Life is an error-making and an error-correcting process.

I have had dreams and I have had nightmares, but I have conquered my nightmares because of my dreams.

As a child I was not interested in science. I was merely interested in things human, the human side of nature, if you like, and I continue to be interested in that. That's what motivates me.

Risks, I like to say, always pay off. You learn what to do, or what not to do.

My job is to help people see what I see. If it's of value, fine. And, if it's not of value, then at least I've done what I can do.

If all the insects were to disappear from the earth, within 50 years all life on earth would end. If all human beings disappeared from the earth, within 50 years all forms of life would flourish.

When I worked on the polio vaccine, I had a theory. I guided each [experiment] by imagining myself in the phenomenon in which I was interested. The intuitive realm . . . the realm of the imagination guides my thinking.