Medieval Philosophy – Prof. Dr. Robert C. Koons http://www.utexas.edu/cola/depts/philosophy/faculty/koons/phl349/syllabus.htm

Lecture # 3: Plato, Plotinus, Pseudo-Dionysius, John Scotus Eriugena I. Plato’s Timaeus As discussed above, Plato’s dialogue the Timaeus had the greatest influence on medieval philosophy. Even if you have studied Plato before, you are probably unfamiliar with the Timaeus, as the medieval philosophers were unfamiliar with the dialogues (like the Republic or the Symposium) that we tend to emphasize today. The Forms (Ideas) are mentioned briefly in the Timaeus, but they function as little other than ideas or models in the mind of the creator. We don’t find the kind of mystical eroticism of the Symposium or the Phaedrus – relatively little about the soul’s longing for God or the Good, much more about God’s providence in ordering the world and providing for our needs. Also, the Timaeus is the one dialogue in which Plato explicitly develops a doctrine of creation, a novel idea for Greek thought. The Timaeus contains an explicit design argument – an argument that the world we see could not be the product of chance or blind necessity, that it reflects the activity of intelligent purpose. Earlier Greek myths had used metaphors of growth and reproduction for the origin of the universe – Plato substitutes for this a theory of divine making. However, this is not a theory of creation ex nihilo (from nothingness). The creator faces a world divided into three realms: the world of Being, the world of Becoming, and the Receptacle of becoming (space). The world of Being consists of a system of Forms, eternal, which somehow constitute a living and intelligent being. (In later NeoPlatonic thought, this Being is identified with God or the One.) The creator-god uses the world of Being as his model. Before creation, the world of becoming consists of formless, indeterminate matter, filling a receptacle, space. Before creation, there was no time in the proper sense (since time corresponds to the movements of the heavens, which were not yet in existence). The creator first forms the four elements, by organizing matter into four regular three-dimensional solids: the pyramid, the cube, the octahedron, and the icosahedron. In addition, he forms the heavens from fifth element, consisting of dodecahedrons. Thus, physics and chemistry are grounded in a rational creation and are primed for study by means of geometry. At the same time, Plato recognizes two causal factors: the divine (God’s aiming at the best) and the “necessary” (the limitations imposed on God’s efforts by the prior, refractory features of matter). A large part of the book is devoted to physiology and psychology. The human soul consists of three parts: intellectual (head), spirited (chest), sensual (belly). Wrongdoing is not voluntary, but is always the result of flaws in one’s physical makeup or a failure of education, neither of which is liked or chosen by the wrongdoer. There is a mutual influence between the motions of matter within the body and the “motions” of the soul – Plato is very unclear about how this interaction is supposed to work. Although the soul is “immaterial”, it still has parts that take up particular spatial locations. The good soul is a beautiful soul, characterized by the right proportion. There is a kinship between the human being and the whole universe (the microcosm/macrocosm correspondence). The whole universe is a living, visible god. Comments on Timaeus Note the distinction between the realm of true Being (that which is "apprehended by intelligence and reason") and that of Becoming (that which is "conceived by opinion with the help of sensation and without reason"). "Opinion" is Plato's name for belief that lacks a sound basis in reason and knowledge. According to Plato, whatever is apprehended by intelligence is essentially unchanging. Only these unchanging things truly "are" -- the things apprehended by the senses and by common-sense opinion are constantly changing, shifting in and out of existence. This liability to change Plato takes as proof that they lack true "being": "always in a process of becoming and perishing and never really is". The realm of Becoming requires a cause. This is true not only of each part of that world, but of the whole as well. Thus, the whole realm must have had a beginning and must have been caused or created. Plato seems to rely here on a principle of composition: that the world, composed of things that lack true being, must also lack it. What lacks true being must derive what being it has from some cause. The whole realm of Becoming must depend on a cause that lies in the realm of Being, since being can be given only by something that has it in itself.

