"I have an odd theory on happiness, and it bothers people. My general theory is that happiness is a reward for an animal doing what it should be doing. So if a horse runs, it feels happy. Or if you are too thin, you can't be happy, because evolution wants you to be tense and anxious, trying to wake up in the morning looking for food."

"My wife and I have a schizophrenic son. We didn't want to accept this for 30 years, so we put him under great pressure when we shouldn't have. He just wanted to be looked after, and we didn't respect that. We tried to make him independent."

"As a child, I lived with being punier than other boys in class. The only consolation was my parents' empathy - they encouraged constant trips to the local drugstore for chocolate milk shakes to fatten me up. The shakes made me happy, but still, all through grammar school, other kids shoved me around."

"It is no coincidence that so many religious beliefs date back to times when no science could possibly have accounted satisfactorily for many of the natural phenomena inspiring scripture and myths."

"My heroes were never scientists. They were Graham Greene and Christopher Isherwood, you know, good writers."

"The luckiest thing that ever happened to me was that my father didn't believe in God, and so he had no hang-ups about souls."

"I want to see cancer cured in my lifetime. It might be."

"Spotting a rare bird is never worth the bite of a cur. Once bitten by a German shepherd, I knew that I preferred cats, even if they are bird-killers. Life is long enough for more than one chance at a rare bird."

"I am happy that I can aid those admirable men, both living and dead, who by their pens or their tongues have aided the great cause of human liberty and universal happiness."

"It's necessary to be slightly underemployed if you are to do something significant."

"The ever quickening advances of science made possible by the success of the Human Genome Project will also soon let us see the essences of mental disease. Only after we understand them at the genetic level can we rationally seek out appropriate therapies for such illnesses as schizophrenia and bipolar disease."

"At lunch Francis winged into the Eagle to tell everyone within hearing distance that we had found the secret of life."

"I have never seen Francis Crick in a modest mood. Perhaps in other company he is that way, but I have never had reason so to judge him."

"[As a young man ] I came to the conclusion that the church was just a bunch of fascists that supported Franco. I stopped going on Sunday mornings and watched the birds with my father instead."

"My parents made it clear that I should never display even the slightest disrespect to individuals who had the power to let me skip a half grade or move into more challenging classes. While it was all right for me to know more about a topic than my sixth-grade teacher had ever learned, questioning her facts could only lead to trouble."

"We're not all equal, it's simply not true. That isn't science."

"People say we are playing God. My answer is: If we don't play God, who will?"

"Today, the theory of evolution is an accepted fact for everyone but a fundamentalist minority, whose objections are based not on reasoning but on doctrinaire adherence to religious principles."

"Although science interests me just because of its efforts to escape from anthropomorphic knowledge, I am nonetheless convinced that our imagination cannot be anything but anthropomorphic."

"True science investigates and brings to human perception such truths and such knowledge as the people of a given time and society consider most important. Art transmits these truths from the region of perception."

"I worry about scientists discovering that lettuce has been fattening all along. . . ."

"This process of self-discovery is scientific and the invariable rule of science has to be applied - experiment and observe."

"Science rests on reason and experiment, and can meet an opponent with calmness; but a belief is always sensitive."

"To be humane, we must ever be ready to pronounce that wise, ingenious and modest statement 'I do not know'."