“You cannot simultaneously prevent and prepare for war.”

“We must be prepared to make the same heroic sacrifices for the cause of peace that we make ungrudgingly for the cause of war.”

“Life is a preparation for the future; and the best preparation for the future is to live as if there were none.”

“I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones.”

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

“So long as there are men, there will be wars.”

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