 Hi, I'm Peter Adamson, and you're listening to the History of Philosophy podcast, brought to you with the support of King's College London and the Leverhulme Trust, online at www.historyoffilosophy.net. Today's episode, We Didn't Start the Fire, The Stoics on Nature. This, in the translation of the indispensable long and subtly reader entitled The Hellenistic Philosophers, is the beginning of a hymn to Zeus written by the Stoic Cleanthes. Cleanthes, as you might remember, was the successor of Zeno, the founder of Stoicism, and the predecessor of the great Chrysippus. It shows us that a pious attitude towards the divine was at the heart of early Stoicism, and this may come as a surprise. Anyone with a passing knowledge of Stoicism will know that, like the Epicureans, they were materialists. They insisted that what really exists is what can act on something, or be acted upon by something else. And this, for them, means bodies. Thus, they agree with Aristotle in dismissing Platonic forms as a fantasy. How could something like the form of large actually make anything large? You make things large by, for instance, in inflating them with air, or stretching them with your hands. Whatever changes we see are caused by the interaction of bodies. Aristotle had likewise complained that Plato's forms could not accomplish anything, but the Stoics are going further than he did. After all, Aristotle did invoke an immaterial God as the primary cause of his cosmos. Yet the Stoics too included God in their vision of the cosmos. In fact, they quite literally included God in the cosmos, seeing him as a physical being that pervades all things. Here they again mention their idea, which, incidentally and ironically, is borrowed from Plato, that what exists is what can act or be acted upon. In general, they see God as the active cause in the universe, and speak of matter as the passive cause that is acted upon. But this is a slippery distinction, because in fact God is never apart from matter. The acting cause is never apart from what it acts upon. Instead, God and matter are both physical principles which in their permanent and mutual interaction form the body of the cosmos. Thus, the Stoics are willing to call their God nature, rather than seeing the divine as something supernatural, as might be suggested by Aristotle. Indeed, later in the history of philosophy, there will be a long tradition of seeing the title of Aristotle's metaphysics as appropriate precisely because it studies that which is after or beyond nature, namely God. By contrast, the Stoic God is immanent, physically interwoven through all bodily things, and so through everything that exists. But if he is physical, what kind of physical thing is he? Here the Stoics reach back into the pre-Socratic past for inspiration, making common cause with, of all people, Heraclitus. He had portrayed God as a fire, or as a thunderbolt that steers all things, an idea that appears in our quote from Cleanthes' hymn. Following Heraclitus, Stoics too describe God as having a fiery nature, although God is not to be imagined simply as a flame, such as you see rising from the wick of a candle. The sense in which God is fire is more that he is physically subtle and active. He is also unlike earthly fire in that his activity is not blind or mindless. To the contrary, the Stoics call God a designing fire, and also a craftsman or demiurge, echoing the name given to God in Plato's Timaeus. He does not just pervade the cosmos, but wisely and artfully builds it from within, as if the carpenter's designing skill were inside wood and able to make it into a table. For this reason, the Stoics point to the apparent design of the world around us as a proof of God's existence. This kind of proof, often called a design argument, was certainly on the table, if you'll pardon the expression, in Plato's Timaeus, and in the works of Aristotle. But the Stoics make it very explicit, claiming that it is just obvious that there is a pervading principle of wisdom in the world. In a weird and striking image, Zeno said that rejecting the existence of such a principle would be like encountering a tree that grows flutes that play tunes, and then denying that there is a principle of music in the tree. Another Stoic analogy says that if we saw a model of the heavens, we would never question that it was made by an artisan. Thus, how can we doubt that a wise artisan made the real heavens? The Stoics see every feature of the cosmos as the result of divine wisdom and purpose, claiming that all things are as good as they could possibly be, and devoted to the fulfillment of God's plan. Often, God's plan coincides with our own. My favorite detail from Stoic design arguments comes when they claim that pigs are clearly designed by providence to be food for man, because their flesh is naturally salty. Now I know what you're thinking. God is a principle of order and activity, but is imminent within the body of the cosmos. Doesn't this sound less like a god and more like a soul? Doesn't it in fact sound a bit like the so-called world soul of Plato's Timaeus? To this I say, good point, and thank you for paying such close attention. The Platonic world soul is of course immaterial, but in other respects it is indeed comparable to the Stoic god, which is likewise woven together with the body of the cosmos. In fact, one could see Stoic theology as itself woven together, taking both the world soul and the divine craftsman of Plato's Timaeus and combining them into one single principle. It would seem that this is not a coincidence. The early Stoics were carefully reacting to Plato, borrowing from him, even as they rejected some of his ideas, not least the ideas or forms themselves. That was incompatible with their materialism, but the comparison of god to a craftsman, the analogy between the cosmos and the living thing, the notion that providence and wisdom are visible in the design of the universe, all these things were taken over from the Timaeus and given a distinctively Stoic materialist