Our care should not be to have lived long as to have lived enough.

Nature does not reveal all her secrets at once. We imagine we are initiated in her mysteries: we are, as yet, but hanging around her outer courts.

We have lost morals, justice, honor, piety and faith, and that sense of shame which, once lost, can never be restored.

The approach of liberty makes even an old man brave.

When one is friend on himself, also is friend of everybody.

I have withdrawn not only from men, but from affairs, especially my own affairs; I am working for later generations, writing down some ideas that may be of assistance to them.

Life is divided into three periods: that which has been, that which is, that which will be. Of these the present is short, the future is doubtful, the past is certain.