Meditation 9.4-7
Marcus AureliusMeditationsBook 9.4
4. Whosoever does wrong, wrongs himself; whosoever does injustice, does it to himself, making himself evil.
5. Often he who omits an act does injustice, not only he who commits an act.
6. Sufficient are the present judgement that grasps its object, the present social act, the present disposition well satisfied with all that comes to pass from a cause outside the self.
7. Wipe out imagination: check impulse: quench desire: keep the governing self in its own control.