When you wake up in the morning, tell yourself: The people I deal with today will be meddling, ungrateful, arrogant, dishonest, jealous and surly. They are like this because they cannot tell good from evil. But I have seen the beauty of good, and the ugliness of evil, and have recognized that the wrongdoer has a nature related to my own – not of the same blood and birth, but the same mind, possessed of a share of the divine. And so I cannot be harmed by any of them, as no one can implicate me in ugliness. Nor can I feel angry at my relative, or hate him. We are made for cooperation, like feet, like hands, like eyelids, like the rows of upper and lower teeth. To work against each other is unnatural. And to feel anger at him, to turn your back on him: that is unnatural.
Stoic philosophy, Roman Emperor