The more closely you look at one thing, the less closely can you see something else.

The solution of the difficulty is that the two mental pictures which experiment lead us to form - the one of the particles, the other of the waves - are both incomplete and have only the validity of analogies which are accurate only in limiting cases.

The 'path' comes into existence only when we observe it.

The reality we can put into words is never reality itself.

The problems of language here are really serious. We wish to speak in some way about the structure of the atoms. But we cannot speak about atoms in ordinary language.

What we observe is not nature itself, but nature exposed to our method of questioning.

Whether we electrons, light quanta, benzol molecules, or stones, we shall always come up against these two characteristics, the corpuscular and the undular.