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.'

Theories are not so much wrong as incomplete

John Dalton's records, carefully preserved for a century, were destroyed during the World War II bombing of Manchester. It is not only the living who are killed in war.

Intelligence is an extremely subtle concept. It's a kind of understanding that flourishes if it's combined with a good memory, but exists anyway even in the absence of good memory. It's the ability to draw consequences from causes, to make correct inferences, to foresee what might be the result, to work out logical problems, to be reasonable, rational, to have the ability to understand the solution from perhaps insufficient information. You know when a person is intelligent, but you can be easily fooled if you are not yourself intelligent.

And in man is a three-pound brain which, as far as we know, is the most complex and orderly arrangement of matter in the universe.

Why continue? Because we must. Because we have the call. Because it is nobler to fight for rationality without winning than to give up in the face of continued defeats. Because whatever true progress humanity makes is through the rationality of the occasional individual and because any one individual we may win for the cause may do more for humanity than a hundred thousand who hug their superstitions to their breast.

It's just science fiction so it's allowed to be silly, and childish, and stupid. It's just science fiction, so it doesn't have to make sense. It's just science fiction, so you must ask nothing more of it than loud noises and flashing lights.