A couple of quite different projects I have been working on recently have required me to have a view about how to define a Stoic. Here are some thoughts. Some of this material comes from my introduction to The Routledge Handbook of the Stoic Tradition. It is also posted on the Stoicism Today blog.
What is a Stoic? Who counts (or counted) as a Stoic? One might think the best way to answer these questions would be to point to a core set of doctrines and say that anyone who holds or held those doctrines is or was a Stoic. Alternatively one might focus on following Stoic guidance, living a Stoic life; someone who does this is a Stoic.
Who counted as a Stoic in antiquity? There are problems with trying to follow the ‘core set of doctrines’ approach. Even in its original incarnation in Athens, Stoicism was not a fixed set of doctrines adopted by unthinking disciples. The Hellenistic Stoics were philosophers and, like all philosophers, were prone to argue among themselves. The Roman Stoic Seneca famously said “we Stoics are not subjects of a despot; each of us lays claim to his own freedom” (Ep. 33.4). Some scholars have tried to downplay this remark, suggesting that as a rule members of all the Hellenistic schools had a strong sense of loyalty to the school’s founder, in this case Zeno of Citium.
Zeno founded the “school” in Athens around 300 BCE, after having studied with the Cynic Crates, the Megarian Stilpo, and Polemo in Plato’s Academy (Diog. Laert. 7.2). It was not Zeno but, so the story goes, the school’s third head Chrysippus of Soli who really developed Stoicism into a systematic body of thought. Chrysippus is reported to have written some 705 books (7.180). As Diogenes Laertius put it, “if there had been no Chrysippus, there would have been no Stoa” (7.183). However the idea of a philosophy as an abstract system of thought is very much a modern one, gaining currency in the eighteenth century, even if the Stoics did emphasize the unity of their own philosophy (see e.g. Diog. Laert. 7.41-3). How unified Chrysippus’s “philosophy” was remains an open question. One of our most important sources is the later Platonist Plutarch who quotes seemingly contradictory passages from works by Chrysippus in order to show the contradictions inherent in Stoicism. Yet it is almost impossible to judge Plutarch’s claims when the quotations are all out of their original context. Contradictory passages might come from works written decades apart, for instance. If Chrysippus was the great philosopher many in antiquity claimed him to be then surely he could have developed his views and changed his mind over time. There may never have been a single unified thing that we could call “Chrysippus’s philosophy” consistently maintained over 705 books, even if some subsequent Stoics may have tried to summarize that vast output.
In the ancient world and for a long time after, histories of philosophy were written as histories made up of philosophers, not philosophies, with those philosophers grouped into schools. The story of the Hellenistic Stoa is above all a story about a series of individual philosophers who self-identified as “Stoics”. Initially this reflected the fact that the founding members of the school met at a particular place, the Painted Stoa on the northern edge of the Agora in Athens, but over time came to reflect a commitment to a shared set of philosophical views. (It is worth noting that Zeno’s earliest followers called themselves “Zenonians”, only adopting the name “Stoics” later on (see Diog. Laert. 7.5). The change perhaps reflected a desire not to be bound by the doctrines of the founder.) Even so, as Seneca’s comment highlights, the Hellenistic Stoics did not agree upon everything and we have numerous reports of later Stoics disagreeing with the supposedly orthodox Stoic view on one topic or another. Well-known examples include Aristo of Chios on the distinction between different types of “indifferents” (Diog. Laert. 7.160) and Boethus of Sidon on the cosmos being a living being (7.143). These both look like central Stoic doctrines, yet neither of these Stoics felt compelled to leave the school and they were not forced out by those they disagreed with either. Aristo is forever labelled a “heterodox Stoic” but the fact remains he did remain a Stoic, and didn’t run off to become a Cynic.
We might wonder whether there was indeed a core set of philosophical views to which all Stoics subscribed, or simply a set of philosophical family resemblances that meant no one doctrine was sacrosanct, or perhaps just an ever-developing tradition of thought that happened to be able to trace a line of succession back to Zeno’s gatherings at the Painted Stoa. However one might try to answer that question, the point I would like to make here is that the Hellenistic Stoa was itself a developing tradition of thought, founded by Zeno, strongly identified with Chrysippus, but embracing a wide range of other philosophers too, from Aristo and Cleanthes to Panaetius and Posidonius. In traditional accounts Panaetius and Posidonius are presented as so-called “Middle Stoics”, heterodox and eclectic when compared with their predecessors. The extent to which Posidonius, for instance, was heterodox has been challenged in recent years, but even if he were, the preceding variety and dispute within the school would not make him out of place. (To repeat: this is what philosophers do, they argue among themselves!) Even in the Hellenistic period, then, Stoicism was a rich and diverse movement, a complex living tradition.
