The Stoic Worldview

First posted on the Stoicism Today blog. Now published in Stoicism Today: Selected Writings II (2016).

In my workshop at Stoicon 2015 I talked about Stoic physics and about its relationship with what we would today call religion and science. My aim was simply to try to give participants a sense of the broader ‘Stoic worldview’ beyond their practical advice about how to live well.

I Bodies

The Stoics begin with the claim that only bodies exist (Cicero, Acad. 1.39). Everything that exists is a physical thing. Anything that has any kind of causal power must ultimately be a physical body. So, if the Stoics claim that virtue impels us to act, for instance, and so has some causal power, then virtue must be a body. And they think it is: virtue is an excellent mental state, i.e. the physical soul organized in an optimal way. Closely connected to this claim that only bodies exist, the Stoics reject the existence of universals (i.e. Plato’s Ideas or Forms). Only particulars exist. So when they talk of ‘virtue’ they are not talking about some general concept or abstract ideal, which doesn’t exist, but rather about specific virtuous actions or specific optimal brain states. (Talk of brain states might sound anachronistic but it is pretty much what they have in mind.)

II Breath

They go on to claim that all bodies are composed of two principles or aspects: matter and ‘breath’ (pneuma) (Diog. Laert. 7.134). Matter is passive; breath is active. Breath is what makes things alive, and because everything is composed of both matter and breath, everything is alive. Breath comes in a variety of degrees of ‘tension’ (tonos) and the greater the tension the more complex the object. Inanimate objects such as stones have the lowest level of tension; living things such as plants have a higher degree; animals with the powers of sensation and movement are higher again; adult humans with rationality have the highest degree of tension. The higher the tension of the breath, the more complex the living organism will be (see Philo, in Long-Sedley 1987, 47P-Q). An important point here is that there is no difference in kind between a stone and a human being, only a difference in tension of breath (we might say a difference in internal organization or structural complexity; A.A. Long once proposed ‘wave-length’ as a way of thinking about this).

III Nature and God

The physical world, Nature as a whole, is a continuum and is infinitely divisible; the divisions between physical objects are to an extent only relative. Ultimately there is just one physical thing, Nature, of which we are all parts. The breath that structures and animates all of Nature the Stoics call ‘God’. Some sources say God is the breath, the soul of the world, just as the breath in our bodies is our soul. Other sources identify God with Nature as a whole, with the breath being his soul and the matter his body (the difference is between God being an animating force within Nature or simply being Nature). So, Nature is a living organism comprised of a soul and a body, breath and matter, and because, by definition, there is nothing greater than this, it, if anything is, must be God. On either view, we are fragments of God. If God is the world soul, the breath animating all of Nature, then the breath that animates us, our soul, is simply one part of that.

IV How Religious?

It is difficult to know how serious this talk of ‘God’ was. The early Stoic Cleanthes appears very sincere in his ‘Hymn to Zeus’, for instance, and we have no reasons to doubt his sincerity. However the Stoics were also well known for offering allegorical interpretations of the pagan Gods, including allegorical interpretations of the portraits of the Gods in Homer for instance. Famously, the Stoic Chrysippus once said that Zeus and his wife Hera are actually the active and passive principles in Nature, breath and matter. (In one source, Diog. Laert. 7.147, divine names for Nature are explained on the basis of their etymology.) Much later, in the third century AD, the philosopher Plotinus said that the Stoics bring in God into their philosophy only for the sake of appearances (Enn. 6.1.27). If ‘God’ is simply another name for Nature then it doesn’t really do much work in their philosophy; it doesn’t add or explain anything, so one might easily drop the word without any obvious loss. However the idea of a divine breath permeating Nature would later influence the Christian idea of a Holy Spirit (pneuma), and then would be interpreted by Church Fathers and others looking to harmonize Stoicism with Christianity right through to the seventeenth century. Perhaps that afterlife gives Stoic accounts of pneuma stronger religious overtones than they originally had. It is very hard to know. But again, Cleanthes’ Hymn appears quite sincere.

V How Scientific?

When the Stoics developed this idea of the soul as breath permeating the body they were doing so in dialogue the science of their day. In the image they give of the human soul comprised of a commanding centre with tentacles spreading pneuma (breath) throughout the body was inspired in part by the work of early anatomists (esp. Praxagoras; also Erasistratus) who were cutting open bodies and finding arteries and nerves. Chrysippus located the commanding centre of the soul in the chest (following Praxagoras), which of course contains the heart and arteries leading off it that spread through the entire body. (Praxagoras thought that arteries were pipes also connected to the lungs, carrying pneuma.) A later Stoic disagreed with Chrysippus and said the commanding centre of the soul was in the head, which of course contains the brain with nerves leading off it spreading through the entire body. This shift in position may well have been prompted by further observations (i.e. dissections): the distinction between arteries and nerves was still unclear in Chrysippus’ day and he commented that the scientific evidence was only tentative and one ought to wait for further discoveries. The important point to make here is that all this talk of a soul pervading and animating the body was actually part of a first step towards developing an account of the brain and nervous system. As crude as it may have been, this was a theory based on the cutting-edge scientific knowledge of the day.

VI Some Concluding Comments

The Stoics give us arguments for why we ought to think that Nature is rational, alive, and intelligent. We have those properties, nothing without those properties can give birth to something with them; therefore they must be properties of Nature (Cicero, Nat. D 2.22). (There are philosophers of mind today who continue to argue against the claim that consciousness could be an emergent property.) The Stoics then call this living Nature ‘God’. If Nature (or the Cosmos) encompasses everything, and if only bodies exist, and if God is something than which there is nothing greater, then it looks as if God must be identified with Nature. God cannot be anything lesser than Nature and cannot be anything outside Nature. However it remains difficult to know how seriously we ought to take this: is it a devout pantheism (you really ought to worship Nature), simply a deflationary use of language (when you say ‘God’ what you really mean is Nature), or a cautious pragmatism (rather than deny the existence of God, let’s call Nature ‘God’)? We do know the Stoics repeatedly engaged with (what we would now call) the science of their day: Chrysippus drew on the anatomist Praxagoras, the Stoic Posidonius studied botany and geology, a later Stoic, Cleomedes, wrote on astronomy, and Seneca wrote not just his ethical works but also his Natural Questions (on meteorology). The Stoics wanted to understand Nature because Nature taken as a whole is the greatest thing there is and we are parts of it. They aspired to a ‘smooth flow of life’, which they defined as a life in harmony with Nature, something that will require at least some appreciation of how Nature works. Whether we choose also to call Nature ‘God’ or ‘Zeus’ or ‘Gaia’ is perhaps less important.

What is a Stoic? Some Historical Reflections

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.