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

When you inoculate children with a polio vaccine, you don't sleep well for two or three months.

Our greatest responsibility is to be good ancestors.

I speak about universal evolution and teleological evolution, because I think the process of evolution reflects the wisdom of nature. I see the need for wisdom to become operative. We need to try to put all of these things together in what I call an evolutionary philosophy of our time.

Eventually we'll realize that if we destroy the ecosystem, we destroy ourselves.

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

It is courage based on confidence, not daring, and it is confidence based on experience.