? The bitter and the sweet come from outside. The hard from within, from one's own efforts. For the most part I do what my own nature drives me to do. It is embarrassing to earn such respect and love for it.

They come into being not through demonstration but through revelation, through the medium of powerful personalities.

Great spirits have always found violent opposition from mediocre minds. The latter cannot understand it when a man does not thoughtlessly submit to hereditary prejudices but honestly and courageously uses his intelligence.

There is possibility in every difficulty.

We are in the position of a little child entering a huge library, whose walls are covered to the ceiling with books in many different languages. The child knows that someone must have written those books. It does not know who or how. It does not understand the the languages in which they are written. The child notes a definite plan in the arrangement of the books, a mysterious order, which it does not comprehend but only dimly suspects.

A happy man is too satisfied with the present to dwell too much on the future.

A theory can be proved by experiment; but no path leads from experiment to the birth of a theory.