 Hi, I'm Peter Adamson and you're listening to the History of Philosophy podcast, brought to you with the support of the Philosophy Department at King's College London and the LMU in Munich. Online at www.historyoffilosophy.net. Today's episode… Everybody Needs Some Body – Aquinas on Soul and Knowledge I haven't actually checked and I'm not sure how to go about doing so, but I would be willing to bet that there is as much scholarship devoted to Thomas Aquinas as to the rest of medieval philosophy put together. He's also the only medieval philosopher you're likely to study in a typical undergraduate philosophy degree. So I was rather surprised at what happened when I sought advice from several colleagues as to what I should cover in these podcasts on medieval philosophy. I had a sketchy plan already, which included quite a few episodes devoted to various aspects of Aquinas' thought, much as I've done in the past with figures like Plato, Aristotle, and Augustine. My expert advisors told me that this was unnecessary and even misleading. The most exciting scholarship is nowadays being devoted to other thinkers like Scotus and John Burredon. And it would be a distortion to give so much attention to Aquinas, who was in many ways unrepresentative of medieval philosophy in general and the late 13th century in particular. In this podcast series, we've come across many important thinkers who are not famous. With Aquinas, have we now reached a famous thinker who is not important? Well, as Bill Clinton might say, it depends on what the meaning of the word important is. In the modern day, Aquinas has unparalleled significance for the Catholic Church. His centrality was recognized in an encyclical in 1879 and reaffirmed by Pope John Paul II in 1998. And philosophers, Catholic and not, have recognized him as a thinker with innovative and fruitful teachings on the relationship between reason and religion, legal and political philosophy, the theory of action, epistemology, and many more topics besides. While his writings are not marked by the rhetorical elegance of a Plato or Augustine, they have a wonderful clarity which invites philosophical reflection. And his Latin is pretty easy too, which doesn't hurt. Nonetheless, there is one sense in which it is wrong to treat Aquinas as the most important medieval philosopher. He wasn't perceived as such in his time or in the generations following his death. His was an age during which Augustinianism continued to be dominant, even in the Aristotle-steeped world of the universities. In comparison to figures like William of Auvergne, Grosotest, Bonaventure, or Robert Kilwardby, Aquinas can be considered to be something of a radical Aristotelian. Some of his views attracted indignant, even uncomprehending reactions. Of course Aquinas himself would have rejected the label radical Aristotelian. Indeed, he attacked colleagues in Paris who were more radical still, the so-called Latin Averroists, to whom will be coming in due course. But the very heat of his invective against them may stem from his realization that he could all too easily be lumped in with the Averroists. Like a left-wing politician excoriating communists, for being even further to the left, Aquinas clashed with the Aristotelian extremists so as to emerge as a moderate. For corroboration, we need look no further than the 1277 condemnations of Paris. Unlike Kilwardby with his Oxford ban, the Bishop of Paris, Stephen Tampier, does seem to have had Aquinas in his sights. The Dominicans leapt to the defense of their fellow friar and began building the case for his rather early canonization in 1323. There are other signs of his high standing in the eyes of his contemporaries, such as his prominent appearance alongside other theologians in Dante's Paradiso. But if one were to choose the 13th century thinker whose ideas had most influence in the following century, then Duns Scotus, Henry of Ghent, or for that matter Albert the Great, would be at least as plausible choices as Aquinas. His emergence as the indispensable thinker of the Middle Ages was a slow one, and owes something to Renaissance authors like John Cabroll, the 15th century author of a work called Defenses of the Theology of Thomas Aquinas, and later in the 16th century, the great exponent of Aquinas, Cardinal Cajetan. All of which leaves me in a quandary. On the one hand, I assume most listeners will want to hear quite a bit about Aquinas, and I want to take advantage of the massive and sophisticated body of literature on his thought. On the other hand, I don't want to give him disproportionate coverage for the reasons just mentioned. The solution I've hit on is to compare his views to those of other 13th century thinkers. This will help to put him in context, and allow us to discover how idiosyncratic his ideas really were. I'll begin with the area of Aquinas' thought where he was most out of step with his contemporaries, his views on human nature and knowledge. Happily, I've prepared the way for this discussion in previous episodes. We've seen how prevalent it was to suppose that the human soul consists of numerous forms, and that many philosophers of the time made human knowledge depend on illumination from God. On both issues, Aquinas departs from the consensus. He's having none of these plural forms you'll find in other theories of soul, or rather, he's having one and only one of them. The functions of human life do not proceed from a multiplicity of forms, but just the one form that he identifies as the rational human soul. To some extent, this is just good Aristotle, at least as far as Aquinas is concerned. Every substance has a single substantial form, and each human soul plays that role for the human who possesses it. My soul provides me with all the features that are essential to me as a human being. Any other forms I may have will be accidental, like my baldness, my height, or my being located in Munich. Proponents of form pluralism found it incredible that just one form