It is impossible, I think, that all the symbols we see in natural landscapes are there only because we see them. No one hesitates to brand as mad the solipsists who truly believe that the world exists only because they observe it and that buildings, mountains, and even ourselves (to whom they have spoken only a moment before) all vanish when they turn their heads. Is it not equally mad to believe that the meaning of the same objects vanishes in the same way?
