 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 LMU in Munich. Online at www.historyofphilosophy.net. Today's episode, To Be or Not to Be – Debating Avicenna's Metaphysics Ever since I mentioned her in episode 139, my sister, the former trapeze artist, has been pestering me about working her into another episode. I resisted at first, but after all, she's family, or at least she would be if she existed. So let's welcome her back to the podcast. She's asked me to focus in particular on the plight of people like her, as she feels that our society has a real bias against non-existent people and does far too little to take their needs into account. Actually, there's a somewhat serious point here. In some areas of ethics, there arises a genuine difficulty about whether we could possibly have ethical obligations to people who don't exist. For instance, environmental ethicists wonder how it could be that we are perpetrating a moral wrong upon as yet non-existent future generations if we act in a way that will make the world a worse place for them to live. But in this episode, I will be returning to the more metaphysical question I discussed back in episode 139, What if any metaphysical status could non-existent things possibly have? It's a question that remains important, even if we show callous disregard to the huge population of non-existent people not living around us. For it will help us understand what it means for people like you and me, and all other things, to exist. As we saw in that earlier episode, Avicenna proposed a fundamental contrast that addresses this issue. He distinguished between the essence of a thing and that thing's existence. A thing's essence is what makes it the sort of thing that it is. Ayahuatha has the essence of a giraffe, whereas I have a human essence. What about my sister? Well, the temptation in her case is to say that she has a human essence, just like mine, but in her case this essence has not been realized, which is just to say that she doesn't exist. But as we saw, Avicenna takes a slightly different tack here, saying that my sister does exist, it's just that the sort of existence she has is mental, rather than concrete or external. In other words, she exists by virtue of being something we think about, even if she doesn't have reality outside our minds. Avicenna further points out that, for each item other than God, the essence leaves it open whether the thing in question exists. Giraffes and humans don't need to exist. That they do is the result of some cause that has made them exist. This is true even in the case of mental existence, since mentally existent things are made to exist by someone's thinking about them. So it is that giraffes and humans are merely possible or contingent beings. By contrast, God is a necessary existent, which means that God's essence guarantees his existence. In fact, Avicenna suggests that God's essence just is existence. That is, in a nutshell, the story I told you when we looked at Avicenna's metaphysics. One thing I didn't tell you then was that he seems to have been responding to an ongoing dispute among Muslim theologians. As usual, there was a dispute here between the members of the Mu'atazilite and Ash'arite schools of Qalam. It concerned the rather abstruse sounding question of whether the non-existent is a thing. The Mu'atazilites said yes, while the Ash'arites said no. Their disagreement concerned the very issue we've been discussing, though they often raised it in the context of interpreting certain verses of the Qur'an. In particular, the revelation states several times that when God wants a thing, He says to it, be, and it is. This verse applies the word thing to the item God has not yet created, and His command is addressed to this non-existing thing. Partially on the scriptural basis, Mu'atazilites argued that non-existent things, like my sister, are indeed things. But the Ash'arites rejected their talk of non-existing things as nonsensical. The Qalam debate helps to explain several things. First, my non-existent sister's strong preference for the Mu'atazilites. Second, Avicenna's new range of distinctions in metaphysics. The link between his discussion and that of the theologians is especially shown by the fact that he sometimes uses the neologism shay'iyya, or thingness, to express the idea of an essence. This bit of terminology may seem to indicate that he is signaling agreement with the Mu'atazilites, just as they would have non-existing things that can receive existence from God, so Avicenna would postulate essences that need to receive existence from a cause. On the other hand, Avicenna agrees with the Ash'arites that there are no non-existing things, because every contingent essence gets existence somehow, even if it is only mental existence. The theological background helps to explain something else too, which is the fact that philosophically-minded theologians after Avicenna were a little short of obsessed with this issue of essence and existence. That's the story I want to tell in this episode—the debates that raged, especially in the 12th and 13th centuries, over the distinction and how it should be applied to created things and to God. The cast of characters in this story include several figures familiar from the last few episodes. The founder of the illuminationist philosophy Suhrawadi, the great Ash'arite purveyor of arguments, Fakhradin Arazi, and the complex character we looked at last time, Nasir ad-Din At-Tuzi. The first two were contemporaries. Suhrawadi died in 1191, Arazi in 1210. We will start with the dispute between them, as Suhrawadi rejects Avicenna's distinction and Arazi defends it. Then we move on to several 13th century thinkers including At-Tuzi who further developed Avicenna's ideas. Before we get into the historical details though, let's think a little about the distinction for ourselves. At first glance, it seems eminently reasonable. Avicenna seems right in saying that it is one thing to understand what a giraffe is, to grasp its essence, and another thing to ascribe existence to a given giraffe like Hayawatha. It also looks like a good move to say that an existent that is necessary in itself would be one whose essence guarantees its existence, whether or not we agree with Avicenna that there actually is such a thing and that it is God. But upon further reflection, there's something rather odd about these essences, or thingnesses, Avicenna speaks about. What status could they possibly have independently of existence? Think again of my sister. Does she really hover in logical or metaphysical space, waiting in hope to see whether she will get to exist