Teaching should be such that what is offered is perceived as a valuable gift and not as hard duty. Never regard study as duty but as the enviable opportunity to learn to know the liberating influence of beauty in the realm of the spirit for your own personal joy and to the profit of the community to which your later work belongs.

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.