"The weight of the atom is not the only criterion; there are other considerations."

"Why do they [Americans] quarrel, why do they hate Negroes, Indians, even Germans, why do they not have science and poetry commensurate with themselves, why are there so many frauds and so much nonsens…"

"In science we must all submit not to what seems to us attractive from one point of view or another, but to what represents an agreement between theory and experiment."

"Without knowledge, without work, there is no hope for humanity."

"I saw in a dream a table where all the elements fell into place as required. Awakening, I immediately wrote it down on a piece of paper."