I don't think I've ever held a racket in my hand ... There's got to be somebody in the US who isn't trying to play tennis and stinking up the court.

You can prove anything you want by coldly logical reason---if you pick the proper postulates.

Experimentation is the least arrogant method of gaining knowledge. The experimenter humbly asks a question of nature.

Democracy cannot survive overpopulation.

Humanity has the stars in its future, and that future is too important to be lost under the burden of juvenile folly and ignorant superstition.

I even got a letter from a young woman in British Columbia that began as follows: 'Today I am eighteen. I am sitting at the window, looking out at the rain, and thinking how much I love you.'

Intuition is the art, peculiar to the human mind, of working out the correct answer from data that is, in itself, incomplete or even, perhaps, misleading.