Without a rich heart, wealth is an ugly beggar.

We write from aspiration and antagonism, as well as from experience. We paint those qualities which we do not posses.

Whenever a true theory appears, it will be its own evidence. Its test is, that it will explain all phenomena.

The intellectual life may be kept clean and healthful, if man will live the life of nature, and not import into his mind difficulties which are none of his.

Every natural power exhilarates; a true talent delights the possessor first.

When some external event raises your spirits and you think good days are preparing for you, do not believe it. It can never be so. Nothing can bring you peace but yourself.

With the past, I have nothing to do; nor with the future. I live now.