“Something deeply hidden had to be behind things.”

“A knowledge of the existence of something we cannot penetrate, of the manifestations of the profoundest reason and the most radiant beauty - it is this knowledge and this emotion that constitute the truly religious attitude; in this sense, and in this alone, I am a deeply religious man.”

“Everything that the human race has done and thought is concerned with the satisfaction of deeply felt needs and the assuagement of pain. One has to keep this constantly in mind if one wishes to understand spiritual movements and their development. Feeling and longing are the motive force behind all human endeavor and human creation, in however exalted a guise the latter may present themselves to us.”

“That which is impenetrable to us really exists. Behind the secrets of nature remains something subtle, intangible, and inexplicable. Veneration for this force beyond anything that we can comprehend is my religion.”

“To sense that behind anything that can be experienced there is a something that our mind cannot grasp and whose beauty and sublimity reaches us only indirectly and as a feeble reflection, this is religiousness. In this sense I am religious.”

“I am a deeply religious nonbeliever. This is a somewhat new kind of religion.”

“Try and penetrate with our limited means the secrets of nature and you will find that, behind all the descernible laws and connections, there remains something subtle, intangible and inexplicable. Veneration for this force beyond anything that we can comprehend is my religion. To that extent I am, in fact, religious.”