I believe that the existence of the classical "path" can be pregnantly formulated as follows: The "path" comes into existence only when we observe it.
Werner HeisenbergIt was about three o'clock at night when the final result of the calculation [which gave birth to quantum mechanics] lay before me ... At first I was deeply shaken ... I was so excited that I could not think of sleep. So I left the house ... and awaited the sunrise on top of a rock.
Werner Heisenberg[T]he atoms or elementary particles themselves are not real; they form a world of potentialities or possibilities rather than one of things or facts.
Werner HeisenbergWhether we electrons, light quanta, benzol molecules, or stones, we shall always come up against these two characteristics, the corpuscular and the undular.
Werner Heisenberg