spin. Quiantes says in his hymn that we alone among earthly beings bear a likeness to god, which looks like another Platonic allusion to the dialogue Theaetetus and its suggestion that mankind's purpose is to achieve likeness to god. Of course, as materialists, when the Stoics say this they must mean that the soul is a physical thing, which somehow resembles the divine nature that physically pervades all things. Our souls can be thought of as portions of this divine nature, and they give to our body what god gives to the world, order and a principle of activity. The human soul is also, like god, fiery. Starting with Chrysippus it is identified with a kind of warm breath, in Greek pneuma. Thanks to this breath, living animals possess a vital heat that spreads along with the soul through the body, just as god the designing fire spreads through the cosmos. The Stoics naturally locate the center of the soul where we find the center of heat, namely, as Aristotle too had said, the heart. It is here, not in the brain, that we find the soul's so-called hegemonicon, or commanding faculty. Of course, the Stoics knew that their materialist understanding of soul would be no less contentious than their materialist portrayal of god, so they argued for it. One proof they offered was that children resemble their parents in character as well as in appearance. Parents produce their children through a physical process, so how could our character dispositions be inherited if the soul were not somehow physical? They also describe the way that the soul physically acts upon and within the body. Taking their cue from respiration, they imagine the soul as a kind of breath that is moving both inward and outward in the body, holding the body together in a balanced state of tension. Actually, something like this is true even for lifeless things such as rocks, which also have a so-called tenor. This is what holds a rock together as a single thing and makes it distinct from the other objects around it. But humans have a much more exalted sort of unity, which gives them the god-like capacity for reason and intelligence. Here the Stoics run into a problem. They are saying that god and the soul are physical things which spread all the way through other physical things, namely the cosmos and the ensouled body. But how is this possible? It seems to presuppose something absurd, namely that two physical objects can be in the same place at the same time. If only this were true, it would solve all our housing problems. But unfortunately, each physical object seems jealously to guard its own space. Some kind of force is needed to push it out of its place to make room for something else. When I pour wine into a glass, for instance, the air in the glass is pushed out of the way. So it seems that god cannot be everywhere in the cosmos because there is no room. The cosmos would have to get out of the way. But, the Stoics can now ask, what happens when wine is poured into water? In that case, the wine does not push the water aside. Rather, it mixes together with the water, so that the two are both together in the same place. Similarly, the Stoics want to say, god is thoroughly mixed together with the body of the cosmos, and your soul is mixed together with your body. This theory of mixture provoked a good deal of discussion and derision in the ancient world. Of course, some philosophers, like the atomists, thought that there is no total mixture, only the juxtaposition of particles, jumbled together only the way that pebbles or beans might be. Chrysippus, author of the Stoic view on this issue, did of course agree that mixture can happen by juxtaposition, but he insisted that two things can be in the same place at the same time, if they are suitable for this more thorough kind of mixture, like wine and water. Opponents retorted that, in that case, any body could be stretched to be coextensive with any other body, no matter how large. A drop of wine could be mixed into the entire ocean, and would be stretched across the whole ocean a little bit of that drop in every drop of water. A gorier version, suggested by the sceptic Archesilaus, pointed out that if Chrysippus were right, a single leg that rotted in the ocean could become big enough for two fleets of ships to fight in, since the decomposed leg would spread throughout the entire sea. If this was supposed to scare Chrysippus, it didn't work. He insisted that a drop of wine can in principle exist throughout the sea. His opponents, of course, continued to feel that he didn't have a leg to stand on. The Stoic god, then, is not only a source of all order and activity, which steers all things like Heraclitus' thunderbolt, but is also present within all things. He could hardly be more unlike the Epicurean gods, who are envisioned as uninvolved, remote entities living in detached bliss. The Stoic god, by contrast, is about as involved as he could be. Indeed, Stoic physics in general is diametrically opposed to Epicureanism. Instead of unmixed atoms colliding at random, we have divisible and intermixing bodies woven together by a providential rationality. A more subtle contrast for the Stoics would be Aristotle. Of course, his god, like a Platonic form, is an immaterial cause, something the Stoics reject out of hand. But the Stoics agree with Aristotle, and most other ancient philosophers, in thinking of the cosmos as spherical, with the more divine heavens surrounding an earthly realm. They accept a system of four elements, air, earth, fire, and water, and, like Aristotle, assume that these are continuous, in other words they can be divided and divided again, indefinitely, without ever reaching atoms, that is, indivisible parts. Thus, the Stoics find much to agree with in Aristotle's physics. Regarding the past and future, though, they do not see eye to eye. Aristotle believes that the cosmos is eternal, and has always been organized more or less as we see now. For the Stoics, though, the world order we experience is only one chapter in an ongoing story. Long