 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.historyofphilosophy.net. Today's episode, Soul Power, Aristotle's De Anima. Are you comfortable on that sofa? I want you to relax. This is a safe space. Nothing that's said within these walls will leave the room. You aren't being judged. I'm here to help. So shall we start at the beginning? Tell me a little bit about your mother. Yes, today on the History of Philosophy, we're doing psychology. But actually, don't start to unburden yourself, especially if you're listening to this while on public transport. Because we're actually going to be doing Aristotelian psychology, which has less to do with uncovering your true character and the traumatic experiences of your childhood, and more to do with uncovering the true nature and experiences of the soul. This is as it should be. As you won't be surprised to learn, the word psychology comes from ancient Greek. The Greek word συέη means soul, so psychology is simply the study of the soul. And the very first work devoted to psychology is of course Aristotle's On the Soul, commonly known by its Latin title De Anima. With all due respect to James Brown, it is really Aristotle who deserves the title Godfather of Soul. Now I know what you're thinking. Aristotle's De Anima, the first work on the soul? What about Plato? He wrote the Phaedo, after all, which not only depicts the last moments of Socrates's life, but also proves the soul's immortality, not just once, but numerous times. Surely that counts as an earlier work on psychology? Well, yes, what I mean is not that the De Anima is the first work to focus on the soul, but that it is the first work to attempt a general, systematic discussion of soul. As we saw when we looked at the Phaedo, Plato simply assumes the distinction between soul and body, and he examines the capacities and properties of the human soul only in passing, since the main topic of the dialogue is to prove the soul's immortality. By contrast, Aristotle mentions the soul's immortality only in passing, but he discusses just about every other possible question regarding the soul, starting with the question of just what we mean by tsuke, or soul. It's worth dwelling on this question. As in the physics, the work we looked at over the last few episodes, Aristotle begins his discussion here in the De Anima by surveying previous views on the topic at hand. And it's clear that in this case, one of his objectives is to determine just what topic is at hand. He looks to his predecessors to formulate a kind of checklist of questions that a theory of soul should answer. The pre-Aristotelians, including Plato, generally presume that soul is somehow distinct from body, so this is one question, how does soul relate to body? Then, there is the question of why we are positing a soul in the first place. What is the soul supposed to do? What does it even mean to say that something has a soul? Perhaps most obviously, soul is meant to explain life. Aristotle is thus comfortable ascribing soul to anything that is alive, which means that for him, not only humans, but also animals, and even plants, have souls. This is going to be important for Aristotle, because if there are plant souls, animal souls, and human souls, then souls can be very different from one another. My soul is going to have something in common with the soul of a sunflower, because both are souls, but equally, my soul and the sunflower's soul will be different. They will differ in terms of what abilities they confer on the living being. Sunflowers don't do much. They take in nutrition, they turn towards the sun, they grow, and with all due respect to sunflowers, that pretty much exhausts their repertoire. I, by contrast, can do all these things. If you're ever in London and the weather is unusually good, you can swing by and watch me turn towards the sun. I'm really good at it. But I can do many other things in addition, such as see, talk, move from place to place, and on good days, think about Aristotle. Considering his predecessors, Aristotle finds that soul has indeed been associated with just this sort of range of capacities. In particular, he finds that soul is associated with motion and with perception. He takes both of these in a rather broad sense. When the sunflower takes in nutrition, that counts as motion. This is the way the sunflower displays its internal principle of change, which, as we saw a couple of episodes ago, is its nature. But plants do not perceive, at least according to Aristotle. For that, we need to rise a level up the food chain to animals, who are capable not only of sense perception, but also of motion from one place to another. These are linked, Aristotle believes, because the animal needs perception to find its food, and needs the capacity for motion to go after that food. Again, we see his commitment to the idea that nature has to do with internal principles of change, and of course also his commitment to teleology, the idea that everything that is natural to a plant or an animal will serve the purpose of its flourishing. If it is natural to sunflowers to turn towards the sun, and for giraffes to trot towards acacia trees, this must be because these behaviours contribute to their well-being. Another thing Aristotle learns from his survey of previous views is that there are two extremes to be avoided in thinking about how soul relates to the body. At one extreme are strongly dualist theories of soul. According to these theories, the soul is an entirely different entity from the body. The two just happen to co-exist, as it were. This would apply to Plato's immaterialist theory of soul, but also materialist views like those espoused by the atomists, where soul is made up of particularly round, fast-moving atoms located within the atomic compound that is the animal. It is, as it were, a body within the body. The problem with these dualist views is that they dissolve the unity of the living being, making it hard to see why the soul's relation to body is intimate, rather than casual. As Aristotle says when criticizing the atomist theory, why can't the soul just flow out of the body and wander away? At the other extreme, there is the view that soul is nothing more than a certain harmony or arrangement of