“Without the dreamers who write science fiction and other imaginary material we'd still be sitting in caves ... if we weren't already extinct.”

“Most science fiction seemed to be written for people who already liked science fiction; I wanted to write stories for anyone, anywhere, living at any time in the history of the world.”

“If all the people who were called "crazy" started acting "normal", we'd probably still be living in caves.”

“Religion without science is superstition. Science without religion is materialism.”

“As often I have been a science fiction writer writing science fiction for the community of science fiction readers, I am also, for good or ill, an American writing American literature to an American audience. Most fundamentally, though, I am a human being writing human literature to a human audience.”

“If there hadn't been women we'd still be squatting in a cave eating raw meat, because we made civilization in order to impress our girlfriends.”