A fanatic is a man who, when he's lost sight of his purpose, redoubles his effort.

Give fear no hold on you. Keep sinews loose and senses open, ready at every instant to flow with the rush of action.

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

A fanatic is a man who, when he's lost sight of his purpose, redoubles his effort.

What five books would I like to be remembered for? Well... Tau Zero, I like that one especially. It was somewhat of a tour de force, and I think it got across what I was trying for.

So much American science fiction is parochial - not as true now as it was years ago, but the assumption is one culture in the future, more or less like ours, and with the same ideals, the same notions of how to do things, just bigger and flashier technology. Well, you know darn well it doesn't work that way.

At each stage...entirely new laws, concepts and generalizations are necessary, requiring inspiration and creativity to just as great a degree as in the previous one.