Discourses, "To Those Who Fall Off Desist from Their Purpose" (§1)

“Consider as to the things which you proposed to yourself at first, which you have secured, and which you have not; and how you are pleased when you recall to memory the one, and are pained about the other; and if it is possible, recover the things wherein you failed. For we must not shrink when we are engaged in the greatest combat, but we must even take blows.”