I believe any malevolent supercivilisation would have rapidly self-destructed as we may be in the process of doing ourselves. If we do have contact, physical contact with aliens, I think it will be benign.

Reading computer manuals without the hardware is as frustrating as reading sex manuals without the software.

. . . the newspapers of Utopia, he had long ago decided, would be terribly dull.

I have great faith in optimism as a guiding principle, if only because it offers us the opportunity of creating a self-fulfilling prophecy.

I'm sure we would not have had men on the Moon if it had not been for Wells and Verne and the people who write about this and made people think about it. I'm rather proud of the fact that I know several astronauts who became astronauts through reading my books.

When one has to ask, "Am I really in love?" the answer is always "No".

The success of a science fiction writer is if he can write a good read.