A civilization is built on what is required of men, not on that which is provided for them.

One can be a brother only in something. Where there is no tie that binds men, men are not united but merely lined up.

Only the unknown frightens men. But once a man has faced the unknown, that terror becomes the known.

We say nothing essential about the cathedral when we speak of its stones. We say nothing essential about Man when we seek to define him by the qualities of men.

The machine does not isolate man from the great problems of nature but plunges him more deeply into them.