The living tradition of masters and pupils who could trace their lineage back to Zeno was over by the end of the Hellenistic period. The last recorded heads of the school were Mnesarchus and Dardanus (Cicero, Acad. 2.69). Cicero, who wrote our earliest and in some ways most important accounts of Stoicism, visited Athens at a time when the Athenian schools were more or less at an end, but he did manage to attend the lectures of Posidonius in Rhodes, making him one of the last people to have first hand knowledge of the Athenian Stoic tradition. The first few centuries of our era saw many philosophers who explicitly identified themselves as Stoics but they now depended on texts for their knowledge of Athenian Stoic philosophy.
One of the first and most famous of these “text-based Stoics” was Seneca. Seneca embraced the title “Stoic” but was happy to draw on ideas from Epicurus when he found them reasonable (again: he was a philosopher, not a religious convert). He also studied in the philosophical school of Sextius, via whom he adopted a number of Pythagorean ideas and practices (and many of the practical exercises that Seneca exhorts and people now think of as distinctively “Stoic” in fact had their origins in Pythagoreanism). So Seneca drew on ideas from a number of sources but chose to self-identify as a Stoic. He was also in close contact with a number of others who embraced Stoicism, including his nephew Lucan, Cornutus, and the poet Persius who is reported to have owned a collection of more or less all of Chrysippus’s works. This was a new, local Stoic community of friends.
Around the same time, Musonius Rufus lectured on Stoicism in Rome and his lectures were attended by a slave called Epictetus, who would go on to found his own school in Nicopolis on the western coast of Greece after gaining his freedom. Students at Epictetus’s school studied works by Chrysippus, while continually being reminded to apply Stoicism to their daily lives. Reports of Epictetus’s lectures were recorded by one of his students, the historian Arrian, and these proved to be a decisive influence on the young Marcus Aurelius, who wrote his own notes “to himself” towards the end of his life. Again we see a mix of what we might call “text-based Stoicism” and the creation of new Stoic communities.
The texts of Chrysippus were still readily available during this period, as we can see from the frequent quotations in authors such as Plutarch and Galen; by late antiquity these were seemingly all lost. Since then the reception of Stoic ideas has been closely bound up with the transmission of texts either by later Stoics (Seneca, Epictetus, Marcus Aurelius) or by other, often hostile, authors reporting Stoic views. In the Latin West the principal sources were always Seneca and Cicero.
The reception of Stoic ideas since antiquity has differed from Roman Stoicism in two ways: first, later readers have taken Roman authors as their main source of information rather than having access to works by the Hellenistic Stoics; and second, the vast majority of those readers were for a very long time sincerely or otherwise publically committed to Christian doctrine and so did not affirm every Stoic idea they encountered. They welcomed some doctrines but rejected or were silent about others. In this they were no different from the Roman Stoics themselves or even many of the Hellenistic Stoics, as I have tried to show.
What does all this mean for the question “What is a Stoic?”? Since the first century BCE “text-based Stoicism” has involved people reading Stoic texts, finding some things they like but perhaps a few other things they don’t, reflecting their own temperament, judgement, existing beliefs, and cultural background. Some of those who think they agree with a significant amount of what they find choose to adopt the title of “Stoic”. Others prefer to avoid labels. Each personal encounter with the ideas in the texts will of course be unique. Each stands on its own terms. It will be more or less impossible to judge which of these is “properly Stoic” given that there never was a single set of definitively agreed Stoic doctrines upheld by all the philosophers of antiquity who were members of the Athenian Stoa. Instead what we see is a series of family resemblances.
The phrase “modern Stoicism” is a perfectly good one for referring to the recent upsurge of interest in Stoicism as a source of practical guidance for everyday life. It indicates that people don’t claim to be resurrecting an ancient system of thought as a whole, but instead taking what they find useful and applying it in a modern context. However it would be a mistake to think that “modern Stoicism” might be defined as a set of doctrines, in some way abstracting the core ideas of ancient Stoicism and updating them for the modern world, against which individuals might in some way be judged as “Stoics” or not (and which itself might be judged as not properly “Stoic” enough). Instead there are just people who read Stoic texts, take what they find agreeable or useful, and in some cases chose to self-identify as Stoics. That’s how it has been for a very long time.