All of a sudden, space isn't friendly. All of a sudden, it's a place where people can die. . . . Many more people are going to die. But we can't explore space if the requirement is that there be no casualties; we can't do anything if the requirement is that there be no casualties.

Although the time of death is approaching me, I am not afraid of dying and going to Hell or (what would be considerably worse) going to the popularized version of Heaven. I expect death to be nothingness and, for removing me from all possible fears of death, I am thankful to atheism.

... you just can't differentiate between a robot and the very best of humans.

A subtle thought that is in error may yet give rise to fruitful inquiry that can establish truths of great value.

Scientists derive satisfaction from figuring out the puzzle. It's about the quest, not the grail.

It is not so much that I have confidence in scientists being right, but that I have so much in nonscientists being wrong.

I type 90 words per minute on the typewriter; I type 100 words per minute on the word processor. But, of course, I don't keep that up indefinitely - every once in a while I do have to think a few seconds.