Medieval Philosophy

by Peter S. Adamson

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.

In the Islamic sphere most philosophers and theologians rejected the eternity thesis, often on the basis that an eternal world would need no creator.2 But the terms of the debate changed when Avicenna showed a way to affirm both the createdness and the eternity of the universe. He explained that if something is “contingent,” that is, in its own right capable either of existing or of not 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 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.

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, which is exactly what He has done in the Bible.

Both of them refer to a passage from Aristotle’s work on dialectical argumentation, 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 could not be resolved with complete certainty.

His 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 (ex nihilo).” If God genuinely creates something, then it must be preceded by nothingness. Bonaventure assumes that the philosophers who believed in eternity were not so stupid as to miss this point. Their mistake was falsely supposing that God performs His works the way a created cause would by bringing things to be from preexisting 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 preexistent 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. For another, even the Aristotelians 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 survive death, by now we would have gotten to an infinite number of souls. Bonaventure connects this point to that other central dispute concerning philoso...

unicity of the intellect. As we’ve just seen, there was intense debate in the late thirteenth century over Averroes’ claim that all humans share only one single mind. Bonaventure observes that if this were true, Averroes could avoid admitting that there is 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.

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 appears in a treatise about the eternity of the world ascribed to Siger of Brabant.5 Believe it or not, Siger 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. About time we got an answer to that question.

The solution could lie in spontaneous generation, which for Aristotle and the medievals 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.

He shifts the terms of the debate, focusing on the question of whether any created universe could be eternal rather than 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 (Aet. §12). 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?

It could mean, as Bonaventure wanted, “from a situation where there was nothing.” But it could also just mean “not from something (non ex aliquo),” 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 (ST 1 Q46 a1 repl obj 6). Aquinas even goes so far as to cite Avicenna for the idea that eternal creation could be “from nothing” in this sense.7 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 (Aet. §7).

The heavens are, according to Aristotelian cosmology, made of indestructible stuff, the so-called

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 by saying that the heavens are indeed immune to change, though they depend on God for their very existence. Their permanent, unvarying nature presupposes that God has already brought them to be and given them that very nature. Incidentally, Aquinas’ 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!

He follows Boethius (the late ancient one, not Boethius of Dacia) in holding that God alone is eternal in the special sense of being timeless. This means that an eternally created world would still fall short of God’s sort of atemporal eternity (Aet. §10; ST I Q46 a2 repl obj 5).10 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 requires the past existence of the universe to be 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.

Now we can see that Boethius’ position is in fact 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’ handling of individual arguments also recalls Aquinas’ 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 likewise comments that the heavens’ immunity to generation and destruction has to do only with natural causation. Boethius even cites that passage from the Topics to prove that Aristotle considered the eternity question too difficult to resolve with any certainty.

Aristotle states clearly that a science must establish universal truths, whereas grammar seems always to study a particular language.

While they admitted that many features of Latin or of any other language are “accidental,” they insisted that some features must be shared by all languages. It would be these “universal” features, which are essential to language as such, that are studied in grammar as a properly scientific enterprise.

When we say “giraffe,” we are signifying a substance only insofar as it has the particular quality, indeed the particularly wonderful quality, of being a giraffe.

The core idea of modism is that our ways of talking express our ways of thinking and that our ways of thinking in turn express the ways things are. Thus, we have a distinction between three types of “modes”: the modes of signification, which belong to language, the modes of understanding (modi intelligendi), which are the ways we grasp reality, and finally the modes of being (modi essendi).5 It’s vital to the modists that each thing out in the world really

does have multiple modes of being, since otherwise there would be no basis in reality for the various ways we can think and talk about a given thing.

These ways of speaking latch onto her “modes of being,” the various ways that she genuinely is.

The modist theory makes it sound as though our concepts somehow intervene between language and reality. Does a word like “giraffe” or “running” really signify Hiawatha, or only my thought of Hiawatha? This question was one of those disputed ones.6 Some authors insisted that words must refer to or “signify” concrete things like a particular giraffe. But many modists, such as Martin of Dacia, insisted that language does signify concepts, at least in the first instance. To signify something, you have to have it in mind. Your words express your thoughts rather than the thing itself. On the other hand, your concept is about the concrete thing in the world. This means that language can still signify the real thing via mental concepts. If I say “Here comes a giraffe,” what I am fundamentally doing is communicating a thought. But since my thought is itself about

something, namely the oncoming giraffe, my words do incidentally say something about the world.

How then does a mere sound (vox) come to acquire meaning? Only through an act of the mind, which imposes a certain meaning on a certain sound.8 This is what the grammarians call the ratio significandi or “signifying relation.”

The grammatical differences are there to mark further acts of the intellect, whose various modes of understanding

correlate with cases and parts of speech. When I mean to refer to the pain in my toe, I use a noun; when I describe how it is making my toe feel, I use the adjective; when I want to let you know that you’re standing on my foot, I use the interjection. Once the “mode of understanding” is marked at the level of language, we have what the grammarians called a pars orationis, a word as it would actually appear in a real sentence. The grammarians like to say that with this sort of expression we are signifying one thing as another, as when I signify a pain as something that is hurting me right now. When all goes well, the mode of signification reveals a mode of understanding that actually fits the way the world is, in other words, grasps a real thing under one of its modes of being. My toe really hurts; the thing out there really is a giraffe, and it really is seeing something, or being seen, or standing on my foot. But sometimes all does not go well. There’s a difference between saying something meaningful and saying something true.

