Stoicism was born in Athens, but it came of age and to power in Rome, a story that mirrors the life of Panaetius of Rhodes, who would become one of Stoicism’s great ambassadors to the world. We know that in 155 BC, Diogenes and his diplomatic mission had successfully introduced Stoicism to the growing empire, which would absorb the philosophy into its DNA. But it actually may have made a brief appearance thirteen years earlier when Crates of Mallus, a Stoic philosopher from Pergamum, was sent on his own mission to Rome to protect his country’s interests in the Macedonian Wars.

Breaking his leg in a fall, Crates spent months recuperating and discoursing on philosophy with small audiences of Romans. As it happens, Panaetius’s father was in Rome on his own diplomatic mission at the same time as Crates’s convalescence. Did he attend his lectures? Bring home copies of the discourses that had spread through Rome in the form of poems and commentaries? Or did he bring his son with him on one trip and send him to see Crates directly?

Soon enough, the young Panaetius was a student of Crates back in Pergamum, the future diplomat and connector having been introduced to philosophy through a fortuitous diplomatic connection.

We don’t know much about Panaetius’s studies under this early Stoic, but clearly they were designed to prepare him to follow in his father’s footsteps and into the track that Diogenes and Antipater had set for future Stoics: serving the public good. In 155 BC, Panaetius was appointed to the position of sacrificial priest at Poseidon Hippios in Lindos. It would be the first of the many public roles he would serve in his active life.

Whatever he learned on this job, it became clear to Panaetius that he needed more formal education as well. He eventually made his way to Athens to study under Diogenes, now world-famous after his own diplomatic mission to Rome, and Diogenes’s protégé, Antipater. It’s as if Panaetius returned to get his PhD in philosophy—this second phase of education in Athens would last roughly five years—and then went right back to the real world once more, where he got to work applying what he’d learned at the highest levels of influence and power in Rome.

Learn. Apply. Learn. Apply. Learn. Apply. This is the Stoic way.

During his time in Athens with Diogenes, Panaetius met a fellow student of Diogenes named Gaius Laelius, with whom he would continue to study. Through Laelius and then later, on a naval contingent, Panaetius met and served with Scipio Aemilianus, one of Rome’s great generals, an adopted son of one of its most powerful families and a lover of Greek thought and literature.

Back in Rome, these three men then formed a kind of philosophical club—known to historians today as the Scipionic Circle—that would meet in Scipio’s enormous houses to discuss and debate the Stoic philosophy they all pursued. Scipio footed the bill, Panaetius provided the intellectual nourishment. Many others joined them in these discussions and were shaped by them. Not unlike the way that the expat scene in France after the First World War nurtured the careers of Hemingway, Stein, and Fitzgerald, or how a company like PayPal would give the world Peter Thiel and Reid Hoffman and Elon Musk, the Scipionic Circle became a kind of breeding ground for influential Stoics and a generation of leaders. Publius Rutilius Rufus, who defied Rome’s culture of corruption and who you will meet in the next chapter, was often present. The historian Polybius was too.

It was a form of influence and access that neither Panaetius’s father, nor his teachers, Crates and Diogenes, could have imagined possible. Scipio, with time and with Rome’s growth, became the most powerful man in the Greek world. The kings of Greece now answered to him and to Rome as vassals, while Panaetius served as a kind of translator and advisor and confidant.

Some historians today debate just how often the Scipionic Circle met and how direct its influence was. But there was little of this doubt about its significance in the ancient world. Velleius Paterculus records in his History of Rome that Scipio “kept constantly with him, at home and in the field, two men of eminent genius, Polybius and Panaetius.” He describes Scipio as being deeply devoted to the art of war and peace, saying that he was constantly “engaged in the pursuit of arms or his studies, he was either training his body by exposing it to dangers or his mind by learning.”

Cicero, who was fascinated by stories of Panaetius, sprinkled his dialogues with scenes and anecdotes from these meetings. Later writers like Plutarch not only had no doubts about the Circle, but tell us of the kind of quiet political influence Panaetius managed to exert. In Moralia: Precepts of Statecraft, Plutarch writes that “it is a fine thing also, when we gain advantage from the friendship of great men, to turn it to the welfare of our community, as Polybius and Panaetius, through Scipio’s goodwill towards them, conferred great benefits upon their native States.”

