Clever people will recognize and tolerate nothing but cleverness.

Mutual respect implies discretion and reserve even in love itself; it means preserving as much liberty as possible to those whose life we share. We must distrust our instinct of intervention, for the desire to make one's own will prevail is often disguised under the mask of solicitude.

Wisdom consists in rising superior both to madness and to common sense, and is lending oneself to the universal illusion without becoming its dupe.

It is by teaching that we teach ourselves, by relating that we observe, by affirming that we examine, by showing that we look, by writing that we think, by pumping that we draw water into the well.

Life is an apprenticeship to the constant renunciations, to the steady failure of our claims, our hopes, our powers, our liberty.

It gives liberty and breadth to thought, to learn to judge our own epoch from the point of view of universal history, history from the point of view of geological periods, geology from the point of view of astronomy.

Society lives by faith, and develops by science.