 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. You can find me on Twitter and Twitter at K-9 at www.historyoffilosophy.net. Today's episode, Never Ending Story, the Eternity of the World. We saw in an earlier episode that medieval universities had a lot in common with today's universities. No wonder then that philosophers of the Middle Ages also had a lot in common with today's philosophers. A penchant for university intrigue, occasional despair over the behavior of their students, and an obsessive interest in particular philosophical issues. In some cases, those issues are the same—philosophy of mind, free will, logic. In others, the abiding concerns of the medieval have fallen out of fashion. One of those is the eternity of the universe. Immanuel Kant still took this problem seriously enough to discuss it in his Critique of Pure Reason, which poses an antinomy of pure reason concerning the infinity of time and space. Nowadays, the advance of modern science has taken it pretty firmly off the agenda. How different things were in the 13th century, when it seems that every significant thinker felt obligated to address the issue. But isn't this rather strange? After all, these philosophers were confident that they knew the right answer to the question of whether the universal is eternal. No, it isn't, because it was created with a beginning in time by God. So why spend so much time debating the issue? Besides, not much seems to be at stake here. If God is infinitely powerful, then surely he could have decided to create an eternal world. If he decided not to, but to create a temporally finite universe instead, then what philosophical significance could this possibly have? Quite a bit, as it turns out, and for two reasons. The first is that if you were making a list of points where Aristotle disagreed with Christian doctrine, this would appear at the very top. In several works, Aristotle made his belief in an eternal universe abundantly clear. In a painful irony, he even used it as a premise in proving the existence of God. So it was difficult, though as we'll see, not impossible, to deny that this represents a direct clash between Aristotelianism and Christianity. The second reason is that there is more here philosophically than meets the eye. Aristotle and many later philosophers had seen a firm link between eternity and necessity. For them, something that always exists cannot fail to exist. So asking whether the universe has always existed could seem tantamount to asking whether it had to exist, in which case God had no choice but to create it. By the same reasoning, if you could prove that the universe is not eternal, that would prove that it did not have to exist. And this would seem to imply that some cause beyond the universe was responsible for creating it. The happy result would be that you could prove the existence of a creating God by demonstrating the impossibility of the world's eternity. This helps to explain the proliferation of arguments for and against eternity, not only among Latin Christian thinkers but also the Greek and Arabic writing philosophers who influenced them. Appropriately enough, long-time listeners may have the feeling they've been hearing about this problem forever. The never-ending story goes back to late antiquity, when John Philoponus insisted that Plato's dialogue, the Timaeus, had to be read as denying the eternity of the world, a result much to his satisfaction given that he was a Christian who believed that the universe is created. Pagan Platonists like Proclus and Simplicius disagreed, insisting that Plato could be read as agreeing with Aristotle. The dispute passed into the Islamic world, where some relevant works of Proclus and Philoponus were translated into Arabic. Here, there was still some interest in reconciling Plato with Aristotle, but the chief issue came to be the compatibility of Greek thought with Islam and Judaism. In the Islamic sphere, most philosophers and theologians rejected the eternity thesis, often on the basis that an eternal world would need no creator. But the terms of the debate changed with Avicenna, who showed a way to affirm both the createdness and the eternity of the universe. He explained that if something is contingent, in other words in its own right capable either of existing or non-existing, then it would need an external cause to make it exist. Contingent things will exist only if God, the necessary existent, renders them existent. Yet for Avicenna, divine creation can be, and in fact must be, eternal, precisely because God is the necessary existent. He is necessary in all respects. So whatever He does, He does necessarily, and that includes causing the universe to exist. This whole theory was subjected to a searching critique in Al-Ghazali's Incoherence of the Philosophers, but that work was received into the Latin medieval tradition rather late. In another painful irony, the Latin Christians in fact saw Algazelle, as they called him, as a staunch ally of Avicenna, because he also wrote an exposition of Avicenna's ideas. This summary, called The Aims of the Philosophers, was translated into Latin much earlier, so it was taken to be an