The ancient Greek and Roman philosophical school — founded by Zeno of Citium in Athens around 300 BCE — that taught that virtue is the only true good, that external circumstances are 'indifferent,' that we can control our judgments but not outcomes, and that living according to reason and nature is the path to flourishing: a philosophy that shaped Roman imperial culture, influenced early Christianity, and has undergone a remarkable 21st-century revival as a practical philosophy of life.
Marcus Aurelius was the most powerful man in the world. He ruled an empire of 70 million people, fought wars on multiple fronts, and faced plague, rebellion, and family tragedy. He also kept a private journal — never intended for publication — in which he reminded himself, repeatedly, of Stoic principles: that he could control his judgments but not outcomes, that virtue was sufficient for happiness, that he should treat obstacles as opportunities for practice. The Meditations is one of the most extraordinary documents in world literature: a Roman emperor trying, and often failing, and trying again, to live philosophically.