Medieval Philosophy

by Peter S. Adamson

Unlike many medieval thinkers, he’s confident that we can in fact use language to refer to God (§21). He suggests that this may be achieved through a relation or “analogy” between God and the things He creates (§40), an idea we will see again in later thirteenth-century thought

The word at the heart of his natural philosophy is “species.” This is potentially confusing, because we’ve so often seen the word in the context of logic, as when species is contrasted with genus. Originally, though, the Latin word species means the outward appearance of something, and that’s somewhat closer to the way Bacon is using it. A good English rendering might be “effect.” Bacon’s idea is that natural things influence the world around them by imposing a “species” or “effect” on other things; hence his official definition of species as “the first effect of any natural agent” (§1.1, 28–9). A basic example might be fire, which affects nearby bodies by giving them the species of heat.

Bacon denies that, in producing species, things are somehow sending out parts of themselves which would be lost, like the sheets of atoms thrown off things in the visual theory of ancient atomism. Strictly speaking, species are not “emitted” at all (§1.3, 8–9). Instead, the influence of the natural agent causes a potentiality to be realized in the thing it affects (§1.3, 51–2).

It was, of course, standard medical theory that human and other organic bodies are made up of the humors, but Bacon is unusual in applying the scheme to non-organic things like minerals and metals.

Despite his flirtations with the occult, he has (like Robert Grosseteste, but with considerably more plausibility) been hailed as a pioneer in experimental science, a worthy forerunner to a man who shared both his name and his scientific attitude, the Renaissance thinker Francis Bacon.

The traditional answer would be yes, and the traditional basis for that answer would be the contrast between two of the era’s greatest thinkers: Bonaventure and

Thomas Aquinas. Bonaventure, a Franciscan, stands for a mystically tinged theology and skepticism concerning the secular offerings of philosophy. He steers by the star of Augustine, about whom he wrote, “No question has been propounded by the masters whose solution may not be found in the works of this Doctor.”2 Aquinas, a Dominican, represents the Aristotelian side of the debate, aware that theology is needed to complete the teachings found in the philosophers but eager to make full use of those teachings nonetheless. The contrast is epitomized by their rival conceptions of human knowledge. Bonaventure promotes Augustine’s idea, already revived by Robert Grosseteste, that human knowledge is possible only thanks to an illumination granted by God. Aquinas instead places his trust in our senses, following the Aristotelian line that we can abstract general knowledge of the world from our perceptual experiences.

Hugh did not consider the so-called “mechanical” arts beneath his notice and neither does Bonaventure, who sketches the purpose of such activities as farming, hunting,

and weaving (§2). Even these arts are a “light” given to us by God, though merely an “external” light, because they involve us with things outside ourselves. Every human enjoys the gift of two further lights within his or her own nature: the “lower” light of sensation and the “inner” light of philosophy. Crowning them all is the light of grace, which offers salvation. But all four lights are given by God (§1). Bonaventure also detects images of the divine within all these arts. When a blacksmith makes a horseshoe, he tries to fashion something that represents as well as possible the idea of a horseshoe in his mind, in an unwitting imitation of God’s creation of things through the divine Word (§12). Even when we look at something, the visual image we receive is a so-called “similitude” begotten by whatever it is we’re seeing, just as God the Son is begotten by God the Father (§8). Parallels of the same sort are discovered in the various philosophical sciences. When he comes to logic, Bonaventure takes his cue from the Aristotelian account of words as representing mental concepts. He points out that linguistic signs make our ideas known in physical form, that is, in the sounds we make when we talk. Just so was the divine made known in the Incarnation (§16).

Far from being in tension with theology, the other arts are to be used by theology. This too can be traced back to Hugh of Saint Victor, who admonished his youthful students to “learn everything,” because all knowledge may help in understanding Scripture.

the causes or “reasons” for things that we find in matter are mere images of what Bonaventure calls “ideal reasons (rationes ideales),” which are found in God Himself (§20). We might go so far as to say that created things are nothing more than signs of divine reality, much as a linguistic sign represents the meaning intended by the person who uses the sign.

