The Enchiridion (9-10)

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.