Man's mind is his basic tool of survival. Life is given to him, survival is not. His body is given to him, its sustenance is not. His mind is given to him, its content is not. To remain alive, he must act, and before he can act he must know the nature and purpose of his action. He cannot obtain his food without a knowledge of food and of the way to obtain it. He cannot dig a ditch-or build a cyclotron-without a knowledge of his aim and of the means to achieve it. To remain alive, he must think

Civilization is the progress toward a society of privacy.

It's true that there's no such thing as free will. We can't help what we are or what we do. It's not our fault. Nobody's to blame for anything. It's all in your background ... and your glands. If you're good, that's no achievement of yours - you were lucky in your glands. If you're rotten, nobody should punish you - you were unlucky, that's all.

The moral is the chosen, not the forced; the understood, not the obeyed. The moral is the rational, and reason accepts no commandments.

To demand 'sense' is the hallmark of nonsense. Nature does not make sense. Nothing makes sense.

The entire history of science is a progression of exploded fallacies.

You'll come back, because yours is an error of knowledge, not a moral failure, not an act of surrender to evil, but only the last act of being victim to your own virtue. We'll wait for you and when you come back, you will have discovered that there need never be any conflict among your desires, nor so tragic a clash of values as the one you've borne so well.