in concrete reality or remain only in our minds? Can we really make sense of the idea that there are not only giraffes and people, but essences of giraffes and essences of people which do not in themselves possess existence? Things aren't much clearer when it comes to existence itself. It seems straightforwardly true that asking what a thing is is different from asking whether it exists. Aristotle already made that point in one of his logical works. But Aristotle doesn't ever seem to use the idea of what we might call just plain existence, existence that remains the same no matter what essence it gets added to. Rather, he would think of the kind of being I have as fundamentally different from the kind of being we find in a giraffe. For the giraffe, being is not just to exist, but to be a giraffe. If we have the idea of being a human, being a giraffe, being God, and so on, why do we also need the more general and neutral notion of just plain existence? These were the issues at stake in the dispute between Suhrvadi and Fakhradin Ahrazi. We can start with Suhrvadi, since his position on Avicenna's metaphysical essence-existence distinction is simple, he doesn't like it. We saw when we looked at him that he was a trenchant critic of Avicenna, though in this case he may actually be directing his fire more at contemporary Avicenna thinkers like Ahrazi. Suhrvadi admits that we can draw a conceptual distinction between the essence of a thing and its existence, but that's all it is, a conceptual distinction. Suppose I am confronted with a giraffe at the zoo. I can think about what sort of thing she is, and thus consider her in terms of what Avicenna calls her essence, or I could just think that there is indeed something here in the giraffe enclosure, thus affirming that she exists. But the giraffe itself is not composed from two real things, her essence and her existence. She's just a giraffe, and she is the real thing there in the enclosure. Thus Suhrvadi rejects the notion that there are essences out there in reality that receive existence, like light switches waiting to be turned on. Nor is there any external reality that we could call existence. Rather, existence is merely a judgment made in the mind. He applies the same point to several other Avicenna notions, by the way, such as contingency. Again, contingency is not something real, but just our judging that a certain thing might not have existed. The same goes for relations, like the relation between brother and sister. These are all, as he puts it, things applied only by the mind. All this sounds pretty commonsensical. But if you aren't convinced, Suhrvadi has a nifty argument to persuade you that existence is nothing more than a mental judgment. Suppose that existence really were out there, really real. In that case, it must itself exist. But this way lies madness. If existence exists, then presumably its existence also exists, and so on. To say that a giraffe exists within existence that is real, and not only a judgment of the mind, is to commit oneself to an infinite regress of existences. Suhrvadi makes an equally persuasive argument against the idea of real essences more or less along the lines I've already suggested. If we posit that the essences that receive existence are real, then aren't we saying that these essences already exist? Just as a light switch must already exist if it is to be turned on, and a brother must exist before he can be pestered by his sister, so a real essence would need to exist in order to receive existence. But this seems to show that essences exist before they receive existence, which is clearly absurd. These are powerful objections to Evasena's distinction, at least if the distinction is understood as one that concerns the nature of things and not just the way we conceive of them. So it would take a powerful thinker, a master of argument, to respond to them adequately. Looks like a job for Fakhradin Arazi. Confronting Suhrvadi's nifty regress argument, which stated that existence would itself have to exist, Arazi reminds us of the original reason for distinguishing between essence and existence in things other than God. I cannot tell from considering the essence of such a thing whether it will exist or not. Nothing about giraffes requires that they exist. Thus, Hayahuatha's existence must be, as Arazi puts it following Evasena, additional to her essence. But this line of argument won't work for existence itself. We are not in doubt about whether existence exists. In fact, existence isn't even the sort of thing that exists or doesn't exist. Rather, things with essences exist or don't exist. So there is no reason to suppose that Hayahuatha's existence will require a further existence. Arazi not only fends off Suhrvadi's attack, he also argues positively for the real version of the distinction. All things that exist have something in common, namely the very fact that they exist. So existence is, Arazi says, shared equally by absolutely everything that there is, even God. Yet we don't only see single undifferentiated existence, rather we see lots of different kinds of things that exist. It must be the essences of these things that makes them distinct from one another. A giraffe and I are on equal footing in that we exist, but we have very different essences, which is why I don't lope across the savannah and Hayahuatha isn't hosting this podcast. Notice that according to what Arazi is saying here, we need essence and existence to be really distinct. We are trying to explain how it can be that things are different from one another and that difference is not the product of our mental judgments, so Suhrvadi must be wrong to say that essences are only figments of the mind. This line of argument has a further implication, which Arazi is not shy in embracing. I just said that according to him everything that there is has existence, even God. In respect of existing, God is no different, no better than I am. What makes him better than me, indeed infinitely better, is his essence, which among other things guarantees that he has existence, whereas I need something to cause me to exist. That's just what we mean when we say that God is a necessary existence, whereas I am a contingent thing. But existence in itself is always the same. It is the realization of an essence, whether necessarily or contingently. Arazi's great opponent in Avasena exegesis, Atuze, sees the situation differently. As we saw last time, he thinks that we can't really equate the way that God exists with the way that you or I exist. Whereas our essences leave it open whether we exist, God's essence actually is his existence. This