Meditation 4.18
Marcus AureliusMeditationsBook 4.18
18. How great a rest from labour he gains who does not look to what his neighbour says or does or thinks, but only to what he himself is doing, in order that exactly this may be just and holy, or in accord with a good man's conduct. 'Do not look round at a black character,' but run toward the goal, balanced, not throwing your body about.