Discourses, "That We Ought Not to be Moved by a Desire of Those Things Which Are Not in Our Power" (§6)

“Having these things (or thoughts) always in hand, and exercising them by yourself, and keeping them in readiness, you will never be in want of one to comfort you and strengthen you. For it is not shameful to be without something to eat, but not to have reason sufficient for keeping away fear and sorrow.”