Sometimes the child in one behaves a certain way and the rest of oneself follows behind, slowly shaking its head.

You must come to Copenhagen to work with us. We like people who can actually perform thought experiments!

If an idea does not appear bizarre, there is no hope for it.

In our description of nature the purpose is not to disclose the real essence of the phenomena but only to track down, so far as it is possible, relations between the manifold aspects of our experience.

A physicist visits a colleague and notices a horseshoe hanging on the wall above the entrance. 'Do you really believe that a horseshoe brings luck?' he asks. 'No,' replies the colleague, 'but I've been told that it works even if you don't believe in it.'

Of course I don't believe in it [pointing to horseshoe on his office wall]. But I understand that it brings you luck whether you believe in it or not.

You can recognize a small truth because its opposite is a falsehood. The opposite of a great truth is another truth.