expression of Al-Ghazali's own views, whereas it was in fact mere preparatory groundwork for the critique of Avicenna presented in his Incoherence. Another influential text was The Guide of the Perplexed by the Jewish philosopher Maimonides. After a nuanced and balanced assessment of arguments for and against eternity, Maimonides concluded that philosophy cannot decide the issue. The universe might be eternal, or it might not. The only way we can know for sure would be if God were to reveal to us whether or not He created the world with a beginning in time, and this is exactly what He's done in the Bible. In Latin Christendom, the best-known stance on eternity is, as so often, that of Thomas Aquinas. He takes over Maimonides's solution of declaring a draw between the rational arguments for and against an eternal world, with the contest settled only by faith. He even follows Maimonides's inspired, if not particularly persuasive, attempt to show that Aristotle was not so convinced about eternity after all. Both of them refer to a passage from Aristotle's work on dialectic, the topics, which mentions this as a particularly difficult and debated question. Aquinas and Maimonides take this as a hint that Aristotle knew the question of eternity could not be resolved with complete certainty. With these two moves borrowed from Maimonides, Aquinas sought to take some of the heat out of the eternity debate. Neither the proponents nor the opponents of eternity could prove their case, and Aristotle's authority would be preserved in the bargain. The whole question could be removed from philosophy's to-do list as one whose resolution falls outside the remit of reason. Aquinas saw himself as occupying the reasonable middle ground. On the one hand, we're more strident Aristotelians who thought that philosophy does provide knockdown arguments in favor of eternity. It was clear that at least the Muslim thinkers Avicenna and Averroes fell into this category even if Aristotle himself didn't. On the other hand, there were fellow Christians who were equally convinced that they could prove that the world has existed for only a limited time. A good example of the latter approach can be found in Aquinas's fellow theologian at Paris, Bonaventure. In yet another irony, that's three so far in this episode if you're keeping track, Bonaventure shows more confidence in the power of reason to settle the issue than the supposedly far more rationalist Aquinas. In several of his writings, including his commentary on the sentences, Bonaventure argues that an eternal universe is impossible. Obviously, he does not want to suggest that God has insufficient power to create such a universe. Rather, the problem is on the side of created things. Bonaventure's central idea is simply to reject Avicenna's supposed insight that something could be both created and eternal. For Bonaventure, this is just a contradiction in terms. Creation means bringing something to be from nothing, in Latin ex nihilo. So if God genuinely creates the universe, then the universe must be preceded by nothingness. Bonaventure assumes that the philosophers who believed in eternity were not so stupid as to miss this point. Instead, their mistake was falsely supposing that God performs his works the way a created cause would, by bringing things to be from pre-existing matter or potentiality, like a carpenter who makes things out of wood, or fire which transforms fuel into flames. On this misconception, the universe would at least have to come from eternally pre-existent matter if not actually being eternal in the finished form that we see. To this core idea, Bonaventure adds a battery of further arguments. For one thing, he thinks that an infinite period of time cannot already have elapsed so as to reach the current instant. Also, even the philosophers would admit that it is impossible for an infinity of things to exist actually and all at the same time. But this is exactly what would happen if the universe were eternal. Just consider the souls of all the humans who have lived. If there have always been humans, and if human souls survived death, then by now we would have gotten to an infinite number of souls. Bonaventure connects this point to that other central dispute concerning philosophy in the 1260s and 70s, the unicity of the intellect. As we saw last time, there was intense debate in the late 13th century over Averroes's claim that all humans share only one single mind. Bonaventure observes that if this were true, Averroes could avoid admitting that there are an infinity of souls. There would only be one eternal mind for the whole human race rather than an infinity of rational souls continuing to exist after the deaths of their bodies. The two heretical doctrines of an eternal world and single intellect are thus the Hansel and Gretel of Averroism. They go astray hand in hand. If you're in the mood for one more irony, then you'll be glad to hear that consideration of the human species could also be used to argue in favor of the eternity of the universe. The point here has nothing to do with the survival of souls but the question of where humans come from. I won't get into details, since this