In his dialogue the Laws, Plato develops this argument as a proof of the existence of God, which proof he includes in the preamble to his ideal constitution (since Plato argues that every citizen should know that God exists and rewards righteousness). Note that Plato ends the first speech of Timaeus with an admission that his theological doctrines may not be "altogether and in every respect exact and consistent with one another," since in philosophical theology we merely "adduce probabilities as likely as any others". We ought to "accept the tale which is probable and enquire no further." Plato's God does not create ex nihilo: instead, "out of disorder he brought order." God fashions the world according to a pre-existing model, the world of "intelligible beings" which is the whole realm of true Being. Once the world has been created, the world itself "became a living creature endowed with soul and intelligence". Do we have then at least three divine beings: the realm of Being, God the Creator, and the World-Soul? Moreover, where should we locate God himself -- is he a part of the realm of Being? The whole realm? Somehow beyond the realm of Being? Plato derives the nature of the creation from the assumption that God created the most excellent possible creation. The unity and uniqueness of this world, its spherical shape, and the perfect circular motions of the heavenly bodies are all derived from this assumption. We also see Plato's principle of the triad, the necessity of an intermediary between any two related things, at work in the passage in which he introduces the four elements: "two things cannot be rightly put together without a third; there must be some bond of union between them." For some reason I don't comprehend, Plato insists that in the case of solid bodies, two intermediaries are required. So, the two basic elements of fire and earth must be joined by two intermediate elements, air and water. There is an important discussion of the nature of time. Plato argues that time and the heavens had to be created at the same instant. The sun, moon and planets were designed by God to "distinguish and preserve the numbers of time". The heavens are a "moving image of eternity." Before the heavens were created, there was no time. Although we say that God "was", "is" and "will be", in fact only the "is" is appropriately predicated of him, who lives in an "eternal present". Plato addresses the problem of the interaction of soul and body. He talks about the human soul as though it were a kind of subtle fluid or gas that "courses" through the body in a state of "perpetual influx and efflux". The soul is bound to the body by "little pegs too small to be visible". Sensations are movements in the body that violently shake the course of the soul. Similarly, the movements of the soul in its circular courses induces movement in the body, resulting in active behavior. Proper nurture and education is needed to shape the courses of the soul into their natural form, a form that constitutes mental health and that corresponds to true or accurate belief. Plato gives a positive role to the senses of sight and hearing, thanks to the edifying character of astronomy and music. "God invented and gave us sight to the end that we might behold the courses of intelligence in the heaven, and apply them to the courses of our own intelligence which are akin to them..and that we, learning them and partaking of the natural truth of reason, might imitate the absolutely unerring courses of God and regulate our own vagaries." Similarly, musical harmony has motions akin to the revolutions of our souls. Plato then presents the first mathematical theory of physics. Sometimes the ancient atomists, including Democritus, are credited with anticipating modern atomic physics. However, ancient, Democritean atomism was a scientific dead end, since Democritus thought that atoms came in an infinite variety of miscellaneous shapes and sizes. There could be nothing like a periodic table of elements in a Democritean universe. In contrast, Plato assumes that God would use regular, mathematical forms in shaping the fundamental particles. Ancient geometers had proved that there are exactly five regular polyhedra (solids whose surfaces are all exactly identical). Plato conjectured that these five shapes correspond to the five elements (earth, water, air, fire and aether). The smallest and sharpest shape, the tetrahedran, he identifies with the particles of fire. The cube was the fundamental particle of the one solid element, earth. Since the surfaces of three of the solids (the tetrahedron, icosahedron, and the octahedron) consist of equilateral triangles, Plato

conjectured that these elements can be converted into each other. Tetrahedrons (fire) have four sides, octahedrons (air) eight and icosahedrons (water) twenty, so two particles of fire can combine to form one particle of air, and two particles of air and one of fire combine to form a particle of water. (Note how this gives rise to something very like modern quantitative chemistry.) Plato's combination of mathematical form with physical models was remarkably prescient and formed the foundation for all future scientific progress. II. Aristotle (384-322 BC) Aristotle studied with Plato at the Academy for twenty years (from age 18 until 38), until Plato's death. He tutored Alexander the Great as a young man in Macedonia. After this, he returned to Athens to found his own school, the Lyceum. Followers of Aristotle are often call "Peripatetics", Greek for those who walk about. This probably reflected Aristotle's interest in empirical investigation, especially the observation of living things. The corpus of Aristotle's work was assembled by his students after his death, largely