To study the world for its own sake is to concentrate on the created image at the expense of the divine reality.6

Instead, it asks whether it is generally the case that humans attain certainty through illumination from the divine exemplars.

Instead I’ll reduce them to two groups of considerations, having do, on the one hand, with the things that we know and, on the other hand, with our situation as knowers. Concerning the objects that we know, Bonaventure sounds like many a Platonist when he demands that nothing can really be known unless it is unchanging (118, 121). There is a hint of Aristotle here too. He stipulated that only necessary and eternal truths are truly knowable. For the Platonists, for Aristotle, and now for Bonaventure, we cannot take ourselves to know that something is true if it may stop being true at some point. Thus, created things in

the sensible world cannot be the true objects of our knowledge, because none of them endures forever. And what about us as knowers? Here Bonaventure and the sources he has quoted argue that our minds are simply too limited to achieve genuine knowledge by their own power. How can a limited mind come to grasp the unlimited (122), as when we come to understand number, which is potentially infinite? How can creatures who are fallible by nature enjoy knowledge, which is infallible? The mismatch between imperfect knowers and the perfection of knowledge can be overcome only if some other perfect principle is involved, and that principle is provided by divine illumination (121). We can bring the whole line of argument together by referring to the key word in the title of Bonaventure’s disputed question: how is it that humans achieve certainty? Only if there is no hint of unreliability on either side, in the subject or in the object. The things we know must be guaranteed to be permanently knowable, and our act of knowing must be guaranteed to grasp the truth about those things. Speaking of truth, Bonaventure repeats an argument from Augustine to the effect that God must be involved in our knowledge, since knowledge is always true and God is nothing other than the Truth itself (115). We can see here that the theory of illumination connects to the now familiar doctrine of the transcendentals. God is the source of being and truth for all created things, so when we know them, we are in...

But we need to be careful here. All the talk of unchanging objects may lead us to think that the divine exemplars are the very things we know, insofar as we get to know anything. As I’ve already said, though, Bonaventure insists otherwise. In the “response” at the center of the disputed question, he explains that we never know the divine exemplars, at least not in this life. Rather, we know created things as images of the exemplars. The talk of “illumination” is not meant to suggest that we are beholding God’s ideas like lights flashing in our mind’s eye. Rather we are knowing about created things in the light of the exemplars. The metaphor does not have God playing the role of a brilliant lamp into which we are staring, but of a lamp that is making other things visible so that we can see them. Bonaventure describes it with somewhat less metaphorical (but not entirely literal) language by saying that the exemplars serve as rules or standards (regulae) for the things we know (134). When we know that giraffes are ruminants, it’s as if we are implicitly comparing created giraffes to the divine idea of a giraffe, with the comparison allowing for certain knowledge rather than mere belief. The exemplars provide a perfect standard in the light of which we can judge. But something else is needed too. We must enjoy an encounter with some actual created giraffes, or there will be nothing for the divine light to illuminate. To this extent, like Grosseteste before him, Bonaventure cou...

Pecham notes that some of our concepts seem to be so immediate that we grasp them with no prompting from sense perception. The transcendentals would be such primary concepts. They therefore constitute an exception to the general rule that sensation is needed as a second source for knowledge alongside the divine exemplars.8 Pecham and Matthew of Aquasparta are also somewhat more careful in distinguishing between the grasp of simple concepts and whole propositions, the difference between understanding plain old giraffe and understanding a complex truth like “Giraffes are ruminants.” It seems that Grosseteste mostly had propositions in mind when he first started to develop the illumination theory. But by the time we get to Bonaventure and especially his followers, we are seeing the theory applied to both kinds of knowledge.

In this work Bonaventure makes many of the same points we’ve already discussed, for instance that created things are mere signs or traces (vestigia) of God (§2.1). The illumination theory also emerges at several points, as when Bonaventure says that God provides the rule by which we understand things, as if we make our judgments in accordance with immutable laws (§2.9),

or that since the human mind is changeable, it cannot know unchanging things without help (§3.3).

