Man is not the most majestic of the creatures; long before the mammals even, the dinosaurs were far more splendid. But he has what no other animal possesses: a jigsaw of faculties, which alone, over three thousand million years of life, made him creative. Every animal leaves traces of what he was. Man alone leaves traces of what he created.

We have to understand that the world can only be grasped by action, not by contemplation. The hand is more important than the eye ... The hand is the cutting edge of the mind.

The great poem and the deep theorem are new to every reader, and yet are his own experiences, because he himself recreates them.

There is no absolute knowledge. And those who claim it, whether they are scientists or dogmatists, open the door to tragedy.

The hand is the cutting edge of the mind.

The progress of science is the discovery at each step of a new order which gives unity to what had seemed unlike.

The problem of values arises only when men try to fit together their need to be social animals with their need to be free men. There is no problem, and there are no values, until men want to do both. If an anarchist wants only freedom, whatever the cost, he will prefer the jungle of man at war with man. And if a tyrant wants only social order, he will create the totalitarian state.