from lecture notes. The scope of his work is universal: formal logic and linguistics, physics, astronomy, meteorology, biology, politics, ethics and literary theory. One notable absence: mathematics, which seemed to interest Aristotle much less than it did Plato. Although we now think of Plato and Aristotle as representing two very different, even opposite, approaches to philosophy, many in late antiquity and in the middle ages thought of Aristotle as simply Plato's house logician. This impression has several sources: many influential philosophers of late antiquity (including Plotinus, Porphyry and Boethius) were eclectic, intent on fashioning a philosophy that synthesized the best of the Platonic and Aristotelian philosophies. Second, the only books available in Latin until the 13th century were Boethius's translation of Aristotle's logical works (Boethius's untimely death cut short his translation project). Third, medieval scholars (both in the Muslim and Christian worlds) misidentified a work as Aristotle's: the "Theology of Aristotle", which is in fact a collection of excerpts from the works of the NeoPlatonic philosophers Plotinus and Proclus. A case can be made that the common modern view exaggerates the difference between Plato and Aristotle. If we compare the later works of Plato (such as the Timaeus, the Laws, Parmenides, Theaetetus) to those of Aristotle, the difference in approach is not as great as it would be if we concentrated instead on Plato's early or middle-period works, such as the better-known Republic, Meno and Pheado. The mature Plato certainly does not neglect the importance of empirical observation or disparage the physical world as unworthy of the philosopher's attention. Plato subjected his own theory of the Forms to severe criticism in the Parmenides, and most of Aristotle's objections to that theory are based on Plato's own qualms. On Aristotle's side, Aristotle agrees with Plato that our knowledge of God is the highest form of wisdom, which in turn is the most important component of human happiness. Both believed that the study of the natural world must take into account the natural functions or purposes of things (teleology), and both used this scientific teleology as the foundation of their theories of ethics and politics. Aristotle's work on logic, the theory of the syllogism, seems to be based upon some earlier investigations of the form of valid or correct reasoning that was begun by the Sophists and continued by Plato. Boethius's translation of Aristotle's logical works helped to shape the intellectual life of the Middle Ages, putting an interest into logic and argumentation at the center. The disputation, a highly sophisticated and formalized mode of debate employing Aristotle's syllogism, became the most common exercise of the medieval university. Aristotle's theory of science, developed in the Posterior Analytic, had a profound effect on the development of science in the medieval and modern world. Although Aristotle clearly recognized that careful observation is an indispensable starting-point, the final form of science is that of a purely logical system, in which all of the general facts of nature are deducible from a set of "definitions". A definition for Aristotle is not a stipulation or description of the meaning of a word or phrase, but a correct formulation of the true nature of a certain kind of thing, a nature that explains why that kind of thing acts and reacts as it does. Aristotle posed a serious problem for Jewish, Islamic and Christian philosophers, since he believed that he could prove that the physical universe (the heavens and the earth) have existed for an infinite period of time and will continue to exist forever. Aristotle believed that we can see that the nature of time permits no first

or last moment, and if there is no first or last moment, then the processes of physical change must have no beginning or end (since time is simply the measure of such change). III. Plotinus (204-270 AD) Plotinus was the principal figure of a new school of thought, Neo-Platonism, one of enduring significance. Plotinus is a philosopher of the first rank, not, perhaps, at the same level as Plato and Aristotle, but certainly comparable to Epicurus, Aquinas, Descartes or Kant. Although obviously drawing on many ideas to be found in Plato, Plotinus was also an expert in Aristotle’s philosophy and makes use of many elements from it, especially Aristotle’s logic, his theory of causation, and his distinctions between form and matter and between actuality and potentiality. Plotinus’s system begins with three fundamental principles: The One/The Good, Intellect/Mind(Nous), and Soul. These correspond, roughly, to the world of Being, the Demiurge, and the living visible universe of Plato’s Timaeus. These are both paradigms (models, archetypes) and causes of the beings that make up our visible universe. The One causes Intellect, which in turn causes Soul, and the three together cause all finite things: the One causing things to exist, Intellect causing them to be what they are (to take on specific forms), and Soul causing things to move and change. Plotinus is not a monist or pantheist: he is not asserting that only one thing really exists, as did some of the ancient Greek philosophers (like Parmenides) and some varieties of Hindu theologians. He is a monotheist, a metaphysical monarchist. The One is the supreme cause of everything else, but the many finite things do really exist and are really distinct from the One. Plotinus’ monotheistic metaphysics helped to shape Aquinas’ thought, and, through him, all of scholastic philosophy. Plotinus influenced Pseudo-Dionysius, who influenced John Scotus Eriugena, and down to Aquinas. Plotinus developed a