Book IX · 16
Not in passivity but in activity lie the evil and the good of the rational social animal, just as his virtue and his vice lie not in passivity but in activity.3
Not in being acted upon but in activity lies the evil and the good of the rational and civic creature, just as his virtue too and his vice lie in activity and not in being acted upon.
Marcus Aurelius, Meditations IX.16. Translated by George Long (1862). The Stoic Library.