Civilization is the art of creating useless needs.

God is the mysterious veil under which we hide our ignorance of the cause.

Truth is different from error in two respects: it is a little harder to prove and more difficult to admit.

The altruism of foresters can serve as a motto for humanity in general: "We reap what we have not sown. We sow what we do not reap."

Civilization is the art of creating useless needs.

What are we doing down here? We prepare the blossoms of tomorrow. We all manure future humanity.

Pour réussir dans la science, il faut douter; pour réussir dans la vie, il faut être sûr. To succeed in science, one must doubt; to succeed in life, one must be sure.