Philosophy starts with doubt and loves only truth.

Common sense is the measure of the possible; it is composed of experience and prevision; it is calculation applied to life.

He who asks of life nothing but the improvement of his own nature... is less liable than anyone else to miss and waste life.

A man must be able to cut a knot, for everything cannot be untied; he must know how to disengage what is essential from the detail in which it is enwrapped, for everything cannot be equally considered; in a word, he must be able to simplify his duties, his business and his life.

How true it is that our destinies are decided by nothings and that a small imprudence helped by some insignificant accident, as an acorn is fertilized by a drop of rain, may raise the trees on which perhaps we and others shall be crucified.

Man is a passion which brings a will into play, which works an intelligence.

He who is silent is forgotten; he who does not advance falls back; he who stops is overwhelmed; out distanced, crushed; he who ceases t grow becomes smaller; he who leaves off, gives up; the condition of standing still is the beginning of the end.