Wisdom lies in understanding our limitations.

The cosmos is full beyond measure of elegant truths; of exquisite interrelationships; of the awesome machinery of nature.

Man is a transitional animal. He is not the climax of creation

The difference between physics and metaphysics is not that the practitioners of one are smarter than the practitioners of the other. The difference is that the metaphysicist has no laboratory.

The Apollo pictures of the whole Earth conveyed to multitudes something well known to astronomers: On the scale of the worlds - to say nothing of stars or galaxies - humans are inconsequential, a thin film of life on an obscure and solitary lump of rock and metal

The brain is like a muscle. When it is in use we feel very good. Understanding is joyous.

Ours is the first generation that has grown up with science-fiction ideas.