Ultimately Bonaventure is true to his Franciscan roots. For all his deft scholastic distinctions and his care to retain at least some of Aristotle’s teachings, philosophical knowledge is not his goal. Or rather, even if philosophical knowledge is his goal, it is not his final goal. Just as bodies and the mind are a kind of “ladder” to God (§1.2), a stairway to heaven, if

you will, the real meaning of philosophy is found when we discover that it too is a trace of the divine.

It’s above all here that he sets forth

some of his most original ideas, in the form of a critique aimed at Aristotelian views on the human soul. Here he’s carrying on a discussion that began in earlier thirteenth-century writings, concerning Aristotle’s definition of soul as the form of the body (see Chapter 24). In addition to the obvious difficulty that this could imply the soul’s dependence on the body, thus precluding its immortality, there was a puzzle about whether we can really understand humans to have only one form. Olivi’s contemporary Thomas Aquinas insisted that this is exactly what we should think. For Aquinas, the person is a single substance whose unity is provided by one and only one form, which is the person’s soul.

In order to explain how we humans can have such radically different powers, ranging from the lowly processes of nutrition to the exalted exercise of freedom and intellective thought, we should simply give up on the idea that each of us has one and only one form. Instead,

we possess a plurality of forms which give us a variety of capacities. Taken in its entirety, the human soul is simply an aggregate or collection of these different powers, all of them parts of a greater whole.

Instead, the soul is already a substance in its own right, with no dependence on the body at all. It does have matter, but the soul’s matter is incorporeal or “spiritual,” an idea used by Philip the Chancellor and Olivi’s fellow Franciscans Roger Bacon and Bonaventure. The soul’s matter unifies the multiple powers and forms that make up the single soul. The physical body too is included in the unified person. The lower soul is responsible for sensation and other tasks realized through the body, so we should admit that it is unified with the body it is using. The higher, rational soul lacks this

sort of connection to the body, but it is unified to the lower soul because the two souls share the same spiritual matter. Thus, even though the rational soul has no direct relationship to (never mind dependence on) the body, it forms a unity with the body indirectly or “transitively.” It is unified to the lower soul and the lower soul is in turn unified to the body.6 All of this is, I think, profoundly un-Aristotelian, which, of course, would bother Olivi not one little bit. In Aristotle’s writings on the soul we are told that it is the human person who performs the various psychological functions through the soul. Your soul is not a separate thing in its own right, never mind a separate thing whose most important part is only indirectly related to your body. By contrast, Olivi insists that the soul itself is the subject of our most important psychological activities. This is evident from his treatment of free will. Here we’re again anticipating a central dispute in later medieval philosophy, which is usually framed as a clash between two ways of explaining free actions, called by modern scholars “intellectualism” and “voluntarism.” As we saw, the basic idea of the intellectualist position is that human choice is prompted by some belief or understanding of the best thing to do. The voluntarist, by contrast, wants to say that a free choice consists in a sheer act of the will. Our choices may somehow be influenced by our beliefs but ultimately the explanatory buck stops wit...

The will is not passive with respect to beliefs or reason, but active. It moves itself rather than being moved by another part of the soul. There’s a connection

here to Olivi’s ideas about the higher soul. One of his main purposes in isolating the thinking and willing soul from the body is that bodies are incapable of this kind of self-initiating activity which is not moved by anything else. A stone can’t just get up and roll on its own. It needs some other cause to set it in motion. By contrast, humans are self-movers, and according to Olivi, if we are searching for the source of this spontaneous action, we should look to the will’s irreducible capacity for choice, not to reason’s ability to perceive things as choiceworthy.

But philosophers talking about perception usually focus on the case of vision, so let’s do the same. In honor of the hero of this chapter, please imagine that you’re seeing a green olive. Bacon’s explanation of how the visual experience occurs is that a green object will affect the air surrounding it by imparting the species of green to it. This species is then passed on or “multiplied” through one part of the air after another. When the effect gets to the air touching your eye, the species is received in your eye and this causes you to see green.

