“There is nothing divine about morality, it is a purely human affair.”

“Although I have been prevented by outward circumstances from observing a strictly vegetarian diet, I have long been an adherent to the cause in principle. Besides agreeing with the aims of vegetarianism for aesthetic and moral reasons, it is my view that a vegetarian manner of living by its purely physical effect on the human temperament would most beneficially influence the lot of mankind.”

“The most important human endeavor is the striving for morality in our actions. Our inner balance and even our very existence depend on it. Only morality in our actions can give beauty and dignity to life.”

“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.”

“Two things are infinite: the universe and human stupidity; and I'm not sure about the universe.”

“You are right in speaking of the moral foundations of science, but you cannot turn around and speak of the scientific foundations of morality.”

“It is the duty of every citizen according to his best capacities to give validity to his convictions in political affairs.”