نحن في موقف شبيه بموقف متسلّق الجبال الذي يتجوّل في فضاءات مجهولة، ولا يدري أبدًا هل خلف القمة التي يراها أمامه، والتي يحاول بلوغها، قمّةٌ أخرى أبعد وأعلى.

“We are in a position similar to that of a mountaineer who is wandering over uncharted spaces, and never knows whether behind the peak which he sees in front of him and which he tries to scale there may not be another peak still beyond and higher up.”Max Planck — The new science: 3 complete works: Where is science going? The universe in the light of modern physics; The philosophy of physics (1959)