This quote comes from Marcus Aurelius's personal writings in Meditations, composed during his military campaigns as Roman Emperor (161-180 CE). In this reflection, Aurelius articulates a core principle of Stoic philosophy about responding to injury without compromising one's own values. The emperor, drawing from his extensive experience managing both an empire and military campaigns, suggests that maintaining our ethical standards in the face of wrongdoing is more powerful than retaliation. This principle particularly resonated with his dual role as both a philosopher and leader of the Roman Empire.