This is what Panaetius had trained for—directing policy and shaping powerful decisions that affected millions of people.

Where Zeno was a founding genius and Chrysippus was the cleaver to the Academy’s knots, while Aristo favored absolutism over pragmatic direction and Antipater moved in the opposite direction of trying to lay out rules for everyday life, Panaetius was a kind of weaver—tying Stoic and Roman ethical perspectives together, introducing philosophical consideration to Rome’s elite with one hand, subtly directing them to protect and service the interests of his distant homeland with the other. Effectively, the Stoa had a supremely well-placed and practical ambassador in Rome.

The timing could not have been more essential.

It’s not hard to detect a provincialism in the early Stoics. Zeno insisted on his hometown being inscribed next to his name on a building he had paid to restore. Cleanthes’s frugal lifestyle had little room for travel, let alone concern for international affairs. Even Diogenes had quickly returned to Athens after his trip to Rome. These were not attitudes well fitted to a global empire.

Panaetius was, unlike his predecessors, a born globalist. His life began in Rhodes but expanded when he studied abroad in both Pergamum and Rome. He traveled across most of the Mediterranean. He fell in with Romans fascinated by the East. Panaetius was able to manage and integrate all these diverse and conflicting ties in a surprisingly modern way. Marcus Aurelius would, in Meditations, describe himself as a “citizen of the world,” and in so doing was following the new course for the philosophy that Panaetius had first set.

Yet even with this international mindset, Panaetius never lost his connection to where he came from. When Athens offered him citizenship, he politely declined, saying that “one city was enough for a sensible man.”

All were aware that Panaetius had a moderating effect on the frenetic yet practical Scipio, balancing out his ambition with mildness and principles. But he was clearly no wet blanket, or he would not have been able to cultivate such a vivacious and diverse social circle. Scipio got enough out of Panaetius’s company that in the spring of 140 BC he asked him to accompany him on an ambitious embassy to the East. This mission was recorded in many sources and logged stops across Egypt, Cyprus, Syria, Rhodes, and various places in Greece and Asia Minor. Plutarch writes that Scipio summoned Panaetius directly, and another source explains that the Senate sent them to “to view the violence and lawlessness of men.” Today we might call this a “fact-finding mission.”

We like to think that the world has changed a great deal since Panaetius’s time, but the truth is that senates are still sending men to the same regions to make the same kinds of observations that this soldier and philosopher were dispatched to make more than twenty-one hundred years ago—just as we are still struggling to strike the right balance, as Panaetius did, between nationalism and globalism, the concerns of the many and the concerns of ourselves.

In the way that Zeno followed in his father’s trade, so too did Panaetius, the son of a diplomat and the student of two philosopher diplomats, continue the family business—and continue Stoicism’s transition from the Stoa to the levers of power, from the provincialism of the Athenian agora to the world stage. In a time when many still believed that the gods played an active role in human affairs and when sacrifices and ritual were designed to placate them, Panaetius was a freethinker. He rejected the silly theories of soothsayers and astrologers, and it was likely on his advice around this time that Scipio banned them from his regiments.

Plutarch tells a colorful story from this nearly two-year fact-finding mission in his Moralia: Roman Sayings that, when Scipio arrived in Alexandria, traveling in a retinue which included Panaetius and five servants, the people were in such a frenzy that they yelled for Scipio to take his toga off his head so they could get a good look, and when he did the masses burst into applause. He writes that the Egyptian king Ptolemy “the Fat” VIII “could hardly keep up with them in walking because of his inactive life and his pampering of his body, and Scipio whispered softly to Panaetius, ‘Already the Alexandrians have received some benefit from our visit. For it is owing to us that they have seen their king walk.’”

Fat and lazy heads of state are another recurring character of history.

In 138 BC, Panaetius and Scipio returned to Rome. Panaetius was now forty-seven years old and had gained a wide life experience. His schooling long finished in Pergamum and Athens, an interim public career in Rhodes behind him, including time spent in the navy, he now found himself ensconced in the inner workings of Rome. It was again timeless and modern that he would, as so many men do at that age, begin to turn some of his attention to writing.