More puzzling for the modists were cases where language doesn’t look as if it even could correspond to the world under any mode of being. To what does the word “nothing” refer, or the word “matter,” assuming, as the medievals did, that matter is pure potentiality? Again, the role of mental concepts could come to the rescue here. By negating concepts that do refer to reality, the mind is capable of forming notions of potentiality, nothingness, or privation, even though no such absences really exist outside the mind.9 This solution could also be used to handle “empty” words like “centaur” or “chimera.” These signify concepts that are only figments of the mind with no correlate outside in real being.10 Then, there are the linguistic expressions that don’t even pretend to signify anything, those words like “if” and “not.”

The grammarians tended to see them as serving a merely auxiliary function. It was even claimed that they are properly speaking “not part of language.”

But the grammarians go further, emphasizing that speaker and listener are engaged in a cooperative enterprise. The speaker tries to make his meaning clear and the listener seeks an interpretation of his words that will make

sense. This is one reason our attempts to communicate aren’t tripped up by the many ambiguities found in natural languages.

While some were prepared to admit that whiteness is something out there in the world, Boethius of Dacia was reluctant to do so. For him this is another case where a word refers to a mental concept, in this case an abstract generalization produced by the mind based on experiences of particular white things.

Radulphus’ solution is classic modism. It distinguishes between the levels of language, concept, and reality while positing an intimate connection between the three levels. Of course, that connection isn’t always present. We do talk about chimeras and even say things that are meaningless or (horror of horrors) ungrammatical. But the whole point of modism is to reveal how the connections work when things go well. Still, we can see easily how the tools of speculative grammar could be turned in a more skeptical direction. If

you think that universals have no basis in reality, you might argue that phrases like “every human” express only modes of understanding and not modes of being. You might emphasize the arbitrariness of language and of the mind.

This looks like grist for the mill of the theological reading. In our fallen state, we are incapable

of listening to the call of reason and giving sex its proper value.12 Where we should feel natural desire, we are carried away by unrestrained lust. If Reason really is speaking for Jean, then she is calling us not to act like the hero of courtly love romance but like the man Augustine was striving to be: one who, as Reason says, loves all humans generally rather than becoming obsessed with just one particular human. The Lover’s failure to do so is meant not to be inevitable but instructive.

Like the Platonist authors of the supposed “school of Chartres” (Chapter 14), Reason speaks of the surface of a myth as a “covering (integumentum)” that conceals deeper philosophical meaning (109).

His fixation on improper language would go hand in hand with his own improper obsession with private pleasure. Where he should love all humankind and appreciate nature as God’s creation, the Lover thinks only of his rose. In other words his problem is that he is not a philosopher.

Amidst all this cosmic harmony it is only humans who violate the correct order with their sexual immoderation.

On this point Henry agrees with Thomas Aquinas that theology is a science, and one with an intimate relationship with philosophy.

Philosophy can thus be very useful, as long as one has already accepted the truths of the Christian faith in advance (116). This is an important constraint, because philosophy on its own is liable to reach conclusions that would be overturned from the perspective of theology. One reason for this is that philosophers consider only what Henry calls “proximate” causes, which may be trumped by the ultimate cause that is God.

Still, philosophy can help us understand religious doctrines more fully. As far as Henry is concerned, it is better to grasp something with certainty on the basis of reason than without certainty on the basis of faith

Like Aquinas, then, Henry situates theology within a system inspired by Aristotle in which higher sciences provide the principles for lower sciences, with theology at the top.

Still, metaphysics is part of human philosophy, which studies things in themselves, whereas theology studies things in relation to their divine source (55). That makes theology, not metaphysics, the highest and most authoritative of all sciences. Here Henry disagrees with Aquinas, who had suggested that theology is subordinated to an even higher science, namely that of God Himself. This proposal prompts a scathing response from Henry. He remarks that Aquinas apparently didn’t understand what it means for one science to be subordinate to another (85). Divine knowledge is not made up of discursive arguments that can provide premises to be used in the demonstrations of a lower science. So it is a crass mistake to integrate God’s understanding of Himself into the scientific hierarchy.

He could go for an Aristotelian model of knowledge according to which we

use our senses to learn about the world around us and then abstract our concepts from these experiences. Or he could adopt a more Augustinian theory on which God illuminates the mind. Other thirteenth-century thinkers had emphasized one of these two accounts without entirely rejecting the other, with Bonaventure highlighting the need for illumination, Aquinas the contribution of sensation.

In some cases we can immediately arrive at such a concept without having to depend on sensation, as with a fundamental or primary idea like “being” or “thing.”

But also, if concepts are “words,” this makes it easier to see how thoughts connect to language. When you utter a word like “giraffe,” you are simply expressing the concept or mental “word” of giraffe that is in your mind. As we form mental words, we are, of course, trying to understand the nature of the things we are encountering, to grasp the very essence that makes something a giraffe. That isn’t something we can achieve simply by forming a concept, though. Since we are limited

creatures, our ability to apprehend natures is also limited. Henry compares the initial concepts we form to seeing a book in dim light, such that you can tell there are letters written there but not what they say.8 How then can we see things in, so to speak, the full light of day? This is the cue for Henry to turn to the second option, the Augustinian illumination theory. The human mind can achieve certain understanding of true essences with help from God.

Like Plato, he asserts that true knowledge can be had only in the light of perfect exemplars, which God created as models for the things we find around us in the physical universe. These exemplars are the “very natures and essences of the things.”9 By aligning our initial concepts with them, we can avoid all error and guarantee a successful end to the scientific enterprise.