The difference between faith and superstition is that the first uses reason to go as far as it can, and then makes the jump; the second shuns reason entirely — which is why superstition is not the ally, but the enemy, of true religion.

A cynic is not merely one who reads bitter lessons from the past, his is also one who is permanently disappointed in the future.

The real danger is not that computers will begin to think like men, but that men will begin to think like computers.

Our dilemma is that we hate change and love it at the same time; what we really want is for things to remain the same but get better.

The paradox of friendship is that it is both the strongest thing in the world and the most fragile. Wild horses cannot separate friends, but whining words can. A man will lay down his life for his friend but will not sacrifice his eardrums.

Nobody can be so amusingly arrogant as a young man who has just discovered an old idea and thinks it is his own.

All our efforts to attain immortality-by statesmanship, by conquest, by science or the arts-are equally vain in the long run, because the long run is longer than any of us can imagine.