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

To make discoveries, you have to be curious about why the universe is the way it is.

Humanity has the stars in its future, and that future is too important to be lost under the burden of juvenile folly and ignorant superstition.

I want to be a human being, nothing more and nothing less. ... I don't suppose we can ever stop hating each other, but why encourage that by keeping the old labels with their ready-made history of millennial hate?

The first law of dietetics seems to be: if it tastes good, it's bad for you.

The temptation was great to muster what force we could and put up a fight. It's the easiest way out, and the most satisfactory to self-respect--but, nearly invariably, the stupidest.

If a conclusion is not poetically balanced, it cannot be scientifically true.