This reflective and solitary work was written by one of the best of the "good" Roman emperors, Marcus Aurelius (A.D. 121-180), during the course of his military campaigns against barbarian hordes who were threatening the borders of his empire. His Meditations are among the noblest expressions of the principles of Stoic philosophy, which stressed the virtues of reason, thoughtful deliberation, and moderation as guides to right conduct in an uncertain world.