But Peter Olivi thinks it suffers from two fatal weaknesses.8 The first is that, whatever it means for the so-called “species” of green to turn up in your eye, the presence of that species in the eye cannot be identical with, or even give rise to, a perception in your soul. Immaterial things can certainly influence physical things, as when your soul commands your hand to reach out to take an olive out of a bowl, but the reverse is not the case. Bodies cannot affect anything incorporeal. That’s the first problem with the species theory, one that would, of course, only impress someone who shares Olivi’s assumption that bodily states cannot affect an immaterial soul.

What Olivi is proposing here is an early version of what is nowadays called “direct realism,” a theory of perception that avoids invoking representations

of the objects of perception in favor of the claim that we perceive things without any intermediary.

What really bothers him about the species theory is that it makes us passive as perceivers, much as the intellectualist theory of choice made the will passive. Against this Olivi insists that perception is no more passive than the will. To perceive an olive I must actively do something: I must attend or pay attention to the olive. In fact, Olivi even uses the word attencio to describe the phenomenon.9 He also uses the evocative language of “imbibing” or “drinking in” what is perceived. Less metaphorically, but still somewhat mysteriously, he speaks of the soul’s aspectus, a kind of orientation or direction of focus that we bring to bear on things when we attend to them.10 Olivi gives an illustration of his point that is not unlike Plotinus’ case of the mind wandering when one tries to read. He asks us to consider someone sleeping with his eyes open. If there is light in the room, the sleeper’s eyes should be physically affected by his surroundings, just as they are when he is awake. So the sleeping person should see, if seeing is a purely passive process, as the species theory demands. But in fact, sleeping people don’t see anything, because their souls are at rest

and not attending to the things around them. I should note that Olivi doesn’t rule out that the eyes are somehow affected by their surroundings. To the contrary, he admits that they are, as is clear from Roger Bacon’s observation that we continue to see afterimages of bright lights after we stop looking at them. Olivi’s claim is rather that the physical effects in the eyes or other sense organs do not cause sensation. The soul perceives simply by attending to the things to which it has access. And there’s another possible misunderstanding we should avoid. Olivi is not claiming that we have to be giving something our full and undivided attention in order to perceive it. If you’re reading this book while a bowl of olives is on the table in front of you, you may be seeing the bowl without, as we might say, really paying attention to it. But according to Olivi this shows merely that the soul’s active attention comes in degrees. It can be entirely absent, as in the sleeping case, or it can consist in the kind of basic, background awareness of our surroundings that we have as we go about our waking lives. He would no doubt have loved the example of overhearing your name at a party, since it suggests that your soul is actively monitoring the environment all the time, always ready to give particularly close attention to whatever seems salient and interesting. Who has the better of the debate between Olivi and the representationalist? It’s hard to say, given that philosophers of pe...

Why can’t I see behind my head, if it is my soul’s attention that makes the difference and not the way the objects in front of me are affecting my eyes? Olivi’s solution would seem to be that our bodies do restrict the scope of our awareness in this life. Remember that the power of sense is in the lower soul, and thus tied to the body. In the afterlife we will not be so restricted, but will have a more general and unimpeded apprehension of things.

The mendicants claimed to be devoted to the care of the poor and would donate their worldly wealth to charity upon joining the order. All well and good, argued William and Gerard, but really effective assistance to the poor requires careful acquisition and management of resources. Charity is a lifelong calling, not something best shown with one spectacular act of self-abnegation. From this point of view, the development of the Franciscan Order to a well-established organization with considerable material assets was advantageous; but it was hypocritical for the friars to present themselves as rootless beggars at the same time. Another accusation was that the mendicant ethos was effectively a revival of the ancient Manichean heresy, which despised the things of the physical world. Humility is well and good, but the refusal to own any possessions at all constituted a degradation of the

human, who is after all unique among creatures as being fashioned in the image of God.

In the shorter run, the distinction between use and ownership presented a tempting target for secular critics. They argued that we may be able to apply the contrast to things like buildings and books, but not food and other items that are consumed in being used. In theory every time they had dinner, the friars were “using” food that belonged to someone else. But are you really only “using” something you don’t own if you destroy it in the process?