His most important book, Concerning Appropriate Actions, which is an extended meditation on ethical behavior in public life, was not merely theoretical. As he was finishing it, Scipio, who still depended on Panaetius for advice and guidance, began prosecuting a series of major corruption cases against Roman politicians. One against Lucius Cotta was an extortion case. Another involved the Gracchus affair and Scipio’s brother-in-law, Tiberius Gracchus. Antipater’s ethical teachings partly encouraged this populist revolt (his student Blossius was a ringleader), which sought to distribute lands to the poor, but Panaetius found himself on the other side of it. It was the role of the ruling class to defend and maintain order—and Scipio’s aggressive prosecution of the Gracchus affair is interesting in that it essentially pitted two Stoic leaders against each other. We have the Stoic revolutionary in Blossius and the Stoic conservative in Panaetius, both fulfilling what they believed to be their duty to the state. It’s not so much a strange coincidence of history as rather a natural outgrowth of Stoicism’s increasing integration into the political world. Of course, Panaetius would find himself in the middle of a fierce conflict where he knew all the parties involved—that’s what happens when you’re connected.

Cicero would write that Concerning Appropriate Actions “has given us what is unquestionably the most thorough discussion of moral duties that we have,” no small statement given that a hundred years later, Cicero would find himself navigating political revolution as Caesar overthrew the Republic. The previous Stoics had sometimes actively flouted social convention, but Panaetius saw each human being as having a unique prosopon, Greek for “character” or “role,” that must be fulfilled with honor and courage and commitment, however humble or impressive.

Panaetius argues that if we are to live an ethical life and choose appropriate actions, we must find a way to balance:

  1. the roles and duties common to us all as human beings;

  2. the roles and duties unique to our individual daimon, or personal genius/calling;

  3. the roles and duties assigned to us by the chance of our social station (family and profession);

  4. the roles and duties that arise from decisions and commitments we have made.

Each of these layers is an essential part of living virtuously in the real world. A soldier has to manage their obligations as a human, as a warrior, as a member of a family (or as an immigrant or as a wealthy heir), and as a person who has made promises and commitments (to friends, to families, to business partners). The pieces of the equation are different for a head of state or a beggar, but the complicated balance—and the need for guidance—is the same.

When we say that Panaetius was a connector, then, we don’t just mean that he connected people like some kind of master networker—though he was one. More than just searching for obscure ideas in books, he was connecting timeless principles with real people for use in their real lives.

It’s not just the fate of the modern man and woman to ask: Who am I? What should I do with my life? How can I make my life count? The ancients struggled with this too, and Panaetius’s formula helped them as it can help us.

Panaetius believed that each person had an inborn desire for leadership, and that we are obligated to fulfill this potential in our own unique way. We may not all be able to be Scipio on the battlefield, or even Panaetius with an elite education and diplomatic connections, but we can serve the public good in many other ways with equal courage. That’s really what the Scipionic Circle was—a diverse collection of men of vastly different talents, stations, and interests all trying to find a way to contribute and thrive in the world.

Everyone can have a life of meaning and purpose. Everyone can do what they do like a good Stoic.

Panaetius, we can imagine, was the one friends often turned to for advice about how best to do so, and it was aphormai (our inborn resources) that Panaetius pointed them to. It would be a theme, in fact, carried forward by Stoics through to the writings of Marcus Aurelius. Humanity is given these instincts toward virtue by nature, and we can thrive and live nobly if we learn to live consistently with our own nature and our duties, while making the most of the resources we have been given. Panaetius, while born to privilege, chose not to settle into that comfortable life of ease. Instead, he openly embraced duty and the responsibility of a much broader stage. He took the resources he was given and leveraged them, becoming the best version of himself and contributing as much as he could to the big projects of his time.

Each of us, he believed, is obligated to do the same.

Unlike the all-or-nothing race of a runner like Chrysippus trying not to shove his way to victory, Panaetius took the model of a different kind of athlete when reflecting on how best to fulfill our social duties. He thought the pankratist (the practitioner of pankration, a Greek form of boxing) was a supreme model for capturing the tensions and essence of living a virtuous life. His pankratist is one of the most powerful and illustrative sports metaphors, not just in Stoicism, but in all of philosophy.

