Our friends show us what we can do; our enemies teach us what we must do.

To me the external existence of my soul is proved from my idea of activity. If I work incessantly until my death, nature will give me another form of existence when the present can no longer sustain my spirit.

One man's word is no man's word; we should quietly hear both sides.

I am fully convinced that the soul is indestructible, and its activity will continue through eternity.

Treat people the way they are and they will stay that way. Treat people the way they can become and they will become that way.

On top of the world, or in the depths of despair.

Mysterious in the light of day, nature retains her veil, despite our clamours: That which she does not willingly display cannot be wrenched from her with levers, screws and hammers.