The finest emotion of which we are capable is the mystic emotion.

Insofar as mathematics is true, it does not describe the real world. Insofar as it describes the real world, it is not true.

Whether or not you can observe a thing depends upon the theory you use. It is the theory which decides what can be observed.

Conviction is a good motive, but a bad judge.

The height of stupidity is most clearly demonstrated by the individual who ridicules something he knows nothing about.

Science will stagnate if it is made to serve practical goals.

I do not share the crusading spirit of the professional atheist whose fervor is mostly due to a painful act of liberation from the fetters of religious indoctrination received in youth. I prefer an attitude of humility corresponding to the weakness of our intellectual understanding of nature and of our own being.