is a podcast for the whole family, but we'll go so far as to tell you that people are generated by other people. Or as Aristotle put it in one of his pithier lines, man comes from man and the sun. But if each human has been generated by another human, there must be an endless string of humans all the way back into the past. So the world must be eternal. This argument is raised in a treatise about the eternity of the world ascribed to the so-called Latin Averroist, Sige of Brabant. Believe it or not, Sige actually raises the example of which comes first, the chicken or the egg? His answer is that every egg is preceded by a chicken to infinity. After more than 250 episodes, it's about time we got an answer to that question. Sige does not make so bold as to claim that the universe actually is eternal on this basis. He contends himself with presenting the argument and then saying, in one of those remarks that so infuriated his contemporaries and so intrigues modern day scholars, that he is simply presenting the opinion of Aristotle without endorsing it. Nonetheless, the treatise was sufficiently provocative that Henry of Ghent took up the argument in one of his disputed questions. He raises the possibility that there could be disastrous cataclysmic events after which species might need to be restarted, as it were. If all the chickens are wiped out in a flood, then we'll need to get some new eggs somewhere. The solution could lie in spontaneous generation, which for Aristotle and the medieval was a genuine phenomenon. But there's a problem, as Henry points out. Aristotle accepted that you can get things like flies and worms from mud or rotting flesh, but denied that more complex, so-called perfect animals can arise in this way. Avicenna was notorious for claiming that even humans can generate spontaneously, at least in theory, but few medieval thinkers agreed with him. In fact, this is one of the propositions that was condemned in 1277. So we are not going to escape the need for an infinite series of humans by supposing that humans can be spontaneously generated. And by the way, Henry adds, even if this were possible, the resulting infant would die from lack of care if no other humans were around. Of course, Henry doesn't draw the conclusion that there have always been humans. We're talking about a key member of the commission that drew up that 1277 condemnation, which also included the thesis that the universe is eternal. Instead, Henry says that God directly created the first members of each species among the higher animals. Their seed became the basis for all subsequent members of the species. If you want an omelet, you have to break a few eggs, but if you want an egg, God first has to create a chicken. Many of these same arguments reappear in Aquinas's various discussions of the eternity question. In addition to a short treatise devoted specifically to the problem, he takes it up in both the Summa Theologiae and Summa Contagentiles, as well as a set of disputed questions he wrote on the power of God. Throughout, he consistently adheres to the position I already described. Arguments for and against eternity are listed, but always found to fall short of providing real proof, though Aquinas allows that the arguments against eternity tend to be more persuasive. But he doesn't just point out the flaws in the various arguments. He shifts the terms of the debate by focusing on the question of whether any created universe could be eternal, rather than on the question of whether this universe we actually live in is eternal. This is well illustrated by his reaction to the infinite souls argument that so excited Bonaventure. Aquinas effectively dismisses it as irrelevant. He observes that God could have created a universe with no humans at all. The prospect of infinite human souls is no obstacle to God's creating an eternal world if it is in his power to create a world that has no souls in the first place. What about Bonaventure's more central claim that if God is to be a genuine creator, he must create out of nothing and therefore with a first moment in time? Never one to pass up an opportunity to make a subtle but crucial distinction, Aquinas points out that the phrase out of nothing is ambiguous. It could mean, as Bonaventure wants, from a situation where there was nothing, but it could also just mean not from something, in the sense that God needed no matter to form a world, in other words nothing whose potential for being a universe needed to be realized. Aquinas even goes so far as to cite Avicenna for the idea that eternal creation could be from nothing in this sense. He would also agree with Avicenna that when philosophers establish God as a principle who comes before all other things, the priority in question has to do with causation and not time. God is before the world because it depends on him, not because he existed before the world did. Aquinas is surprisingly sarcastic about Bonaventure's view. He remarks that some of his contemporaries have been amazingly sharp-eyed, able to see an inconsistency between createdness and eternity when even Augustine was unable to do so. Aquinas also points out that if God really could