ago, the cosmos consisted of nothing but divine fire, a pure fusion of God with matter, in which all was wisdom and there was no evil. Our world emerged from this state when the fire condensed into the other elements and, as in many a pre-Socratic cosmology, transformed into the earth below and the heavens above. Also familiar from pre-Socratic philosophy, even if it is an idea that turns up too in some Platonic dialogues, is the idea that our world undergoes cycles. The Stoics believe the cosmos will revert to its original state, in a so-called conflagration, when it will be consumed in fire and be reduced, or rather increased, to nothing but fire. I say increased because the Stoic theory takes account of the fact that the elements vary in density. When fire transforms into water or earth, it takes up much less space, and the reverse, of course, is also true. This means that when the cosmos is in a state of conflagration, it will take up vastly more room than it does when it has partially condensed into its current form. To make this possible, the Stoics posit that our cosmos is surrounded by an infinite emptiness, a void. Here again, it's useful to compare them to the Epicureans and to Aristotle. Aristotle rejects the possibility of void entirely. For him, the cosmos is a finite sphere surrounded by nothing at all, not even empty void. Epicurus instead goes for an infinite void, the emptiness in which atoms can move and collide, combining into indefinitely many worlds. Like Aristotle, the Stoics recognize only one cosmos, our cosmos. But, they say it is able to expand in volume because there is plenty of room around it, since they also recognize infinite void, like the Epicureans. Against Aristotle and whoever else doubts that the cosmos is surrounded by void, the Stoics ask what will happen if someone standing at the very edge extends his arm. If he can stretch his arm out past the edge of the cosmos, there is empty space around it. If he can't, there must be something outside the cosmos blocking his motion. So, if the cosmos really does have an edge with nothing beyond it, then nothing must be conceived as void. When the Stoics combine their cosmic cycle with their respect for divine providence, they come to an unnerving conclusion. God designs the whole world with maximal wisdom. Presumably then, when the world has been consumed in fire and reborn, we can expect God to make the same choices again. Every cosmic cycle, in other words, will be exactly the same. This is the idea of eternal recurrence, also famously discussed by Nietzsche. It is not merely an idle cosmological speculation, but is intended to make us weigh up each choice as if it will be repeated infinitely many times. That, at least, was the message Nietzsche drew from the idea of recurrence. Marcus Aurelius, too, saw it as ethically important, but for a rather different reason. It puts things in a great deal of perspective. For instance, why should I be afraid to choose an honourable death over cowardly safety if my life will be repeated in infinity of times so that I will live forever either way? To draw this sort of moral, of course, Marcus and other Stoics need to believe that it will literally be me who exists again and again in cycle after cycle of the world. Some Stoics denied this under pressure from their critics, but it seems that the original Stoic view here was that the very same Socrates will exist in every world cycle, will drink hemlock in every cycle, and so on. It has even been suggested that time for the Stoics is therefore circular. If this is right, the Stoics see the future not as an infinite series of repeated events that are exactly alike, but as a loop of literally identical events happening over and over again. This may be captured in the image of time as an unwinding rope, which Cicero uses to describe the Stoic theory. But how, we might now ask, can Marcus Aurelius, or any other Stoic, speak of choosing whether or not we choose with eternal recurrence in mind? If God so orders the world as to achieve the best and most rational results, and if our actions too fall within that ordering, then can we really be said to choose our actions? Are we not rather puppets of divine causation? The Stoics might, like later philosophers, have sought to reconcile divine providence with the idea that our actions are uncaused by God, or by anything else, but they went in the other direction. They embraced the notion that all things are caused, including human actions. They were, in a word, determinists, convinced that all events, including human choices and actions, arise out of unbreakable chains of prior events, a web of cause and effect that is inescapable and the product of divine wisdom. As I've said in previous episodes, the Stoics saw all parts of philosophy as interconnected, and we've here arrived at a connection between physics and ethics. In fact, we already saw that the physical doctrine of eternal recurrence had a practical significance. Determinism, though, has further-reaching consequences for ethics. The thought that all things are fated to occur as they do by divine providence might fill us with a deep peace, leading us to accept even the most horrifying events with equanimity. We might, that is, take what we have come to call a Stoic attitude towards misfortune and suffering. What happens is inevitable, so there's no point getting upset about it. Moreover, it is preordained by God, and getting upset would just be to show our all-too-human incomprehension of his greater plan. On the other hand, this same thought might itself strike you as pretty upsetting. It seems to depict us as mere pawns moved by irresistible divine will in a cosmic chess game, albeit a game of chess that happens over and over, with a big fire breaking out at the end. So is nothing to put it, as the Stoics and other philosophers of the period put it, up to us? It's up to you to find out, by joining me next time as I look at Stoic ethics and determinism on the history of philosophy without any gaps.