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

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

“There is no great discoveries and advances, as long as there is an unhappy child on earth. / Ne možemo govoriti o napretku čovječanstva, dok na svijetu ima nesretne djece.”

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

“Do not grow old, no matter how long you live. Never cease to stand like curious children before the Great Mystery into which we were born.”

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

“You cannot simultaneously prevent and prepare for war.”