Carved on David’s sword in the Caravaggio painting David with the Head of Goliath is the acronym H-AS OS. It stands for humilitas occidit superbiam. Humility kills pride. It’s a line from St. Augustine, but Caravaggio, known for his beautiful, haunting realistic works, was a kindred spirit of the Stoics. (He himself carried a knife inscribed with nec spe, nec metu, “Without hope, without fear.”)

This idea that humility kills dangerous pride is at the core of Stoic philosophy. Marcus Aurelius was constantly humbling himself so the purple cloak of his emperorship didn’t go to his head. Seneca experimented with poverty so his wealth didn’t change him or become a burden. Cato would walk outsidebareheaded and barefoot, an appearance far below his station so he wasn’t corrupted by success and power.

These actions—and the meditations and words they poured over—kill pride. And we seek to kill pride before it kills the things we love, before it gets us into trouble that might even kill us.