 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 historyofphilosophy.net. Today's episode, Opposites Attract, Nicholas of Cusa. Whatever weaknesses I may have as a historian of philosophy, I would be willing to claim one great strength, an ability to work up terrific enthusiasm for whichever philosopher I happen to be reading. Ask me who my favorite philosopher is, and I'm liable to just tell you that it's the one who I'm covering at the moment in this podcast. But it doesn't hurt when the figure in question reminds me of my real favorite philosopher, the great Encina, known in Latin as Avicenna, which has made it especially easy for me to warm to Nicholas of Cusa. That may seem surprising. What could this 15th century bishop from Germany have in common with a Muslim scientist, doctor, and philosopher of 11th century Persia? Well, for one thing, the quiet confidence that they had achieved greater heights even than Aristotle. But what I have in mind is something else, the strategy both use in offering their philosophical accounts of God. It's a strategy that is perhaps more familiar from the medieval Christian philosopher Anselm, who posited that God is that in which nothing greater can be conceived. On the basis of this single idea, Anselm went on to prove that God exists, this being his famous ontological argument, and then to derive all the usual divine attributes of God. Similarly, Avicenna introduced the idea of God as the necessary existent. After proving that there is indeed a necessary existent, he argued that such an existent would have to be unique, knowing, immaterial, powerful, generous, and so on. Nicholas of Cusa does the same thing, and repeatedly. In several of his major works, he puts forward a core idea and uses it to help us understand God, or rather, to help us realize that we do not understand him. Let's consider three such attempts from his fairly massive corpus of writings, starting with his most famous treatise, On Learned Ignorance, written in 1440. In this case, his fundamental idea is that God is the absolute maximum than which nothing can be greater. This is a pretty obvious reminiscence of Anselm, and to some extent Cusa proceeds as Anselm did, showing that the maximum must be one necessary and eternal. But he's not just trying to derive a series of epithets from the notion of maximality. Instead, he draws out a series of paradoxes, starting with the apparently contradictory claim that the absolute maximum would also be an absolute minimum. This is because both the absolute maximum and the absolute minimum are everything that they could possibly be. The maximum, because nothing could be greater than it, the minimum, because nothing can be less than it. For Anselm, God was that in which nothing greater can be conceived. Cusa goes on one better, or worse, God is that in which there is nothing greater and nothing lesser. The identity of maximum and minimum is a coincidence between opposites, the idea for which Cusa is probably most famous. His idea is that opposition breaks down at the level of God, the absolute maximum, something he tries to convey using mathematical analogies. He equates the maximum with the infinite, which is fairly plausible, given that infinity is that in which there can be nothing greater. He then shows how, at the scale of infinity, apparent oppositions collapse. A minimally curved line becomes indistinguishable from a straight line. A triangle whose angles are maximally wide, that is 180 degrees, also becomes a straight line. These analogies help us to see how things we normally take to be different from one another, even contradictory to one another, would come together and achieve identity in the absolute maximum, which is also the absolute minimum. On the one hand, both curvature and straightness would belong to the maximal line. On the other hand, neither would belong to it, insofar as being curved is taken to exclude being straight. A similar message is conveyed by a work written twenty years later, whose Latin title is De Pos est. Given that this treatise is about possibility, it's ironic that its title is almost impossible to translate. Pos est is an artificial term, coined by Kussa as a combination of posse and est, meaning to be possible and is. The idea then is that pos est combines what could be with what already is. This is meant to express the way that God is everything that he possibly could be. For Kussa, absolute possibility is possibility that is fully and permanently actual. This recalls the reasoning of unlearned ignorance, since it's another way of expressing the idea of God's being so maximal that nothing more could be added, and so minimal that nothing could be taken away. Kussa even reuses the example of the line, observing that a maximal line is the same as a minimal line, since this would be the line that could be neither greater nor less than it is. So there is no unrealized or unused possibility in God as there would be in a created thing. Even something as unchanging and impressive as the sun, as Kussa points out, could at least in principle be different. That would apply even more obviously to you and me. Regardless of your level of talent, there's a