I’m sure the universe is full of intelligent life. It’s just been too intelligent to come here.

I don’t believe in astrology; I’m a Sagittarius and we’re skeptical.

No pessimist ever discovered the secrets of the stars, or sailed to an uncharted land, or opened a new heaven to the human spirit.

The only way of finding the limits of the possible is by going beyond them into the impossible.

We cannot predict the new forces, powers, and discoveries that will be disclosed to us when we reach the other planets and set up new laboratories in space. They are as much beyond our vision today as fire or electricity would be beyond the imagination of a fish.

As our own species is in the process of proving, one cannot have superior science and inferior morals. The combination is unstable and self destroying.

Politicians should read science fiction, not westerns and detective stories.

Science can destroy religion by ignoring it as well as by disproving its tenets. No one ever demonstrated, so far as I am aware, the non existence of Zeus or Thor but they have few followers now.

Human judges can show mercy. But against the laws of nature, there is no appeal.