From the Wiki: Schrödinger had a deep interest in philosophy, and was influenced by the works of Arthur Schopenhauer and Baruch Spinoza. In his 1956 lecture "Mind and Matter", he said that "The world extended in space and time is but our representation."[66] This is a repetition of the first words of Schopenhauer's main work. Schopenhauer's works also introduced him to Indian philosophy, more specifically to the Upanishads and Advaita Vedanta’s interpretation. He once took on a particular line of thought: "If the world is indeed created by our act of observation, there should be billions of such worlds, one for each of us. How come your world and my world are the same? If something happens in my world, does it happen in your world, too? What causes all these worlds to synchronize with each other?".