limitless range of things you could do, places you could be, and abilities you could acquire, and you can certainly not fulfill all these possibilities. Kussa calls to mind the US Army's advertising campaign that told prospective soldiers, be all that you can be, advice that upon closer inspection turns out to be metaphysically absurd. For some readers, me for instance, Kussa's argument also calls to mind the Avicenna conception of God as the necessary existent. For Avicenna, too, God is eternally everything that He can possibly be. This is the basis of his notorious claim that the universe is eternal. If God were to create the universe after not creating it, then He would have at first been only possibly creating, but God cannot have any unrealized possibilities. Kussa though draws a conclusion that Avicenna did not. For Kussa, if God actually realizes all possibility, then there can be nothing left out from God's nature. Every possibility there is must be not just present in God, but actually realized in God. Kussa expresses this by saying that all things are enfolded in God, present in Him, but as a unity, not a plurality. As we saw in Unlearned Ignorance, at the level of the divine, opposition and difference melt away to be replaced by identity. Only when the things in God emerge into the created universe will they be distinct from one another. They will no longer be fully and necessarily actual as they were in God, but contingent and subject to change. Just does God show Himself in a world that reveals its Creator? Or better, says Kussa, the unknowable God reveals Himself knowably to the world in imagery and symbolism. The result is admittedly an imperfect version of the reality that is compressed in God's perfection, but it is the only way that God can express His infinite nature in an outward form since otherwise He would just have to make a second God, and that would be absurd. God is, after all, already the full realization of what is possible. In 1461, one year after Des possesed, Kussa produced the ultimate statement of the coincidence of all things in God, Deli non aliud, meaning on, not other. Paging through it, you get the sense that it was written in response to complaints that his earlier works, though difficult and paradoxical, were not nearly difficult and paradoxical enough. Here's a typical passage, just to give you a flavor. Not other is not other, nor is it other than other, nor is it other in another. This for no other reason than that not other is not other, which cannot in any way be other, as if something were lacking to it as to an other. Because what is other is other than something, it lacks that than which it is other. But because not other is not other than anything, it does not lack anything, nor can any other anything exist outside of it. To which one might fairly respond, what? Actually though, what Kussa is saying here makes sense, or at least it makes as much sense as he intends it to. The fundamental idea is the same as what we've found in his other works. Nothing is missing from God, since he is the maximum, that is, already whatever can be. This is why Kussa says in the middle of the rather mystifying passage I just quoted that God cannot be other as if something were lacking to it. Again this is in contrast to the things God creates. The sky, which is Kussa's example, is different from or other than things that are not the sky, such as a giraffe, which is not Kussa's example. We know the sky, or a giraffe, or something else in the world by distinguishing it from everything else. That kind of knowledge cannot help us to understand God. Since God is the not-other, he has all the same things within himself, but of course as not-other from each other, as not yet distinguished, since they are enfolded together in him, no different from one another. Kussa compares this to the way that the distinct colors of a rainbow all emerge from the unity of sunlight. He argues that even nothingness is dependent on God and refracted from his unity, since in the created world, nothingness can be distinguished from the somethings that do exist. All of this might suggest that Kussa should be very liberal in the application of human language to God. Since the sky, giraffes, and even nothingness are all contained in him before coming forth from him, why not call God the sky, or a giraffe, or nothing? But this is not the moral Kussa takes from his own story. To the contrary, he emphasizes that any name we could give God would be inappropriate, since it would imply that God is other, that is other than anything else apart from the name we've used. If we called God a giraffe, this would not be entirely wrong, since the essence of giraffe is somehow contained within God's unity, but it would be mostly wrong, since the term giraffe really serves to distinguish giraffes from everything else. Thus Kussa says in On Not Other that God is not deprived of names, but rather prior to them. He applies this reasoning even to the transcendentals, the most general properties that, in medieval thinkers like Thomas Aquinas, were considered to apply to all creatures and to be realized most perfectly in God, like goodness, unity, and truth. For