[T]he habit of scientific analysis ... exhausts the material offered to it.
Philosophy means the complete liberty of the mind.
To be misunderstood even by those whom one loves is the cross and bitterness of life. It is the secret of that sad and melancholy smile on the lips of great men which so few understand.
Common sense is calculation applied to life.
The laws of animality govern almost the whole of history.
The only substance properly so called is the soul.