He highlighted the spiritual dangers of wealth, which draws us away from God and towards the things of the body. Voluntary poverty is the most powerful way of taming one’s desires, comparable to the vow of chastity undertaken in the monastic life. And if, as everyone admits, perfect chastity is better than lesser forms of sexual restraint, how can one deny that perfect poverty is best? Ownership is inextricably bound to sin. In fact, it became a feature of human life only after the fall from grace. In a state of perfected nature things would be shared by all.

By then secular masters like Henry of Ghent and Godfrey of Fontaines had chipped away at Bonaventure’s carefully laid legal justifications.11 If the mendicants are like minors or the insane, they can’t even legally receive gifts, which makes it impossible to give them alms. Aristotle’s authority could also be invoked against the mendicants, since he was

clearly against the ethos of poverty. His Ethics emphasizes the need for wealth as a component of the good life, if only because it enables us to show generosity towards others. As for the Franciscans’ claim that they could coherently abandon all ownership of goods, the secular masters responded that this is, in fact, impossible. Everyone must at least be guaranteed the basic means of subsistence. This is why one may be excused for stealing food if one is starving to death. Godfrey of Fontaines introduces the idea of “natural ownership,” a kind of inalienable right so fundamental that one cannot even give it away voluntarily. I’d like to dwell for a moment on how extraordinary this is: we’re seeing the emergence of the notion of a basic economic right. Of course, that is not to say that Godfrey is developing a systematic theory of human rights, but it is a significant step along the way to such theories, something we would scarcely have expected to find within the context of a politicized debate over religious asceticism. The secular arguments damaged the Franciscan case, but the friars’ cause was arguably harmed still more by poverty zealots among their number who demanded a more radical approach than the one defended by Bonaventure. The main protagonist here is Peter Olivi, who set the theme of poverty within an apocalyptic view of history.12 For him, Francis of Assisi was the “angel of the sixth seal” from the Book of Revelation, whose role was to usher in a new and fin...

since it allowed them to serve as moral exemplars. Like Bonaventure, Olivi vigorously refuted criticisms of mendicancy. But he also turned his fire against other Franciscans, who among other things had argued that renunciation of ownersh...

Yet when it came to the actual practice of what was called “poor use (usus pauper),” Olivi showed flexibility. He understood that it would be impossible to give general rules covering all possible circumstances, and encouraged Franciscans to consult their own conscience when considering difficult cases. Here we may detect a connection to the idea put forward by Bonaventure and others, that an in-dwelling sense of morality called conscience or synderesis plays a fundamental role in ethical life (Chapter 26).

By now you probably feel you have a good understanding of what philosophy was like in the thirteenth century. It was often highly technical, marked as it was by the use of new logical tools. Though theology was the highest science, philosophical problems were often pursued with less reference to religious doctrine than to Aristotle and other works made newly available in Latin translation. And, of course, it was undertaken at the newly founded universities, by men who were usually clerics and always wrote in Latin.

Still, mysticism did offer unprecedented opportunities for literary achievement in the thirteenth century, and it’s no accident that the medieval women whose words and ideas have survived were usually mystics or spiritual authorities. A leading scholar of medieval mysticism, Bernard McGinn, has spoken of a “democraticization” of Christianity that began in the early thirteenth century, in which access to God was gradually conceded to ordinary believers as well as the powerful representatives of the Church.

After being warned that her daring book may wind up being burned, she receives a vision from God who assures her that “no one can burn the truth” and that Mechthild’s book symbolizes the Trinity. The physical

parchment is the incarnation of the Son, the written words the divinity of the Father, the spoken words the Holy Spirit.

There is something of a paradox here, with our authors claiming special access to God, yet speaking constantly of their utter estrangement from him. The paradox may be resolved by noting the fleeting nature of mystical experience and the inability of the mystics to enjoy that experience on command. When they sit down to write, they are recalling moments of exalted intimacy, having come back down to earth. It’s this that makes their use of the motifs of courtly love philosophical. The talk of minne is among other things a way of articulating the experience of the special kind of knowledge afforded to the mystic, followed by the sudden loss of that knowledge.

In moving on to love Hadewijch is thus leaving behind language as well