There is a special sadness in achievement, in the knowledge that a long-desired goal has been attained at last, and that life must now be shaped toward new ends.

In all the universe there is nothing more precious than mind.

Some things have eternal value, and compassion is one of them. I hope we never lose that. Compassion for humans as well as animals.

The time was fast approaching when Earth, like all mothers, must say farewell to her children.

Nowhere in space will we rest our eyes upon the familiar shapes of trees and plants, or any of the animals that share our world. Whatsoever life we meet will be as strange and alien as the nightmare creatures of the ocean abyss, or of the insect empire whose horrors are normally hidden from us by their microscopic scale.

The best measure of a man's honesty isn't his income tax return. It's the zero adjust on his bathroom scale.

The phenomenon of UFO doesn't say anything about the presence of intelligence in space. It just shows how rare it is here on the earth.