There is no such thing as failure, there's just giving up too soon.

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

There is a moment of conception and a moment of birth, but between them there is a long period of gestation.

The worst tragedy that could have befallen me was my success. I knew right away that I was through - cast out.

A good parent gives their child roots and wings.

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

When things get bad enough, then something happens to correct the course. And it's for that reason that I speak about evolution as an error-making and an error-correcting process. And if we can be ever so much better - ever so much slightly better - at error correcting than at error making, then we'll make it.