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.'
Niels BohrTruth is something that we can attempt to doubt, and then perhaps, after much exertion, discover that part of the doubt is not justified.
Niels BohrA person who wasn't outraged on first hearing about quantum theory didn't understand what had been said.
Niels BohrWe depend on our words... Our task is to communicate experience and ideas to others. We must strive continually to extend the scope of our description, but in such a way that our messages do not thereby lose their objective or unambiguous character... We are suspended in language in such a way that we cannot say what is up and what is down. The word "reality" is also a word, a word which we must learn to use correctly.
Niels Bohr