“Nationalism is an infantile thing. It is the measles of mankind.”

“El nacionalismo es una enfermedad infantil. Es el sarampion de la humanidad.”

“As long as there are sovereign nations possessing great power, war is inevitable.”

“It is my view that the vegetarian manner of living, by its purely physical effect on the human temperament, would most beneficially influence the lot of mankind.”

“I believe in Spinoza's God, who reveals Himself in the lawful harmony of the world, not in a God who concerns Himself with the fate and the doings of mankind... to Rabbi Herbert Goldstein (1929)”

“Children don’t heed the life experiences of their parents, and nations ignore history. Bad lessons always have to be learned anew. ”

“The release of atomic power has changed everything except our way of thinking ... the solution to this problem lies in the heart of mankind. If only I had known, I should have become a watchmaker. (1945)”