If [quantum theory] is correct, it signifies the end of physics as a science.

It is every man's obligation to put back into the world at least the equivalent of what he takes out of it.

The only thing that you absolutely have to know, is the location of the library.

Learn from yesterday, live for today.

Nationalism, on my opinion, is nothing more than an idealistic rationalization for militarism and aggression.

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.

It is really a puzzle what drives one to take one's work so devilishly seriously.