A single lifetime, even though entirely devoted to the sky, would not be enough for the study of so vast a subject. A time will come when our descendants will be amazed that we did not know things that are so plain to them.

To be able to endure odium is the first art to be learned by those who aspire to power.

There is no evil that does not offer inducements. Vices tempt you by the rewards which they offer.

Wisdom teaches us to do, as well as to talk; and to make our words and actions all of a colour.

As long as you live, learn how to live.

Life without the courage to die is slavery.

Who can hope for nothing, should despair for nothing.