the body. This idea is criticized also in Plato's Phaedo, and Aristotle agrees with the criticisms. The soul must be able to exert causal influence on the body, for instance by initiating motion. It's hard to see how this could happen if the soul were a harmony any more than the tuning of the strings on a guitar can make the guitar play by itself. This leaves Aristotle right where he likes to be, occupying the middle ground. On his view, the soul will not be just another body, as the atomists proposed, but neither it will be some separate entity with a merely accidental connection to the body as Plato seems to hold in the Phaedo. To reach a compromised position, Aristotle reaches for his favorite distinction between actuality and potentiality. As we saw in a previous episode, he uses this distinction to account for change and motion. When James Brown slides across the stage doing his signature dance move, he actualizes his potentiality for dancing. But this distinction isn't yet refined enough to provide the basis for Aristotle's psychology. We need to make a further distinction between two kinds of potentiality. On the one hand, there is the kind of potentiality exercised when James Brown suddenly starts to dance. On the other hand, there is the kind of potentiality he possessed as a child, before he even knew how to dance. As a child, what James Brown had was the ability to acquire an ability, or, to put it in Aristotle's terms, the potentiality for acquiring a potentiality. Aristotle thus distinguishes between what he calls first potentiality and what he calls second potentiality. First potentiality is the ability to gain an ability, second potentiality is the ability you already have. The insight here is that second potentiality is itself a kind of actuality, even though it isn't necessarily active at any given moment. When James Brown is backstage getting ready for the show, he's actually able to dance, but he isn't actually dancing. So we can also call second potentiality the actual ability, first actuality, to contrast it to the second or full actuality that occurs when we actually exercise our abilities. Aristotle gives a similar example, which suffers from its failure to involve James Brown, but makes the same point. You have the child who can learn mathematics, who is in first potentiality, the mathematician who is not doing mathematics, for instance because he is asleep, and this is second potentiality, which is the same thing as first actuality, and then there is the mathematician actually doing mathematics. This is second actuality, as actual as it gets. You may already be able to guess what all this has to do with the soul. We already saw that plants, animals, and humans all have souls, but of different kinds. The difference in kind is bound up with a difference in abilities. Plant souls enable plants to engage in nutrition and reproduction, but nothing else. Animal souls bestow upon their possessors the power to perceive and to move around, and human souls bring the capacity for thought. In his survey of previous views on the soul, Aristotle has already given us to understand that soul is defined in terms of such capacities. That was in Book I of the Deianima, and it has carefully prepared the way for his definition of soul in Book II. The soul, he says, is the first actuality of a living body. It is first actuality, or if you prefer, second potentiality, because having a soul is simply having a range of actual capacities or abilities. Which abilities you get depends on which kind of soul you have. If you are a sunflower, your soul will help you to live and produce more sunflowers. But if you are James Brown, you have the most complex and multifaceted kind of soul there is. You can live, perceive, think, and of course, dance. No wonder they called him Soul Brother Number One. Let's pause for a moment to compare Aristotle's idea here to the ideas put forward by contemporary philosophers of mind. Philosophy of mind is devoted in part to discussing the question of how mental phenomena relate to physical phenomena. Like Aristotle, most contemporary philosophers are suspicious of extreme answers to this question. Only a few would say that we could entirely abolish talk of the mental, so that proper science would need no concepts of desires, thoughts, or intentions. Equally, very few want to say with Plato and Descartes that the mind is a separate substance which is only casually related to the body. So today's philosophers of mind tend to occupy the middle ground, along with Aristotle. And there are almost as many ways of doing that as there are philosophers of mind. However, we should note a major difference between these philosophers and Aristotle, which is easy to overlook. Aristotle's theory is not in fact a theory of mind, it is a theory of soul. For him, the soul explains mental events like seeing, desiring, and thinking, but it also explains functions like digestion, reproduction, and growth. It is obvious to him that plants have souls, whereas it is equally obvious to us that plants do not have minds. In short, what Aristotle talks about in the Deonema is a principle of life, not a principle of mental life, which we usually call consciousness. This complicates any attempt to situate him relative to the contemporary debate. Having defined soul as a kind of actual capacity or set of capacities, it is clear what Aristotle needs to do next. He needs to examine the various kinds of psychological capacities in turn, giving a philosophical account of them in ascending order of nobility. This is exactly what he does, more or less covering nutrition and sense perception in the rest of Book II, and the higher cognitive powers of thinking and imagination in Book III. The remarks about thinking are among the most influential, but also controversial, passages Aristotle wrote, and I am going to return to them in a future episode. For now, I want to concentrate on nutrition and sense perception. In both cases, Aristotle refers us back to another issue he has covered in the survey of his predecessors. There, he told us that there was a dispute among the pre-Socratic thinkers, regarding the question of how one thing can affect another thing. Some philosophers, Aristotle says, believed