Who Were the Stoics?

Stoicism is often spoken of as though it were a single set of teachings handed down intact. It was nothing so tidy. The Stoic school was a living tradition that ran for close to five hundred years, from its founding in Athens around 300 BCE to the death of the emperor Marcus Aurelius in 180 CE and beyond. Across that span its members argued, refined and openly disagreed, while holding to a shared conviction that the good life is the life lived according to reason and virtue. To ask who the Stoics were is to follow that long conversation through three broad phases and a remarkable cast of individuals: a shipwrecked merchant, a former boxer, an exiled teacher, a man born into slavery and an emperor among them.

The school took its name from a building. When Zeno of Citium began teaching in Athens, he gathered his students not in a private garden, as the Epicureans did, but in a public colonnade on the north side of the marketplace: the Stoa Poikile, or Painted Porch, so called for the murals of myth and battle that adorned it. His followers became known simply as the people of the Stoa, the Stoics. From the beginning, then, this was a philosophy practised in the open, amid the traffic of the city rather than withdrawn from it.

Historians conventionally divide the school’s five centuries into three phases. The early Stoa, in Greece across the third and second centuries BCE, is the period of the founders, who built the system across logic, physics and ethics. The middle Stoa, in the second and first centuries BCE, is the period in which the philosophy travelled to Rome and softened some of its sharper edges. The late or Roman Stoa, in the first and second centuries CE, is the period of the writers we read most today, who turned the school’s attention firmly toward ethics and daily practice. The division is a modern convenience and the boundaries are not clean, but it offers a useful map of a tradition in motion.

These three set the doctrines that later Stoics inherited: a single rational principle, the logos, ordering the whole of nature; a strict ethics in which virtue alone is good; and a confidence that careful reasoning could guide a human life toward flourishing. Much of what they wrote is lost, but the framework they built held firm for centuries.

As Rome rose, Stoicism travelled west, and two figures of the second and first centuries BCE carried it into the Roman world. Panaetius of Rhodes, who led the school in the later second century, moved among the Roman elite and belonged to the circle around the general Scipio Aemilianus. He gave Stoic ethics a more practical and humane cast, attending to the duties of public life and relaxing some of the school’s harder claims. His work on appropriate conduct reached later readers through Cicero, whose treatise On Duties drew heavily upon it.

Posidonius of Apamea, a student of Panaetius, was among the most learned figures of the ancient world: a philosopher, historian, astronomer and geographer whose researches ranged from the tides to the workings of the mind. Teaching at Rhodes, he drew distinguished visitors, Cicero and Pompey among them. He revised parts of Stoic psychology, granting the emotions a less purely rational source than orthodox doctrine allowed, in a move that brought him closer to Plato. With the middle Stoa, the philosophy became less a closed Athenian system and more a body of thought in dialogue with Roman concerns and with other schools.

It is from the Roman period that Stoicism survives most fully, and it is here that the philosophy turns its gaze most insistently to the conduct of a life. The four figures below could hardly have differed more in station, and that range is itself part of the Stoic point: the philosophy claimed to be available to anyone, in any circumstance, who would take up the work.

Anyone who reads about the early Stoics soon meets a frustration: almost none of their writing remains. The hundreds of treatises by Zeno, Cleanthes and Chrysippus are lost, surviving only as fragments and as reports in the works of others. Our knowledge of the early school is therefore reconstructed, pieced together from quotations, summaries and the accounts of later writers, some sympathetic and some hostile.

The chief sources are a handful of ancient compilers and critics. Diogenes Laertius, in the seventh book of his Lives of the Eminent Philosophers, gives the fullest single account of early Stoic doctrine. Cicero, himself trained in several schools, preserved a great deal of Stoic ethics and theology in his philosophical dialogues. The anthologist Stobaeus gathered valuable extracts, while critics such as Plutarch, Sextus Empiricus and the physician Galen reported Stoic views in order to dispute them, conserving them in the act of attacking them. In modern times these scattered remains were assembled by scholars, most famously in the collection known by its Latin title as the Stoicorum Veterum Fragmenta, and rendered for English readers in sourcebooks such as Long and Sedley’s Hellenistic Philosophers.

By contrast, the Roman Stoa survives in something closer to its own voice. We have Seneca’s essays and letters, the record of Epictetus made by Arrian, and Marcus Aurelius writing to himself. This is one reason the later Stoics dominate the popular image of the school: not necessarily because they were its deepest thinkers, but because their words came through.

A slave and an emperor, a statesman and an exile: what unites these figures is not their fortunes, which could hardly be more varied, but their shared conviction that a good life is built from character and judgement, and that these remain within reach whatever fortune sends. That claim has proved unusually durable. Stoic ideas shaped early Christian thought, were rediscovered in the Renaissance, and have surfaced again and again wherever people have looked for a way to live steadily in unsteady times.

Their problems are recognisably ours: how to keep our heads under pressure, how to act well toward others, how to face loss and our own mortality without despair. The Stoics did not claim to have removed these difficulties, only to have found a way of meeting them. That is why, two thousand years on, a shipwrecked merchant and a worried emperor still have readers.