How wonderful that we have met with a paradox. Now we have some hope of making progress.

When searching for harmony in life one must never forget that in the drama of existence we are ourselves both actors and spectators.

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.

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.'

Every sentence I utter must be understood not as an affirmation, but as a question.

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.

An independant reality in the ordinary physical sense can neither be ascribed to the phenomenon nor to the agencies of observation.