distinctive form of argument for God’s existence. Plotinus assumes that everything that is complex or composite must have a cause for its existence. This is true even if the composite thing has always existed, even if it couldn’t have failed to exist. Plotinus believed, unlike Philo and many other middle Platonists, and unlike most Christian thinkers (except, perhaps, Origen), that the visible universe has always existed, and couldn’t have failed to exist. Nonetheless, Plotinus insists that it must have a cause for its existence, including a cause for its present existence, something responsible for maintaining or preserving it in existence. Plotinus does not appeal to the fact that the visible world is changeable or contingent, but simply to the fact that it is made of composite things, that is, of things that have parts. Plotinus then argues that only an absolutely simple thing could provide an adequate causal explanation of the existence of composite things. He takes for granted that explaining the existence of composite things in terms of the existence of further composite things is no real explanation at all, given his assumption that the existence of a composite thing is never self-explanatory. Thus, Plotinus infers the existence of an absolutely simple One. The simplicity of the One is so absolute that can really say nothing about the One except: the One is the One. If we try to predicate some quality of the One, by saying, for example, that the One is beautiful, or even that the One exists, then what we say can be taken as true only by denying that there is any real distinction between what is signified by the subject and predicate. That is, if we say that the One is beautiful, we cannot mean that the One has beauty, because then it would no longer be absolutely simple. Instead, we would have the One and its beauty somehow combined into a complex fact. Rather, to say the One is beauty is to say that the One is Beauty itself, that there is, in reality, no distinction between the One and its Beauty. Similarly, to say the One exists is really to say that the One is existence. There is no distinction between what the One is and the fact that it is, or, as Aquinas will later put it, God’s essence is identical to his existence (and both are identical to God himself). It is instructive to contrast Plotinus’s view of God with those of Plato and Aristotle. Neither Plato’s Craftsman-God nor his domain of Being (the intellible living being) nor Aristotle’s God have anything like the absolute simplicity of Plotinus’s One. The Form of the Good in Plato’s Republic (and also the One of Plato’s Parmenides) give no indication of being personal or alive, as in some sense Plotinus’s God is, nor do they have any causal or active role in Plato’s system. Aristotle’s God is clearly alive and intelligent (i is a “self-thinking thought”), but its intelligent activity clearly implies some kind of complexity. We can

distinguish between Aristotle’s God’s existence and its activity. Similarly, Plato’s craftsman is just a very powerful and intelligent person, with all the complexity implied by that. Neither Plato’s nor Aristotle’s God is wholly other or infinite in the way Plotinus’s God is. This new kind of proof of God’s existence has several consequences: 1. Plotinus moves theistic arguments from the realm of physics or cosmology (that is, arguments for God as the First Cause of physical motion or as the Designer of cosmic order) to the realm of metaphysics (God as the absolutely simple cause of the existence of all composite things). 2. This greatly elevates our conception of the transcendence or otherness of God. An ultimate source of physical motion or a cosmic craftsman could be thought of as similar to things we are familiar with (celestial spheres or human craftsmen), only greater and larger. An absolutely simple cause of all existence is radically different from us and everything we find in the world. 3. This provides a basis for the so-called “negative” approach to theology as our primary mode of knowing God. We can more truly and straightfowardly say and know what God is not than what he is. We can say that he is not evil or imperfect in any way. We can even say that he does not think or know or even exist, if by these statements we mean that he does not have thought or knowledge or existence in the way that all finite thinkers, knowers and beings do. Plotinus characteristically says that God is “beyond” thought, knowledge, and even existence. 4. Plotinus’s proof gives us new grounds for believing in only one God. Plotinus argues that there could not possibly exist two absolutely simple beings, since for the two to be different, one would have to have something that the other does not, but any being that “has” some characteristic is not absolutely simple. Hence, whenever we have two distinct beings, at least one of them must be composite. The idea of divine simplicity that Plotinus introduced continues to be a subject of controversy in contemporary philosophy. Many contemporary philosophers have defended the Plotinian conception of simplicity, including Paul Helm, Brian Leftow, Norman Kretzmann and Eleonore Stump. However, the majority of Christian philosophers have in recent decades have attacked this conception of God as incoherent or even unintelligible. For example, in Does God have a Nature?, American philosopher Alvin Plantinga argued that Plotinus’s doctrine would make God into an “abstract” object, Being itself, Goodness itself, putting God into the same category of being as a number (like pi). Plantinga wrote that he could not even understand the claim that a person could be identical to its own essence or nature. Plotinus’s negative theology led to the further conclusion that philosophy