I consider myself to be a very fortunate person and to have led a very fortunate life.

It's the wanting to know that makes us matter.

I'm the kind of person who embarks on an endless leapfrog down the great moral issues. I put a position, rebut it, refute the rebuttal and rebut the refutation. Endlessly.

If an idea's worth having once, it's worth having twice.

If you took away everything in the world that had to be invented, there'd be nothing left except a lot of people getting rained on.

From principles is derived probability, but truth or certainty is obtained only from facts.

Well, we'll know better next time.