Training was one thing, reality another.

The fact that we have not yet found the slightest evidence for life - much less intelligence - beyond this Earth does not surprise or disappoint me in the least. Our technology must still be laughably primitive, we may be like jungle savages listening for the throbbing of tom-toms while the ether around them carries more words per second than they could utter in a lifetime.

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

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.

Good morning, Dr. Chandra. This is Hal. I am ready for my first lesson.

If an elderly but distinguished scientist says that something is possible, he is almost certainly right; but if he says that it is impossible, he is very probably wrong.

I'm surprised at some technological development, and the realization that any sufficiently advanced technology is indistinguishable from magic. I think the CD-ROM is the best example of that. The idea of having a whole symphony, or opera, or novel in a little piece of plastic is pretty amazing.