If all insects disappeared, all life on earth would perish. If all humans disappeared, all life on earth would flourish.

My ambition was to bring to bear on medicine a chemical approach. I did that by chemical manipulation of viruses and chemical ways of thinking in biomedical research.

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.

I feel that the greatest reward for doing is the opportunity to do more.

I do what I feel impelled to do, as an artist would. Scientists function in the same way. I see all these as creative activities, as all part of the process of discovery. Perhaps that's one of the characteristics of what I call the evolvers, any subset of the population who keep things moving in a positive, creative, constructive way, revealing the truth and beauty that exists in life and in nature.

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

The most important question we must ask ourselves is, 'Are we being good ancestors?'