The religious geniuses of all ages have been distinguished by this kind of religious feeling, which knows no dogma and no God conceived in man's image; so that there can be no church whose central teachings are based on it. Hence it is precisely among the heretics of every age that we find men who were filled with this highest kind of religious feeling and were in many cases regarded by their contemporaries as atheists, sometimes also as saints. Looked at in this light, men like Democritus, Francis of Assisi, and Spinoza are closely akin to one another.

Much later questions were raised whether the measurements had been accurate enough to support Einstein's theory. Their readings included the works of Henri Poincaré Ernst Mach and David Hume which influenced his scientific and philosophical outlook. Quantizing these oscillators each level will have an integer occupation number which will be the number of particles in it.

Later with the British philosopher Bertrand Russell Einstein signed the Russell–Einstein Manifesto which highlighted the danger of nuclear weapons. Einstein was in support of defending the Allied forces but largely denounced using the new discovery of nuclear fission as a weapon. Roosevelt that Germany might be developing an atomic weapon and recommended that the U.