If I didn't exist, I would have invented myself.

A man who grows that much hair,' critics were fond of saying, 'must have a lot to hide.

The numbers of distinct human societies or nations, when our race is twice its present age, may be far greater than the total number of all the men who have ever lived up to the present time.

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.

I will not be afraid because I understand ... And understanding is happiness.

That's one of those meaningless and unanswerable questions the mind keeps returning to endlessly, like the tongue exploring a broken tooth.

Perhaps no other year before or since 1984 has been awaited with such eager anticipation.