"Racism, pollution and the rest of it are themselves very close to extinction."

"I think I am a verb."

"Nature is trying very hard to make us succeed, but nature does not depend on us. We are not the only experiment."

"Humanity is acquiring all the right technology for all the wrong reasons."

"Dare to be naive."

"Now there is one outstandingly important fact regarding Spaceship Earth, and that is that no instruction book came with it."

"Every gun that is made, every warship launched, every rocket fired in the final analysis, is a theft from those who hunger and are not fed, who are cold and not clothed."

"Open your mouth and purse cautiously; and your stock of wealth and reputation shall, at least in repute, be great."

"A thing moderately good is not so good as it ought to be. Moderation in temper is always a virtue, but moderation in principle is always a vice."

"The most important trip you may take in life is meeting people halfway."

"Were there but one virtuous man in the world, he would hold up his head with confidence and honor; he would shame the world, and not the world him."

"It is good to have an end to journey towards; but it is the journey that matters in the end."