How appropriate that the gods put under our control only the most powerful ability that govern all the rest — the ability to make the right use of external appearances — and that they didn't put anything else under our control. Was this simply because they weren't willing to give us more? I think if it had been possible they would have given us more, but it was impossible.

— Epictetus, Discourses 1.1.7-8 (resource) Ryan Holiday, The 366 Meditations on Wisdom, Perseverance, and the Art of Living