Kussa, even calling God goodness itself would be to damn him with faint praise, because goodness can be distinguished from other concepts. Goodness and the other transcendental properties only come after God, having been distinguished out of his utter lack of otherness. Or rather, they come out of him and through him and not just after him, as if they could have arisen spontaneously. These reflections represent the culmination of Kussa's longstanding interest in the limitations of human knowledge. He is powerfully influenced by such heroes of negative theology as the Pseudo-Dionysius and Maestro Eckhart, and follows their lead by saying that we reached the height of understanding by realizing most fully the failure of our understanding. At the beginning of On Learned Ignorance, he alludes to Socrates' claim to know only that he knew nothing, and agrees. The more that one knows that one is unknowing, the more learned one will be. He allows that we can make progress towards knowing God more fully, but only by successively stripping away descriptive language, or by realizing the inapplicability of different forms of cognition, whether sensation, imagination, or the mind. So long as we are still using the mind to grasp intelligible concepts, each of them a mere likeness of God, we are falling short of God's unintelligible, transcendent reality. Kussa compares this to the way a polygon grows ever closer to being a circle the more sides it has. To grasp God fully, to go from the many-sided polygon to the perfect circle, as it were, intellect would have to stop being itself. Like any created thing, intellect always has differentiation and unrealized possibility. Thus it can never become the maximum, never be so great that it cannot be greater. It goes without saying that this theory of going without saying has a long history. Kussa refers explicitly to Dionysius, but it was a more general Neoplatonic doctrine that God, or the One, outstrips intellect by transcending all description and differentiated thought. And Kussa is certainly an heir to the Neoplatonic tradition. This becomes clear, for example, in a work called On Conjectures, in a sequence of chapters describing a series of onenesses that track the standard levels of the Neoplatonic hierarchy — God, intellect, soul, then the physical world. But this same treatise betrays a more skeptical view of human knowledge than you could find in a thinker like Plotinus or Proclus. The title, On Conjectures, alludes to Kussa's claim that all human beliefs or affirmations about anything, not just God, are mere suppositions or conjectures. I said before that to use a word like giraffe is to distinguish something, namely a giraffe, from all the other things that are not giraffes. Kussa claims that this is all we can ever achieve using language and mental conceptions. We can only grasp that created things are different from one another, not the true natures or essences of the things in themselves. The fundamental reason for this, I think, is that essences are most fully themselves only when they are still enclosed within the unknowable unity of God. In Kussa's philosophy, there is no perfect intellect or intelligible world where our minds could grasp platonic forms. Instead, the essences of things express themselves only in created individuals, as imperfect likenesses of divine reality, which cannot offer us a basis for adequate knowledge of the essences. There is some debate as to how exactly universal natures exist in the created world, according to Kussa, since he sometimes sounds like a realist about these natures and sometimes seems to be saying that outside the mind there are only particular things. But there is a pretty clear passage on the question, at least clear by Kussa's standards, in Unlearned Ignorance, where he says that the infinity of God is contracted into progressively more specific instances, like the genus animal, then the species, giraffe, then the individual, aioatha. He adds that the peripatetics are right to say that there are no universals existing independently of things, only particulars really exist outside the mind. On the other hand, he says, universals have a certain universal being, which can be contracted by the particular. I take this to mean that Kussa is endorsing a realist position like that of Duns Scotus. There are no universals as such that somehow float around in extramental reality, but there is a real giraffe nature in aioatha that belongs only to her. There's a parallel here to the relation between God and the universe. Just as God's infinity is contracted into the limited form of the universe, which cannot realize all possibility the way He does, so the absolute nature of giraffe is contracted as the rather splendid but still more limited version of this nature that we find in aioatha. So here we have Kussa engaging with a theme familiar from medieval philosophy, the problem of universals. And as I've mentioned, he gives us strong echoes of medieval thinkers like Anselm, Avicenna, and Eckhart. The fact that he is writing around the middle of the 15th century shows us that approaches and themes thought to be typical of medieval thought were still viable