Whatever humans have learned had to be learned as a consequence only of trial and error experience. Humans have learned only through mistakes.

When I am working on a problem, I never think about beauty but when I have finished, if the solution is not beautiful, I know it is wrong.

Never forget that you are one of a kind. Never forget that if there weren't any need for you in all your uniqueness to be on this earth, you wouldn't be here in the first place.

I find man utterly unaware of what his wealth is or his fundamental capability is. He says time and again, "We can't afford it." For instance, we are saying now that we can't afford to do anything about pollution but after the costs of not doing something about pollution have multiplied many fold beyond what it would cost to correct it now, we will spend many fold what it would cost us now to correct it.

Dictators never invent their own opportunities.

We are called to be architects of the future, not its victims.

Relativity is inherently convergent, though convergent toward a plurality of centers of abstract truths.