could produce such a wide variety of effects. When you order pizza, it would be responsible for everything from moving your body to the front door when the delivery arrives, to calculating the tip, to digesting the pizza after it's been consumed, to making your heart continue beating, however much of a struggle that might be given all the pizza you've been eating lately. But Aquinas thinks the pluralists are confusing the need for many forms with the need for many powers. Just one form can bestow many capacities on a substance, so long as that substance has many different parts for exercising those capacities. The presence of one and the same soul helps your heart to beat and your stomach to digest because your heart and stomach are such different organs. Like a reliable pizzeria, Aquinas' theory delivers what it promises, by securing the unity of the soul where form pluralism would, according to him, give us only an aggregate or heap. What we loosely refer to as lower souls, responsible for things like digestion and sensation, are only sets of capacities within the single form that is the rational soul. This is the position that Killwardby will condemn at Oxford. Aquinas wants to go even further than that though. He insists that the soul is the only substantial form to be found in each human. It is predicated directly of prime matter rather than coming on top of lower level constituents that are themselves substances. For example, there would be no actual elements, like fire and earth, in the human body, because if there were, the substantial forms of fire and earth would be present, and that would undermine the unity of the human substance. While the claim is a bold one, it isn't quite as crazy as it may first seem. Though Aquinas does not want to admit that there are any further full-blown substances within each person, he is happy to admit that the human has parts, like blood, bones, heart, and brain. Indeed, the soul itself is such a part. The distinction between distinct part and distinct substance may seem subtle, but for Aquinas it's crucial. Many scholastics believe that the soul is one substance and the body another substance. They like this idea, because it suggested that the soul could unproblematically survive the death of the body, something expressed by the popular analogy of a pilot in a ship, who can simply disembark and go on his way when his journey is at an end. But for Aquinas this is unacceptable, because the soul would have a merely accidental relation to the body. Besides, if that theory were true, we'd need some third intermediary principle to bind the body to the soul, whereas it was supposed to be the soul itself that unifies the human. Powerful though these considerations are, Aquinas's view faced more stiff opposition than the hero in a zombie movie. Bonaventure's student John Peckham was just one figure who insisted on form pluralism, condemning the Thomistic doctrine in 1284, a decade after Aquinas died. Another posthumous attack came from William de la Mer, whose correction of brother Thomas argued that a plurality of substantial forms could still constitute a unified soul if they worked together in a coordinated fashion. This critical treatise by William actually took aim at no fewer than 118 different teachings of Aquinas. Written in the late 1270s, it was made required reading among Franciscans, but provoked a defense from Aquinas's fellow Dominicans, evidence that the debates over Aquinas's orthodoxy began within just a few years of his death. One area where Aquinas's theory has surprising implications is the development of the human embryo. Given that today's Catholic Church is notable for its insistence that full-blown human life begins at conception, it's eyebrow-raising that Aquinas, the Church's most canonical thinker, doesn't think anything of the sort. Instead, Aquinas believes that the presence of a rational soul requires the presence of organs that can carry out its functions. Since this is lacking at early stages of fetal development, only the lower, nutritive or plant-like functions are present at first. They are succeeded by the functions of the sensory and motive powers, and finally by the advent of the distinctively human rational soul. The lower functions also have a different source than the powers of reason. They are brought out of the material provided by the parents, whereas the rational soul can be given only by God, and so is created directly in the embryo at some point during gestation. With the arrival of each new kind of soul, the previous form is destroyed or discarded and replaced with the new single and unified form, which however retains the powers available to the previous forms that were in the embryo. As you might expect, scholarly ingenuity has been devoted to reconciling this teaching with that of the modern Church. Obviously, the generation of a fetus is in some sense a continuous process, and at the very least Aquinas will want to say that the early embryo has the potential to become the human that will actually develop some weeks later, so there's some prospect of harmonizing the two positions, or at least minimizing the tension between them. Everything we've seen Aquinas saying so far can be understood as his way of explaining the Aristotelian definition of soul as the form of the body. So seriously does he take this definition that he's now left with a serious problem. How can the soul be immortal? If the soul is not accidentally related to body, like a pilot is related to a ship, but is the substantial form of that body responsible for even such humble and obviously physical processes like digestion, how could it possibly still exist after death? Aquinas comes dangerously close to denying that it can do so. He thinks the soul's disembodied condition is unnatural to it and that the soul will be unable to exercise many of its powers in that condition. In a way, that's good news, since it gives him a sound basis for insisting on the need for eventual