I think the first duty of all art, including fiction of any kind, is to entertain. That is to say, to hold interest. No matter how worthy the message of something, if it's dull, you're just not communicating.

He had seen too much of the cosmos to have any great faith in man's ability to understand it.

Colonization means potential immortality for the human genus. Man's safety on Earth was never great, and it dwindles hourly. Disarmament, even world government, will not guarantee survival in an age when population presses natural resources to the limit and when the knowledge of how to work mischief on a planetary scale is ever more widely diffused among peoples who may grow ever more desperate.

I wrote the first book, Harvest of Stars, and as I was writing it, I saw that certain implications had barely been touched on... It's perfectly obvious that two completely revolutionary things are going on, with cybernetics, and biological science.

Machines can only find what ignorant men have programmed them to find.

There are some ideas so stupid that only intellectuals can believe in them, particularly left-wing intellectuals.

I have yet to see any problem, however complicated, which, when you looked at it in the right way, did not become still more complicated.