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

I'm not interested in age. People who tell me their age are silly. You're as old as you feel.

The more a man loves, the more he suffers. The sum of possible grief for each soul is in proportion to its degree of perfection.

[I]t is truth alone-scientific, established, proved, and rational truth-which is capable of satisfying nowadays the awakened minds of all classes. We may still say perhaps, 'faith governs the world,'-but the faith of the present is no longer in revelation or in the priest-it is in reason and in science.

To know how to suggest is the art of teaching.

Man never knows what he wants; he aspires to penetrate mysteries and as soon as he has, wants to re-establish them. Ignorance irritates him and knowledge cloys.

Common sense is calculation applied to life.