alone cannot take us to a full knowledge or communion with the One, since the One lies beyond all thought. Instead, communion with the One is possible only through mystical, ineffable experiences. There are several respects in which Plotinus’s system is deeply at odds with Christianity. First, the One does not create the world – instead the world is said to “flow” from the One (often translated as “emanate”). This doesn’t imply that God’s causing of the world is unconscious, impersonal, or involuntary. There are, however, two or three differences between Christian creation and Plotinian emanation: (1) first, emanation does not entail that the universe had a beginning in time – Plotinus’s universe is eternally caused to be by God, (2) emanation is not a direct process – instead, God causes the world through a long series of intermediaries or instruments, starting with Intellect and Soul, and (3) the emanation of the world from God is necessary, rather than contingent. Christians emphasize that God might not have created at all – that creation was a free and even gratuitous choice of God’s. Even so, there are some similarities as well. In light of the Trinity, Christians did believe that God the Father created the world “through” in some sense the Son/Word, and even “through” the Spirit/Wisdom. And both Plotinus and Christians insist that God had no need to create, that creation was an act of the overflowing of divine love or benevolence. A second and more important difference between Plotinus and Christian thinkers concerns the nature of evil. According to Plotinus, ever step in the emanation of reality from God is a step away from Good and, therefore, a step toward evil. Each step in the causation of reality is a fall into deeper evil, culminating finally in the lowest form of reality, corporeal matter. This Plotinian account of evil conflicts with three themes in Christian theology: the goodness of the completed creation (according to Genesis 1), matter and

all; the Incarnation of God in the person of Jesus (body and soul); and the sacredness and spiritual power of the Sacraments (especially the waters of baptism and the bread and wine of the Eucharist). There is a third difference that will become clearer as we look at Thomas Aquinas’s theology. Plotinus describes the One as the Good, not as He who Is, or as Being itself. He places the Good beyond being or existence, but not beyond goodness. Hence, in Plotinus’s theory, there is a sense in which goodness is prior to existence. The existence of things is to be explained in terms of their goodness, not vice versa. The fundamental cause of the existence of things (God) does not itself exist. Aquinas, following what he took to be the upshot of the name God gives himself in Exodus 3 (I am that I am, or simply I am), took being or existence to be prior to goodness. Goodness is being-as-desired. Being itself, being-as-being, is always good, and God, as Being or Existence itself, does exist. Again, this controversy between the priority of goodness and being finds contemporary echoes. For example, Canadian philosopher John Leslie, in his book Universes, defends the Neo-Platonist theory that the fundamental cause of everything is an ethical principle (the principle that the best should exist), a principle that itself is prior to all existence. Contemporary Thomists would respond to Leslie by arguing that the idea of a non-existent cause is nonsensical. Thomists would argue that Leslie’s ethical principle has to be grounded in an actual being, namely, God, while Leslie argues that God’s existence is to be explained by reference to a prior ethical principle. Commentary on The First Ennead, Tractates Six through Eight Tractate Six: On Beauty Physical beauty pertains to both sight and hearing Plotinus seeks the essence (the true definition) of beauty: what exactly is beauty? He argues that it does not consist in symmetry alone, since some symmetrical things are not beautiful, and some beautiful things (like simple colors and tones, or beautiful ideas or souls) are not symmetrical. Why does the soul delight in beauty? Because it recognizes something akin to itself. The Soul exists at a higher plane of existence than matter, so physical beauty has to do, not with matter itself, but with matter that has been imbued with a beautiful form or pattern. This explains why we associate physical beauty with harmony and symmetry: a Form is always a unity, so when matter is organized by a Form, it takes on the Form's unity through mutual harmony and symmetry. In the case of the beauty of a physical simple, like a color, the beauty consists in the union of matter with light, which is in reality a Form. In fact, true light is immaterial and intellectual (recall a similar claim made by Philo). A greater form of beauty is that of the beautiful soul: one endowed with moral and spiritual virtues. The beautiful soul is concerned with true Being, while the ugly soul is occupied with matter and the body. The beautiful soul is purified from all physical preoccupations and consists entirely of Idea and Reason. Beauty is the real or authentic being, while ugliness is the principle of non-being. Beauty itself is identical to the Good, and is called the First (or the One). Here Plotinus sketches the neoPlatonic Trinity: the One, the Intellect (or "Intellectual-Principle" according to this translation) and the World Soul. How to obtain true Beauty: we must withdraw into ourselves, and turn away from material beauty (a mere shadow or copy of the true Beauty). If we purify ourselves morally and spiritually,we will fit our mind to "see" Beauty by an intellectual vision. The eye must become like what it sees -- so the mind must become like the One in order to see it.