bodily resurrection, which is of course standard Christian doctrine. But he still needs to persuade us that the soul can somehow avoid vanishing between the moment of bodily death and the future time when it gets its body back. Here he points to Aristotle's claim that intellectual thought is a purely immaterial process requiring no bodily organ. Before it's seated in an organ, the mind's processes would be particularized and thus unable to engage in general universal thinking. And if the mind can engage in its distinctive operation without using the body, then it can survive the death of the body. But Aquinas seems to be trying to have his pizza and eat it too. On the one hand, the mind must act without the body in order to think universally. On the other hand, my mind is only my mind because it is a power of my soul, and my soul is only my soul because it is tied to my particular body. This is a point on which Aquinas really needs to insist. Unlike some of the radical Aristotelians who were active in Paris around the same time, he absolutely rejects the proposal of the Muslim commentator Averroes that there is only one intellect for all of humankind, befitting the universality of intellect of thinking. Instead, the mind borrows the individuality of the soul, which is in turn individual because it is the form of one individual body. This explains an obvious fact, which Aquinas never tires of invoking against Averroes, when a person thinks it is that person and not anyone else who is thinking. Furthermore, even if thought itself is an immaterial process, Aquinas insists that the body plays a vital role in human knowledge. He takes very seriously another remark of Aristotle's that thinking always requires a phantasm or imaginary representation. If you had never encountered pizza, you would be unable to imagine or represent it to yourself, and that would mean, tragically, that you couldn't think about it at all. It may seem that thinking about pizza in general, picturing the pizza you are hoping to have later, and actually seeing and tasting a particular pizza are rather similar processes, but a Aquinas thinks there is a big leap from seeing or imagining pizza to thinking about pizza. Non-human animals can do the former quite readily, just think of what a dog does when the scent of freshly delivered pizza reaches its nose. But animals can't think universally about pizzas or anything else, according to Aquinas. They are incapable of the immaterial grasp of an intelligible form freed from all particularity, particularity that is present even when you are imagining or remembering pizza, since you are then grasping one particular image, a process that, unlike Intellect, does depend on the body. How do we manage the trick of universal thought where other animals cannot? It's here that other thinkers, like Bonaventure, would invoke divine illumination. According to them, it is our imperfect access to the exemplars in God's mind that lends perfect intelligibility and certainty to our highest thought processes. It's traditional to contrast that illumination theory, which has its roots in Augustine, to the hard-nosed Aristotelian empiricism of Aquinas. But Aquinas agrees with the illumination theory to some extent. He too thinks something further is needed in order to transform the particular images of sensation, imagination, and memory into the universal ideas present in our minds. This extra topping on the pizza of Aquinas' epistemology is the Agent Intellect. Again, he here takes issue with many of his predecessors, especially thinkers of the Islamic world like Avicenna, who postulated a single Agent Intellect that activates thinking in the individual minds of particular humans. No, says Aquinas, it is true that some principle is needed to confer actual intelligibility and universality on our representations of things, but that principle is within the human soul. Each of us is created by God with our own Agent Intellect, a natural light that we carry within us and that we can use to illuminate the images of things we have encountered in the world around us. From the point of view of his contemporaries, this could seem a rather feeble gesture in the direction of agreement with Augustine. Aquinas was duly subjected to further criticism, for instance by yet another Franciscan, a student of John Peckham's named Roger Marston. He insisted that illumination was needed from outside the soul. The Agent Intellect is not a power of the human soul, but nothing less than God himself. From our point of view, however, Aquinas may seem to be striking a balance between the illumination theory and a more extreme form of empiricism. He thinks that humans are born with everything they need to think abstract universal thoughts, but denies that such thoughts require no more than the particular images we glean through sensation. As for the charge that he is cutting God out of the story of human knowledge, this is easy to rebut. After all, the natural light that dwells within each of us was given to us by God when he infused our rational souls into our developing bodies. So that's what Aquinas has to say about the metaphysics of soul and the process by which we achieve knowledge. We also saw last time how Aquinas situates naturally acquired knowledge within theology. But there's one more thing we might want to know. Why is it so important to have knowledge anyway? So important, Aquinas would say, that it is one reason we are given bodies in the first place. We won't be able to understand the role of knowledge in the good human life without talking more about that good life. That will mean tackling the question of what Aquinas understands by happiness, which is, for him, as for Aristotle, the central concept in ethics. To illuminate his ideas on that subject, I'll be juxtaposing Aquinas's ethical teaching to that of his own teacher, Albert the Great. So join me for that when it's time for the next special delivery of the History of Philosophy without any gaps.