Sophie's World: A Novel About the History of Philosophy

Heraclitus pointed out that the world is characterized by opposites. If we were never ill, we would not know what it was to be well. If we never knew hunger, we would take no pleasure in being full. If there were never any war, we would not appreciate peace. And if there were no winter, we would never see the spring.

You can’t experience being alive without realizing that you have to die, she thought. But it’s just as impossible to realize you have to die without thinking how incredibly amazing it is to be alive.

Democritus once said that he would rather discover a new cause of nature than be the King of Persia.