Ingratitude is the essence of vileness.

Seek not the favor of the multitude; it is seldom got by honest and lawful means. But seek the testimony of few; and number not voices, but weigh them.

What can I know? What ought I to do? What may I hope?

All trades, arts, and handiworks have gained by division of labor... Where the different kinds of work are not distinguished and divided, where everyone is a jack-of-all-trades, there manufactures remain still in the greatest barbarism.

Prudence reproaches; conscience accuses.

The infinitude of creation is great enough to make a world, or a Milky Way of worlds, look in comparison with it what a flower or an insect does in comparison with the Earth.

In law a man is guilty when he violates the rights of others. In ethics he is guilty if he only thinks of doing so.