There are two sorts of truth: trivialities, where opposites are clearly absurd, and profound truths, recognised by the fact that the opposite is also a profound truth

We 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.

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

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

No paradox, no progress.

Anybody who is not shocked by this subject has failed to understand it. [of quantum mechanics]

When we measure something we are forcing an undetermined, undefined world to assume an experimental value. We are not measuring the world, we are creating it.