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.

No one can possibly have lived through the Great Depression without being scarred by it. No amount of experience since the depression can convince someone who has lived through it that the world is safe economically.

When asked for advice by beginners. Know your ending, I say, or the river of your story may finally sink into the desert sands and never reach the sea.

I, on the other hand, am a finished product. I absorb electrical energy directly and utilize it with an almost one hundred percent efficiency. I am composed of strong metal, am continuously conscious, and can stand extremes of environment easily. These are facts which, with the self-evident proposition that no being can create another being superior to itself, smashes your silly hypothesis to nothing.

The facts, gentlemen, and nothing but the facts, for careful eyes are narrowly watching.

Before another century is done it will be hard for people to imagine a time when humanity was confined to one world, and it will seem to them incredible that there was ever anybody who doubted the value of space and wanted to turn his or her back on the Universe.

Intelligence is a valuable thing, but it is not usually the key to survival. Sheer fecundity ... usually counts. The intelligent gorilla doesn't do as well as the less intelligent but more-fecund rat, which doesn't do as well as the still-less-intelligent but still-more-fecund cockroach, which doesn't do as well as the minimally-intelligent but maximally-fecund bacterium.