Seventh Tractate: Primary and Secondary Goodness Everything that exists has some participation in the Good. To exist is to be unified and to exist, and these are in and of themselves good. Life is good -- does this mean that death is bad? No, since death means the liberation of the soul from the body, which is a transition to a better state. Life in the body is of itself evil but can be made (partially) good as the soul achieves virtue. Eighth Tractate: Origin of Evil No evil in the Good, the Intellectual-Principle or the Soul. Evil has no place either among the Beings (Intellect or Soul) or among that which is beyond being (the Good). So, evil is in the realm of non-being. Not in the sense of something that simply does not exist, but something of an utterly different order from Authentic Being. There must be such a thing as Absolute Evil -- absolute formlessness. That which is below all patterns, forms, shapes, measurements and limits. This is Matter, which is void of all good. All bodies, made of matter, partake of evil. The soul becomes evil when it turns from Being toward matter. We are not the source of evil. Evil holds and binds men against their will. The Cosmos is a blend of Intellect and Necessity. What is good comes from God, what is evil from the underlying matter (= necessity). So, once again, God does not create ex nihilo, and the ultimate cause of evil is beyond his control. Evil exists of necessity. It was impossible for the incoming Idea to conquer matter utterly: the sould cannot remain pure except by avoiding matter altogether.

III. Porphyry Porphyry was Plotinus’s student and editor. His works were widely read in the medieval period. His Isagoge was a commentary on Aristotle’s Categories, which is a work in which Aristotle describes the logical structure of the world, distinguishing between substantial things (“substances”), qualities, quantities, relations, places and so on (the ten fundamental “categories” into which all things can be placed). Historically, the most important part of the Isagoge is the introduction, in which Porphyry tells us what he is not going to discuss. The three questions or issues Porphyry laid out there summarized hundreds of years of inquiry and debate among the ancient schools of philosophy and they sparked intense discussion throughout the Middle Ages. These issues are often called “the problem of universals”, because they concern the reality and nature of universals, things that can be predicated of or exemplified by many things, like humanity, rationality, justice, triangularity or redness. Porphyry put the questions in terms of species and genera (general kinds of substantial things, like organisms or elements), but the same questions could be asked about qualities or relations. Here are the three issues: 1. Are universal real things, or are they found within thought alone? 2. If they are real, are they physical or non-physical? 3. If they are real, can they exist in and by themselves (as “separate” beings) or do they always exist and have their being “in” the things that exemplify them? Of these, the most important questions are 1 and 3 (relatively few have thought that universals were physical things). Question 1 divides so-called “realists” (who, like Plato and Aristotle, answer Yes) from socalled “nominalists”. Question 3 divides the extreme realists (like Plato) from the moderate realists (like Aristotle).

IV. Pseudo-Dionysius the Areopagite Dionysius serves primarily as a conduit between Plotinus and medieval philosophy. Dionysius’s philosophy is plainly drawn from Plotinus. Dionysius describes three ways we have of knowing God: negatively (by saying what God is not), virtually (by recognizing God as the first cause of everything else), and by way of super-eminence (by recognizing that every creaturely perfect pre-exists in a super-eminent form in God). Dionysius emphasizes that, although we can know that God exists, we can have no knowledge of his nature or essence (a distinction repeated by many later Christian thinkers). Dionysius uses NeoPlatonic names like the One or the Good to refer to God, and, like Plato and Plotinus, Dionysius asserts that God does not exist, that he lies “beyond existence”. Aquinas interprets (plausibly, I think) Dionysius not to mean that “God does not exist in any manner whatsoever, but that he transcends what exists in so far as he is his own being.” Dionysius makes some original contributions to our understanding of the nature of evil. Unlike Plato or Plotinus, Dionysius does not see matter as the ultimate source or the supreme paradigm of evil. Dionysius argues that nothing can be purely or wholly evil, since to exist at all is to participate to some degree in goodness. As he says, “all things, in whatever way they are, are and are good” (Aquinas will express this by saying that being qua being is good). If goodness were completely extinguished, there would be no life or being at all. Instead, evil can be defined as “incomplete good”. As later philosophers will put it, evil is the privation of good, something’s falling short of being as good as it could be. Dionysius rejects a dualism that sees good and evil as two equal and opposite forces (like yin and yang). He argues that no dyad can be the ultimate source of things, for every dyad has its source in some one thing. Thus, goodness is ontologically prior to evil. We can see here again the influence of Plotinus’s theory that all composite being must be caused by something simple.