at this period, and we'll be seeing more evidence of that as this series goes along. Appropriately enough though, Nicholas of Kussa reconciles the opposition so often drawn between medieval and renaissance philosophy. A glance at his biography shows that he can also be classed as an early northern humanist. Like other humanists from the north, he spent time studying in Italy, in his case in Padua, where he studied law, physics, and mathematics. He then returned to pursue theology at Cologne, but his work for the church took him to Constantinople in 1437. He brought back Greek manuscripts that still exist today in the archive at his home city of Chues. Of course the only thing more typical of humanists than collecting manuscripts was complaining about Aristotelian philosophy, and Kussa did that too. There's nothing in his works to anticipate the anti-scholastic diatribes of men like Juan Luis Vives or Thomas More, but he does pause in On Not Other to lament the way that Aristotle's philosophy fell short of grasping God's full transcendence. This is something he links to the limited resources of Aristotelian logic. To grasp the divine, we must go beyond reasoning. This means getting past the exclusive choice between affirmation and negation, instead embracing the coincidence of opposites, just as Dionysius managed to do. Depending on your philosophical tastes, you might find this to be an exhilarating or an alarming remark. It sounds like Kussa is rejecting the principle of non-contradiction, which is the basis of all reasoning, and not just for Aristotle. But in my view, that's not quite right. Saying that opposites collapse or are no longer applicable in the case of God is not the same as holding that two inconsistent propositions are both true. When Kussa speaks of the coincidence of opposites, he does not mean that two opposites both hold true of God while remaining opposed, as would a modern-day logician who introduces a third truth value for statements that are both true and false. This is called dialethism, and logical systems that allow for such statements are called para-consistent. Rather, Kussa means that the opposition breaks down altogether. This is more like what philosophers now call a category error, as when someone says that the number four is neither blue nor not blue because the whole concept of color doesn't apply to numbers. While the difference may seem rather technical, it's of considerable importance for understanding Kussa's negative theology. He keeps telling us that we cannot fully understand God. But why not, exactly? On the interpretation I'm suggesting, the problem is not that we are unable to believe two contradictory things at the same time, like by holding that the same thing is both straight and curved, even though straightness and curvature are mutually exclusive. Rather, what we are unable to do is fully to grasp how the straightness of the infinite line does not rule out its being curved. In favor of this reading is that it fits with what he says about other areas of Aristotelian logic like the theory of categories. Think again of the maximum and minimum and their identity in God. When explaining this, Kussa says, If you free maximum and minimum from quantity by mentally removing large and small, you will see clearly that maximum and minimum coincide. Later he tells us that the difference between substance and the other categories, like quality and quantity, is obliterated in God, because as the maximum he must contain them all. This is a clear rejection of Aristotelian logical tools, but it's a rejection that consists in simply deeming them inapplicable. Kussa is critical of other aspects of Aristotelian philosophy too. Like a number of thinkers in the generations to come, including Copernicus, Tilesio, and Cambanella, he distances himself from the medieval understanding of the cosmos. The imperfection of human knowledge is matched by that of the physical universe, which is, again, only a likeness of God's maximal perfection. Traditionally, the midpoint of an unmoving earth was taken to be the exact center of the spherical universe, but Kussa dismisses this, saying that the universe has no center or circumference apart from God himself. In fact, the cosmos is infinite, though this seems to mean only that it is in principle without fixed boundaries and could be increased in size by God without limit. Kussa is not saying that the universe is actually infinitely large. Furthermore, the earth is moving, which seems a striking anticipation of Copernicus, though Kussa does not say it is moving around the sun. In fact, his most insightful remark along these lines, and the most Copernican, concerns not the spatial arrangement of the cosmos, but the fact that up and down, or in astronomical terms, center and zenith are a matter of perspective. If we were at some spot in the heavens, we would think that it is the earth that is moving above us in the sky. Likewise, it is because we are on the earth that we do not realize it is moving. If Kussa's humanist interests and misgivings about Aristotelianism make it reasonable to think of him as a philosopher of the Northern Renaissance, then his political writings