"Adapt or perish, now as ever, is nature's inexorable imperative."

"Non-violence is the policy of the vegetable kingdom"

"When I see an adult on a bicycle, I do not despair for the future of the human race."

"No passion in the world is equal to the passion to alter someone else's draft."

"Moral indignation is jealousy with a halo."

"The crisis of today is the joke of tomorrow."

"Put your shoulder to the wheel."

"Our deeds determine us, as much as we determine our deeds."

"Not that you lied to me, but that I no longer believe you, has shaken me."

"I think we agree, the past is over."

"The more I study religions the more I am convinced that man never worshipped anything but himself"

"A man, to be greatly good, must magine intensely and comprehensively; he must put himself in the place of another and in many others; the pains and pleasures of his species must become his own."