As Aulus Gellius records:

Of an opinion of the philosopher Panaetius, which he expressed in his second book On Duties, where he urges men to be alert and prepared to guard against injuries on all occasions. “The life of men,” he says, “who pass their time in the midst of affairs, and who wish to be helpful to themselves and to others, is exposed to constant and almost daily troubles and sudden dangers. To guard against and avoid these one needs a mind that is always ready and alert, such as the athletes have who are called ‘pancratists.’ For just as they, when called to the contest, stand with their arms raised and stretched out, and protect their head and face by opposing their hands as a rampart; and as all their limbs, before the battle has begun, are ready to avoid or to deal blows—so the spirit and mind of the wise man, on the watch everywhere and at all times against violence and wanton injuries, ought to be alert, ready, strongly protected, prepared in time of trouble, never flagging in attention, never relaxing its watchfulness, opposing judgment and forethought like arms and hands to the strokes of fortune and the snares of the wicked, lest in any way a hostile and sudden onslaught be made upon us when we are unprepared and unprotected.”

It’s a metaphor of Panaetius’s creation that would appear, uncredited, in the works of Marcus Aurelius and Epictetus—two philosophers who battled their way through life. Unlike Antipater’s archer, who captured the reality of the many things out of our control as we seek to choose well among life’s challenges, or Aristo’s javelin thrower, Panaetius saw life as less theoretical and much more violent and forceful. It wasn’t just a contest with oneself, but actual combat—with opponents and fate. He believed we need to be prepared for the blows that will inevitably fall upon us.

Ultimately, Panaetius would not finish the book, for reasons unknown. But what he had captured in writing was an incredible achievement and was recognized as such in his own time. One of his most politically active students, Publius Rutilius Rufus, who also served Scipio in the Numantine War in 134 BC and was involved in reforms of military training, taxation, and bankruptcy, explained that even this partial work towered over the philosophical and political world: “As no painter had been found to complete that part of the Venus of Cos which Apelles had left unfinished (for the beauty of her face made hopeless any attempt adequately to represent the rest of the figure),” he said, “so no one, because of the surpassing excellence of what Panaetius did complete, would venture to supply what he had left undone.”

For all that he left unsaid, so much was said and established that allowed Stoicism to thrive in Roman political life for the next three hundred years. Cicero claimed, for instance, that Panaetius argued it was possible for a good lawyer to defend a guilty client—provided they were not egregiously depraved or wicked. Not only is it a position that makes sense given Panaetius’s deep belief in each individual’s duty and role in life, but it is also a practical innovation that has been a pillar of the legal system over the last two thousand years: If no one steps up to defend undesirable clients, how can we be sure that justice is being done?

Panaetius was a simple and direct writer as well as speaker who helped rid the philosophy of arcane terminology and its unappealing style—undoubtedly the result of his Stoic teachers’ early influence. More importantly, he made the philosophy itself more practical and accessible for people. As Cicero explained, “Panaetius strove to avoid [the] uncouth and repellant development of Stoicism, censuring alike the harshness of its doctrines and the crabbedness of its logic. In doctrine he was mellower, and in style more lucid.”

He was one of the first Stoics who seems to be less a philosopher and more like a great man. Stoics like Zeno had said that virtue alone was sufficient for happiness, which is simple and true enough but light on instruction. According to Diogenes Laërtius, Panaetius was the first Stoic to believe that virtue was not self-sufficient, “claiming that strength, health, and material resources are also needed.”

Panaetius knew that none of this philosophizing existed in a silo; it is interconnected with other important things. It is in the balance, the integrating of competing obligations and interests and talents that the good life is found and lived.

In 129 BC, Scipio would die, a dear loss to both the Republic and to his friends. We can imagine Panaetius grieving this loss, but also relying on an exercise he had taught his students. Suppose your son dies, he said. You must remind yourself that you knew he was mortal when you brought him into the world. The same is true for friends, he would have had to reassure himself. The same is true for careers.

All things end. Philosophy is there to remind us of that fact and to prepare us for the blows of life.

After the death of Scipio, Panaetius understood that a chapter of his life had ended—all that was left was for him to write the next (and possibly the final) one. He returned to Athens that same year after another great loss—this time the death of Antipater—to take over as head of the school. There he served the Stoa another twenty years, continuing to teach and write. Perhaps, like retired political figures today, he returned occasionally to Rome to lecture, consult with magistrates, or promote his books.

And then he too, in 109 BC, passed from the earth.