All science has one aim, namely, to find a theory of nature.

Be not the slave of your own past.

The heroic soul does not sell its justice and its nobleness. It does not ask to dine nicely and to sleep warm. The essence of greatness is the perception that virtue is enough. Poverty is its ornament. It does not need plenty, and can very well abide its loss.

Intemperance is the only vulgarity.

People who wash much have a high mind about it, and talk down to those who wash little.

Do not be too timid and squeamish about your actions.

The torments of martyrdom are probably most keenly felt by the bystanders.