The most superior of scientific goals is to embrace a maximum of experiment with a minimum of hypotheses.

In living through this great epoch, it is difficult to reconcile oneself to the fact that one belongs to that mad, degenerate species that boasts of its free will. How I wish that somewhere there existed an island for those who are wise and of good will. In such a place even I should be an ardent patriot!

Since I have introduced this term I had always a bad conscience. . . . I cannot help to feel it strongly and I am unable to believe that such an ugly thing should be realized in nature.

I live my daydreams in music.

The trouble with the younger generation is that they don't stay young for very long.

Intelligence and genius

Body and soul are not two different things, but only two different ways of perceiving the same thing. Similarly, physics and psychology are only different attempts to link our experiences together by way of systematic thought.