means we can only say that there is a certain analogy to be drawn between the existence of created, contingent things and the existence of God. We can now perhaps see more clearly why Atuze would want to insist on this. Like Arazi, Atuze expresses full agreement with Avasena's real distinction between essence and existence. He would have no truck with Suhrvadi's skeptical position, which thinks of these as mere judgments of the mind. So, for him too, existence is really something out there in the world. But we just said that for Atuze, God's essence is his existence. If all existence is the same, as Arazi claims, then God's essence would have to be the same as any existence you care to choose, my existence for example. But this is obviously ridiculous, so there must be a difference between divine existence and created existence. Divine existence is the necessary being of God, whereas created existence is something that comes to an essence from an outside cause. Of course, Arazi would try to avoid this consequence by denying that God, or God's essence, is to be identified with existence itself. In fact, he goes so far as to say that God's essence causes him to exist. But there's a price to pay here, which is that the whole point of Avasena's theology was to say that God's existence has no cause. Atuze's position has the advantage of making God completely uncaused, even by his own essence. He can also ascribe a higher degree of simplicity to God. Since for Atuze, we cannot drive a wedge between God's essence and his existence. They are one and the same. Something really intriguing about all this, by the way, is that Arazi and Atuze are here fighting the same dispute as one we find in Latin medieval philosophy between Thomas Aquinas and Duns Scotus. In that case, the opening move was an analogy theory like that of Atuze. This was the position of Aquinas, which was then heavily criticized by Scotus, who thought that existence just means existence, even in God's case. As it is usually put in that context, Scotus, like Arazi, thought that existence is unifical. We will of course get into all that in future episodes on the Latin philosophers. For now, I'll just note the parallel and point out that it is no coincidence. Not that Aquinas and Scotus were reading Arazi and Atuze, or vice versa, but both disputes were triggered by an engagement with Avicenna, whose metaphysics leaves open both the analogical and unifical interpretations. It is no surprise that clever philosophers would take Avicenna's ideas in both directions. For now though, we're going to stay in the East, where we immediately observe something interesting among theologians of the Asharite persuasion. Of course, Arazi was an Asharite, and by far the most influential one since Agrazadi. So you might expect later Asharite thinkers to follow his lead on this central debate concerning essence and existence. But that's not what happened. Instead, the next significant thinker of this school parted company with him. This was Atir-at-din al-Abhari, who died in 1265, 60 years after Arazi. Al-Abhari was on board with Arazi's general project of using Avicenna ideas to uphold traditional Asharite positions in theology, but he was more concerned than Arazi to uphold one traditional Asharite position, the one I mentioned at the start of this episode, denying that the non-existent is a thing. For al-Abhari, Avicenna's and Arazi's enthusiastic embrace of the real distinction between essence and existence looks rather… well, he just comes out and says it. Mo'atazalite. After all, what are these contingent essences that need to receive existence, if not things that come to exist when God commands them to do so? Al-Abhari unhesitatingly rephrases the old Asharite view using the anachronistic language of Avicennism. His school's beloved founder, al-Ashari himself, was just saying that there is no real difference between essence and existence. For al-Abhari, the skeptical approach of the illuminationist Suhrawadi did a better job of capturing Asharite doctrine than the hard line Avicennism of his fellow Asharite Arazi. Following this line of thought, al-Abhari went on to accept At-Tuzi's position, which equated God's existence with his essence, and rejected Arazi's idea that existence is always the same, whether it belongs to God or creatures. Al-Abhari adds a clever new argument on this point by noting that everything real must be either necessary or contingent. That sounds reasonable, right? Now let's assume that Arazi is right to say that existence is real, and is always the same, whether it belongs to God or to created things. Which is it, then? Is the common existence shared by God and his creatures necessary or contingent? Neither option looks good. If existence is in itself contingent, then clearly it can't belong to God, the necessary existence. But if it is necessary, then it can't belong to contingent things, like us. Thus, we must distinguish between two varieties of existence, the necessary kind and the contingent kind, rather than thinking that it only comes in one flavor, as Arazi had supposed. These positions would be carried on by al-Abhari's student, a man named Najm al-Din Al-Khatibi Al-Khaswini. He died about a decade after his master in 1276. I mention Al-Khatibi now only because he will play a significant role in an episode coming your way soon, which is about logic in the later Eastern tradition. Al-Khatibi wrote a treatise on Avicennan logic, which became a standard textbook for many generations of students. But before turning to him and other contributors to logic, I want to stay with this theme of existence. There is a further position I haven't considered yet, which is the one upheld by philosophical mystics. Think back for a moment to Arazi's argument for the real distinction between essence and existence. He said that all things share existence in common, and are differentiated by essence. But as we know from looking at Ibn Adabi, philosophically-minded Sufis like him like to use the technical language of Avicennah to express the fundamental unity of all things. Thinkers who were that way inclined realized that they could now articulate Ibn Adabi's position in a new way. The essential differences between things will be unmasked as an illusion, an illusion that will not fool the mystic who grasps the oneness of being. In the next episode, we'll be looking at two great Sufis from the 13th century, one of them the famous Persian poet Rumi. So, join me to find out how the philosophical Sufis are like hot dog vendors. They make us one with everything. Here on the History of Philosophy, without any gaps.