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

Once, when a religionist denounced me in unmeasured terms, I sent him a card saying, "I am sure you believe that I will go to hell when I die, and that once there I will suffer all the pains and tortures the sadistic ingenuity of your deity can devise and that this torture will continue forever. Isn't that enough for you? Do you have to call me bad names in addition?"

Nothing has to be true, but everything has to sound true.

I don't subscribe to the thesis, 'Let the buyer beware,' I prefer the disregarded one that goes, 'Let the seller be honest.'

To test a perfect theory with imperfect instruments did not impress the Greek philosophers as a valid way to gain knowledge.

The further a device is removed from human control, the more authentically mechanical it seems, and the whole trend in technology has been to devise machines that are less and less under direct human control and more and more under their own apparent will.

Intelligence is a valuable thing, but it is not usually the key to survival. Sheer fecundity ... usually counts. The intelligent gorilla doesn't do as well as the less intelligent but more-fecund rat, which doesn't do as well as the still-less-intelligent but still-more-fecund cockroach, which doesn't do as well as the minimally-intelligent but maximally-fecund bacterium.