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

Shuttling back and forth in the equatorial plane where the brilliant stars of Io, Europa, Ganymede, and Callisto - worlds that elsewhere would have counted as planets in their own right, but which here were merely satellites of a giant master.

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 nonexistence of Zeus or Thor, but they have few followers now.

He did not know that the Old One was his father, for such a relationship was utterly beyond his understanding, but as he looked at the emaciated body he felt a dim disquiet that was the ancestor of sadness.

Any sufficiently advanced technology is indistinguishable from magic.

How inappropriate to call this planet "Earth," when it is clearly "Ocean.

Magic's just science that we don't understand yet.

When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.

In this single galaxy of ours there are eighty-seven thousand million suns. [...] In challenging it, you would be like ants attempting to label and classify all the grains of sand in all the deserts of the world. [...] It is a bitter thought, but you must face it. The planets you may one day possess. But the stars are not for man.