have created an eternal world, those who say otherwise are unintentionally disparaging his infinite power. While Aquinas is more severe in his rhetoric against Bonaventure and like-minded Christian theologians, he does also expose the flaws in philosophical arguments for eternity, including arguments found in Aristotle. One of the most prominent of these had been an appeal to the nature of the heavens. The heavens are, according to Aristotelian cosmology, made of indestructible stuff, the so-called fifth element. And many philosophers thought that if something cannot be destroyed, then neither can it be generated. Aquinas retains as much as he can of the Aristotelian view here by saying that the heavens are indeed immune to change, but they still depend on God for their very existence. Their permanent, unvarying nature presupposes that God has already brought them to be and given them this nature. Incidentally, Aquinas's teacher, Albert the Great, found a nifty way to press Aristotle's ideas about the fifth element into the service of creationism. Since the heavens are indeed incapable of being generated naturally, Albert says, they can only have come into existence by being created supernaturally. Aquinas's overall strategy obviously seeks to eliminate any direct clash between philosophy and Christian teaching. But there is a further insight underlying his position. He follows the late ancient thinker Boethius, the original one not Boethius of Dacia, in holding that God alone is eternal not in the sense of existing forever, but rather in that he is timeless. This means that an eternally created world would still fall short of God's sort of atemporal eternity. What makes the created world non-divine is not, in other words, the fact that it has only been around for a certain amount of time, it is that it is subject to time at all. And of course that it is dependent on God for its very existence. Neither of these features presuppose that the past existence of the universe is finite. Again, this tends to take the heat out of the debate. Whether the universe has always existed or not, its temporal existence shows its inferiority to the timeless God who created it. Given the bitterness with which Aquinas attacks his more radical Aristotelian contemporaries, and the fact that Boethius of Dacia is thought to belong to this group, it's a bit of a shock to read Boethius's own treatise on the eternity of the world. We discussed this text last time and asked whether it shows Boethius adopting a double truth theory, and we decided the answer is no. In fact, we can now see that Boethius's position is very close to that of Aquinas. He insists that the natural philosopher cannot pronounce with any finality on the question at hand precisely because this philosopher does not reckon with supernatural causes. Boethius's handling of individual arguments also recalls Aquinas's treatment of those same arguments. He too gives short shrift to Bonaventure's idea that genuine creation must mean bringing something to be after it was nothing, and he too says that the heavens immunity to generation and destruction has to do only with natural causes. Boethius even cites the same passage from the topics to prove that Aristotle considered the eternity question too difficult to resolve with any certainty. This is another nail in the coffin of any straightforward contrast between Aquinas and the so-called Latin Averroists, Boethius of Dacia and Sege of Brabant. As I've suggested before, Aquinas had real disagreements with Boethius and Sege, but he had more in common with them than he would gladly have admitted. He shared their admiration for Aristotelian science, and in a way was even more staunch in defense of that science. Unlike them, he refused to admit that proper philosophical reason can ever lead to incorrect conclusions. Nonetheless, he was, like Sege, prepared to place limitations on the scope of philosophy. Better to admit that an issue cannot be settled rationally than to admit an irreconcilable clash between philosophy and Christian doctrine, and with good reason. In the 13th century, if Aristotle was seen to be contending against religion, there was only going to be one winner. That concludes our look at the debates, recriminations, and personalities that dominate historians' view of Paris in the later 13th century, and I'd be the last to deny the historical or philosophical interest of these debates. They do, however, tend to obscure the fact that there were other interesting developments going on in the arts faculty in this period. We'll discover one of these developments next time, as we remind ourselves that however much time and energy the Scholastics poured into arguing over eternity, the intellect, and the nature of God, their minds rarely strayed far from the linguistic arts of the Trivium, namely logic, grammar, and rhetoric. We've spoken extensively about logic in previous episodes. Next time is the turn of grammar, as we examine the seminal contributions to philosophy of language made by the arts masters. As for rhetoric, I hope I don't need it to persuade you to join me next time, here on The History of Philosophy Without Any Gaps.