I have never written a book that didn't teach me far more than it taught my reader.

Do not forget that a traitor within our ranks, known to us, can do more harm to the enemy than a loyal man can do good to us.

I am an atheist, out and out. It took me a long time to say it. I've been an atheist for years and years, but somehow I felt it was intellectually unrespectable to say that one is an atheist, because it assumed knowledge that one didn't have. Somehow it was better to say one was a humanist or agnostic. I don't have the evidence to prove that God doesn't exist, but I so strongly suspect that he doesn't that I don't want to waste my time.

I have never written a book that didn't teach me far more than it taught my reader.

Science can be introduced to children well or poorly. If poorly, children can be turned away from science; they can develop a lifelong antipathy; they will be in a far worse condition than if they had never been introduced to science at all.

[Social] science fiction is that branch of literature which is concerned with the impact of scientific advance on human beings.

Why is it, I wonder, that anyone who displays superior athletic ability is an object of admiration to his classmates, while one who displays superior mental ability is an object of hatred?