Werner Heisenberg — "The decision to break with the tradition of classical physics was a very difficu…"

"We have to remember that what we observe is not nature in itself but nature exposed to our method of questioning."

"Can nature possibly be so absurd as it seemed to us in these atomic experiments?"

"The idea of an objective real world whose smallest parts exist objectively in the same sense as stones or trees exist, independently of whether or not we observe them... is impossible."

"One cannot be a physicist without feeling that a religious element is present in the world."

"The existing scientific concepts cover always only a very limited part of reality, and the other part which has not yet been understood is infinite."