Meditations 5:15

Nothing pertains to human beings except what defines us as human. No other things can be demanded of us. They aren't proper to human nature, nor is it incomplete without them. It follows that they are not our goal, or what helps us reach it—the good. If any of them were proper to us, it would be improper to disdain or resist it. Nor would we admire people who show themselves immune to it. If the things themselves were good, it could hardly be good to give them up. But in reality the more we deny ourselves such things

(and things like them)—or are deprived of them involuntarily, even—the better we become.