Only assholes put a nickname on their business card.

You think you can destroy the planet? What intoxicating vanity. . . . . We've been residents here for the blink of an eye. If we're gone tomorrow, the earth will not miss us.

It's better to die laughing than to live each moment in fear.

The past history of human belief is a cautionary tale. We have killed thousands of our fellow human beings because we believed they had signed a contract with the devil, and had become witches. We still kill more than a thousand people each year for witchcraft. In my view, there is only one hope for humankind to emerge from what Carl Sagan called "the demon-haunted world" of our past. That hope is science.

Personally, I don't deal much in theory. I have to deal with the facts. And on the basis of facts, I don't see much difference in the behavior of men and women.

All your life people will tell you things. And most of the time, probably ninety-five percent of the time, what they'll tell you will be wrong.

The experience of climbing Kilimanjaro affected me so powerfully that, for a long time afterward, if I caught myself saying, "I'm not a person who likes to do that activity, eat that food, listen to that music," I would automatically go out and do what I imagined I didn't like. Generally I found I was wrong about myself - I liked what I thought I wouldn't like. And even if I didn't like the particular experience, I learned I liked having new experiences.