suggest that we could see him as an apostle of reform. His aim was to establish the maximum degree of agreement and harmony. As scholars have not been slow to note, this seems to be a political application of his characteristic approach in metaphysics. Kussa, the church lawyer and diplomat, was also Kussa the Neoplatonist, developing his own cluster of philosophical insights, incorporating all into one, reconciling poles of opinion and their contradictions. In the church, this meant working to resolve tensions between the papacy and the rest of the ecclesiastical hierarchy. According to a standard view of Kussa's career, he began as a staunch supporter of conciliarism, that is, the principle that agreements reached at a church council should be binding for the pope, but then he shifted towards equally staunch support for papal supremacy. This is probably an exaggeration, because even in his earlier conciliarist phase, he emphasized that the pope must be involved in reaching consensus at a council. So Kussa was clearly no Martin Luther. Any reform he hoped to see within the church should be just that, within the church, and imposed under the remit of papal authority. But equally, he wanted rulers to exercise authority within an institutional framework, not autocratically. Still more remarkable were Kussa's ideas for establishing consensus between Christians and adherents of other religions. Having been to Constantinople, he was shocked by the fall of the city to the Ottomans in 1453. In that same year, he turned his harmonizing mind to the question of interfaith dispute. In a dialogue called On the Peace of Faith, he drew a stunning inference from the radical negative theology developed in his other works. Since God is radically unknowable, no one religion can claim to know Him where others do not. We're all in the same boat, namely one sunken in ignorance, though if we've read Kussa, this could at least be learned ignorance. Thus the diversity of rituals masks an underlying unity, with all worshippers honoring the same God and in effect being members of a single religion. What seem to be clear disagreements are in fact just misunderstandings, as when Jews and Muslims think that the doctrine of the Trinity amounts to polytheism. Kussa is especially optimistic that the more enlightened members of all faiths could find common ground. He once again scores points with me by mentioning Avicenna as a particularly admirable Muslim philosopher who understood that the rewards promised in the Qur'an are spiritual and not physical in nature. It must be said that there are limits to Kussa's ecumenical broad-mindedness. He doesn't even mention atheism, which would obviously be beyond the pale for him, while pagan polytheists can only join in the happy family of the enlightened by accepting that there is a single ineffable God above their various divinities. Of more practical significance are his remarks about Jews, whom he takes to be especially stubborn. The only reassurance he offers here is that the Jews will not impede harmony, for they are few in number and will not be able to trouble the whole world by force of arms. It has also been observed that, while Kussa does not insist on an exclusivist claim to truth for Christianity as it existed in 15th century Europe, he does insist that the ideal religion he is envisioning—worship of a single, utterly transcendent God—is the only true one. Dispute and discord between the faiths is pointless, but only because all mundane religions fall short of the highest truth, which reigns supreme over them all. And of course it is entirely understandable that so many people have fallen short of that truth since it ultimately exceeds the grasp of humankind. This is perhaps the deepest sense in which Nicholas of Kussa prepares the way for what is to come in the next century and a half. His unrelenting focus on the inevitable weakness of human knowledge foreshadows Luther's doctrine of the unknown God, and also a more general trend toward skepticism that we'll be meeting in such figures as Michel de Montaigne and Francesco Sánchez. Kussa's talk of rainbows and infinite lines was not just a stylistic choice. Through the use of symbols and analogies, he sought to bring his readers as close as possible to the divine reality that lies beyond all mere possibility. It was a project he knew to be, like the universe itself, potentially endless. There is no end of symbolisms, he wrote, since no symbolism is so close that there cannot always be a closer one. The results were bound to be less than fully satisfying, but they were an improvement on what could be achieved through the straightforward language analyzed so meticulously by the university schoolmen. Kussa would have agreed wholeheartedly with the Russian symbolist poet Vyacheslav Ivanov, who said, Which seems like a good moment to stop talking, for now, but we're not yet done with Nicholas of Kussa. A thinker this complex and significant deserves a few more words devoted to him, and it's no coincidence that I've lined up a leading scholar of Renaissance philosophy to provide them, Paul Richard Bloom. That's next time here on the History of Philosophy Without Any Gaps.