You can't conquer a free man; the most you can do is kill him.

He never gave up his search for the Door into Summer.

Spacemen - men who work in space, pilots and jetmen and astrogators and such - are men who like a few million miles of elbow room.

I'm afraid of coaching, of writer's classes, of writer's magazines, of books on how to write. They give me centipede trouble - you know the yarn about the centipede who was asked how he managed all his feet? He tried to answer, stopped to think about it, and was never able to walk another step.

Ignorance is curable, stupid is forever.

Pain is the basic mechanism built into us by millions of years of evolution which safeguards us by warning when something threatens our survival.

Violence never settles anything should be debated by the ghosts of Hitler and Stalin, with the city fathers of Carthage as referees.