The heart of man does not tolerate an absence of the excellent and supreme.

Thought is not a gift to man but a laborious, precarious and volatile acquisition.

Stupefaction, when it persists, becomes stupidity.

We do not live to think, but, on the contrary, we think in order that we may succeed in surviving.

When you are fed up with the troublesome present, you take your gun, whistle for your dog, go out to the mountain, and, without further ado, give yourself the pleasure during a few hours or a few days of being "Paleolithic."

With morality we correct the mistakes of our instincts, and with love we correct the mistakes of our morals.

Life is an operation which is done in a forward direction. One lives toward the future, because to live consists inexorably in doing, in each individual life making itself.