that in order for causal interaction to occur between two things, they must be dissimilar. For instance, if something cold is going to be acted on so that it changes, it will need to be acted on by something hot. But other thinkers insisted that two things must share some nature if they are to interact. For instance, Empedocles thought that the sense organs need to be made of all four elements, so that they can sense all four elements. Thus, we have a classic dialectical opposition, the sort of opposition Aristotle delights in dissolving by showing that there is, as Tony Blair argued, a third way. In this case, the third way is provided by the increasingly familiar contrast between potentiality and actuality. Thanks to Aristotle, we know that when one thing heats another, this can occur because something potentially hot encounters something else that is actually hot. For instance, a cold rock is brought near to a fire. The actually hot fire actualizes the potential heat of the rock. This solves the presocratic puzzle, because the rock is in a way like the fire and in a way unlike it. It is like the fire because it is hot in a way, that is, potentially hot, and unlike the fire because it is not hot in another way, that is, it is actually cold. The point seems simple, but, unlike the third way of Tony Blair, pays massive dividends, once we get to the topics of nutrition and sensation. With regard to nutrition, Aristotle can explain that food nourishes us because it is potentially the sort of stuff our bodies are made of. You may remember that Anaxagoras thought there must be flesh and bone in cheese, because when we eat it, our flesh and bone are restored and even increased. As usual, Aristotle can take the slightly patronizing attitude that this theory is a good try, but not quite right. Instead, what we should say is that there is no flesh and bone actually in the cheese, but the cheese is potentially flesh and bone. And anything that is alive, whether plant, animal, or human, will have a nutritive power, which simply is the power to actualize that potentiality. Just as the fire heats the rock, so the cheese-eating animal turns the cheese into flesh and restores itself. The same kind of story can be told regarding sense perception. Consider what happens when you see. When you are not seeing, like if you're asleep or your eyes are closed, you are of course potentially seeing. You just need to wake up to open your eyes, and if those eyes are in good working order, you'll see whatever is in front of you. Again, you might be able to guess what Aristotle will say. Just as the actually hot fire actualizes the potentially hot rock, so the actual colors and shapes of the objects in front of your eyes will actualize the potentiality of your vision. Aristotle takes this rather literally. He says that if you see, for instance, a red apple, your vision goes from being potentially red to being actually red. The redness of the apple simply activates the potential redness of sight, and when that happens you see red. I just said that Aristotle takes this rather literally, but there is in fact a debate about just how literally. Some scholars, most prominently my guest from last week, Richard Sarabji, have proposed that the physical organ, the eye itself, literally turns red. This is encouraged by the fact that Aristotle says that the fluid in the eye must be in itself colorless, since otherwise it would not be able to take on all the colors that we see. Other interpreters, sometimes called spiritualists, think that the eye or vision becomes red when we see red, but not in a literal physical sense. Rather, for vision to become red is simply for us to have the experience of seeing red. This all has interesting consequences for lining up Aristotle with contemporary philosophy of mind, since on Sarabji's reading the eyes turning red would be identical with seeing red. That is, my eye fluid turned red, and I saw red, would be two different descriptions of the same event. This sort of account is prominent among philosophers of mind nowadays. But however literally we take Aristotle's theory, it is clear that sensation is, for him, nothing but the actualization of a capacity on the part of the animal, or human, that engages in perception. If we go back to Aristotle's definition of soul, this makes perfect sense. What you get by having a soul is, as we said, a whole range of capacities which will be actualized or not depending on your circumstances. Some functions will be actual pretty much all the time, for instance the power to breathe and produce the warmth needed to keep you at body temperature. These things go on even while you sleep. But most other functions shut down while you sleep. In terms of actual activity, sleeping people who aren't dreaming are much like plants. But even sleeping people have the capacity to do a wide range of things, from moving, to seeing and hearing, to thinking. Just shake them so they wake up, and they will manifest some or all of these capacities almost immediately, for instance the capacity to be annoyed that one has just been woken up for no good reason. Part of what Aristotle's de onima has done, then, is to sketch out the principles for a much larger project, which we could call biology. Aristotelian biology would study all living organisms, whether plant, animal, or human. In this project, Aristotle's ideas about nature and psychology would come together. He would explore in detail his teleological idea that all natural beings have purposes which they naturally pursue, and his idea that each living thing has a different kind of soul, which brings with it a specific range of capacities. After all, it isn't only the case that plants, animals, and humans have different capacities, so do different kinds of plants, like sunflowers as opposed to Venus flytraps, and different animals, like giraffes as opposed to gorillas. From this point of view, the de onima can be seen as simply the first step in the direction of a systematic biology in which the full range of living organisms would be explored and explained on Aristotelian principles. Did Aristotle undertake such a project? You bet your life he did, as we'll see next time on The History of Philosophy Without Any Gaps.