Sometime during his first campaign on the northern frontier, Marcus, separated from his beloved Stoic friends and teachers back in Rome, started writing down his personal reflections on philosophy as a series of short notes and maxims. Reason allows us to step back and question whether what we desire is actually going to be good for us or not. His enemies in Rome will eventually succeed in murdering him when he is still only thirty-one years old. I noticed, though, that something wasn’t right—the way we approached the subject was too academic and theoretical. When someone complained that his philosophical arguments were very abrupt, Zeno agreed and replied that if he could he’d abbreviate the syllables as well.

After Socrates was executed, Xenophon faithfully wrote down many recollections of Socrates’s conversations about philosophy. His most powerful general in the eastern provinces, Avidius Cassius, was acclaimed emperor by the Egyptian legion, triggering a short-lived civil war. It allowed us to consider the example set by famous philosophers and whether or not they provide good role models. It allows us to evaluate our thoughts, feelings, and urges and to decide if they are good or bad, healthy or unhealthy. This puts a face to the philosophy and brings the ideas to life, while providing a Stoic ideal for the reader to strive for.I told Poppy that most people believe there are lots of good things—nice food, clothes, houses, money, etc. Among his tutors were experts on Platonism and Aristotelianism, but his main philosophical education was in Stoicism. Wisdom itself is uniquely valuable because it allows us to judge the value of external things—it’s the source of everything else’s value. I didn’t know it at the time, but that sort of existential anxiety is a common experience that drives people to the study of philosophy. Years later, after having lost several young children, Marcus was once again moved to tears in public while presiding over a legal case, when he heard an advocate say in the course of his argument: “Blessed are they who died in the plague.

Unlike other religious or spiritual practices, Stoicism does not require that you abandon reason or strain your grip on reality; rather, it provides an ethical orientation to life that is fully consistent with our nature as rational, social beings. He taught Xenophon that people should train themselves to acquire wisdom and virtue through self-discipline. Marcus lived to fifty-eight despite his frailty and illness and the harsh conditions he endured in command of the northern legions.

First he pictures Antoninus, his adoptive father, and then his adoptive grandfather, the emperor Hadrian. One way Stoics explained this was by saying that if we could put virtue on one side of a set of scales, it wouldn’t matter how many gold coins or other indifferent things piled up on the opposing side—it should never tip the balance. This allowed Marcus to continue to benefit from the personal instruction of Rusticus, even after Rusticus’s death, if only in his imagination. The air around him is still thick with the sweet smell of frankincense, which the Romans vainly hoped might help prevent the spread of the disease. Following Caesar’s assassination, his great-nephew Octavian became Augustus, the founder of the Roman Empire.

Fate permitting, more people may be able to apply the wisdom of Stoicism to the real challenges and everyday problems of modern living. As we’ll see, Zeno’s innovation was to argue that external advantages do have some value but of a completely different sort than virtue. The other three virtues can be understood as wisdom applied to our actions in different areas of life. For Stoics, virtue is still the only true good—the Cynics were right about that—but it’s also natural to prefer health to sickness, wealth to poverty, friends to enemies, and so on, within reasonable bounds.Looking back, I realize that I turned to Socrates and other ancient philosophers to find a philosophy of life like the one my father had found in Freemasonry. Marcus would often contemplate how these Stoic masters would themselves handle certain situations while also benefiting from personal instruction. Sometimes I’ve added minor details or pieces of dialogue to flesh out the story, but this is how, based on the available evidence, I imagine the events of Marcus’s life to have unfolded. Sure enough, Zeno became Crates’s follower, training in the Cynic philosophy founded by Diogenes of Sinope.