Every valuable human being must be a radical and a rebel, for what he must aim at is to make things better than they are.

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.'

Your theory is crazy, but it's not crazy enough to be true.

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.

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.

Rutherford is a man you can rely on; he comes regularly and enquires how things are going and talks about the smallest details - Rutherford is such an outstanding man and really interested in the work of all the people around him.

A person who wasn't outraged on first hearing about quantum theory didn't understand what had been said.