A good parent gives their child roots and wings.

One of the greatest rewards for doing can be the chances it gives to do some more - even better.

Reply when questioned on the safety of the polio vaccine he developed: It is safe, and you can't get safer than safe.

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

I think of evolution as an error-making and error-correcting process, and we are constantly learning from experience.

I'm saying that we should trust our intuition. I believe that the principles of universal evolution are revealed to us through intuition. And I think that if we combine our intuition and our reason, we can respond in an evolutionary sound way to our problems.

It is said to await certainty is to await eternity.