The Enchiridion (9-11)

Sickness is an impediment to the body, but not to the will, unless itself pleases. Lameness is an impediment to the leg, but not to the will; and say this to yourself with regard to everything that happens. For

Upon every accident, remember to turn towards yourself and inquire what faculty you have for its use. If you encounter a handsome person, you will find continence the faculty needed; if pain, then fortitude; if reviling, then patience. And when thus habituated, the phenomena of existence will not overwhelm you.

Never say of anything, I have lost it; but, I have restored it. Has your child died? It is restored. Has your wife died? She is restored. Has your estate been taken away? That likewise is restored. But it was a bad man who took it. What is it to you by whose hands he who gave it has demanded it again? While he permits you to possess it, hold it as something not your own; as do travellers at an inn.