Fr. Seamus Mulholland
The Metaphysics of John Duns Scotus
The ecclesiastical condemnation of Aristoteleanism and Arabian philosophy in 1277, which included some of the theses of Thomas Aquinas, had a profound influence on the subsequent development of medieval philosophy. Of course, opposition to Greco-Arabian philosophy was nothing new in the 13th century. Its opening decades had seen the newly translated work of Aristotle and Averroes forbidden; yet their vogue spread, and in the years that followed a reconciliation was attempted, with varied success, between Christian dogma and the 'new learning'. The 'heresy' of Latin Averroism as the end of the century only confirmed the suspicion of the traditionalist theologians that any Christian who accepted the credentials of Aristoteleanism must arrive at conclusions contrary to faith. The great condemnation of 1277 expressed their renewed reaction to Aristotle and left an even deeper impression on subsequent scholars of the inadequacy of philosophy and pure human reason, in the name of theology. If, as had been claimed, the 14th century is a period of criticism, it is above all, a period of criticism, in the name of theology, of philosophy and the pretensions of pure reason.
The attitude of Duns Scotus (1266-1308) of the Franciscan Order, towards Aristotle and philosophy in general is seen in his Object of Human Knowledge. According to Aristotle, the human intellect is naturally turned towards sensible things from the way is must draw all its knowledge by way of sensation and abstraction. As a consequence, the proper object of knowledge is the essence of a material thing. Now, Duns Scotus was willing to agree that Aristotle correctly described our present way of knowing, but he did contest that he had said the last word on the subject and that he had sufficiently explained what is in full right the object of our knowledge. Ignorant of Revelation, Aristotle did not realise that Man is now in a fallen state and that he was describing the knowledge, not of an integral Man, but one whose mode of knowing was radically altered by original sin.
Ignorance of this fact is understandable in Aristotle, but it must have seemed inexcusable in a Christian theologian like Thomas Aquinas. The Christian, Scotus argues, cannot take Man's state as his natural one, nor, as a consequence, the present servitude of his intellect to the senses and sensible things as natural to him. We know from Revelation that Man is destined to see God face-to-face. This would be impossible to achieve is the material object of Man's knowledge was restricted to the essences of material things, for God is not contained within their scope. To be open to the vision of God, the intellect must have an object broad enough to include Him, and the only one that satisfies this condition is Being (ousias). Being, therefore, in its full indetermination to material and immaterial things is the first and adequate object of the intellect.
When as a theologian Duns Scotus made this decision, he was not only assuring the human intellect's capacity for the beatific vision; he was also making metaphysics as a science possible by marking out its proper object. Natural philosophy moves in the realm of finite mobile being and theology in that of infinite being. Metaphysics, on the other hand, has for its object being as being, or the pure undetermined nature of being. For Scotus this is not a logical universe. It is a reality, and the most common of all. Taken simply in itself, the notion of being abstracts from all the differences of beings. That is why it is, for the metaphysician, univocal, having one and the same meaning when applied to all things. Only in its finite and infinite modes is being analogical.
Being has, consequently, a univocity in Duns Scotus which is not found in Thomas Aquinas. For Thomas did not treat of being as if it were a nature or essence; rather it was for him that which is, at whose centre is an act of existing. And since every act of existing is irreducible to every other, there is a radical otherness in every being which the work of abstraction can never erase. That is why in the philosophy of Thomas Aquinas being is, for the metaphysician, not a univocal, but an analogical, concept.
It was the Arabian philosopher, Avicenna, who taught Scotus to conceive of every essence in an absolute state, natura tantum, and at the same time suggested to him his solution of the classic problem of universals. The Scotist nature, like the Avicennian, is simply what the definition of it signifies. Now, neither individuality nor universality is included within thje definition of any nature. When, for example, I define 'humanity' I mention its essential parts, 'animality' and 'rationality', but I do not see whether it is individual or universal. Indeed, in itself, it is entirely indifferent to being one or the other or both at the same time. It can be individual in real existence and universal in mind and still remain basically the same nature, for these modalities are entirely accidental to it. Suppose that the nature were of itself universal. Then it could never be individual; but as a matter of fact it is individual in the world of existing things. On the other hand, if it were by its very nature individual, it could never be universal, but it is universal in the mind. Consequently, the nature in itself must be absolute, abstracting from both individuality and universality.
In the metaphysical architecture of Duns Scotus absolute nature does not exist as such. Humanity, for instance, does not exist except in individual men and women and in the concept which we form of it. But it is not on that account simply a conceptual entity. Socuts says that it is a real being. This real being is contracted or limited by an 'individual difference' or 'haecceity', commonly known in Scotists studies as 'thisness' which renders the nature individual. Following upon this contraction of the essence or the nature, the individual is actualised by existence, which, at least in creatures, is the ultimate act of a thing, related to it simply as a mode of being.
If this is true, it is then evident that essence plays the central and primary role in the metaphysics of Duns Scotus. The metaphysical nucleus, so to speak, of an individual thing is an essence which is limited by different modalities which are purely accidental to it. That is why the metaphysical universe of Duns Scotus has been called 'essentialist,' in distinction to the 'existentialist' metaphysics of Thomas Aquinas (in calling the metaphysics of Thomas Aquinas 'existentialist' there is no intention of using the word as it is applied to the thought of such moderns as Satre or Marcel. It is used simply to express the primordial importance of the act of existing in that metaphysics), in which the metaphysical centre of an individual thins is an act of existing and its essence is but a limitation of that act. Because they do not agree in their notions of being, the metaphysics of Duns Scotus and Thomas Aquinas are fundamentally different. To confuse them and to equate Scotism with Thomism is simply to invite a gross misunderstanding of both doctrines.
On the other hand, seen in its own light, the architecture of the metaphysical universe of Duns Scotus is entirely intelligible. He carefully distinguishes between two orders of real beings: the order of beings (res) and the order of formalities or realities (realitates, formalitates) which are in things. Things are such that one can exist in separation from the other, if not naturally (like Peter and Paul), at least by the omnipotence of God (as matter can exist apart from form). Realities or formalities, however, cannot possibly exist separately. They are only formally non-identical, in the sense that one is not contained within the formal definition of the other. In Peter, for example, rationality is not contained within the definition of animality and his individuality as Peter is not contained within the definition of his humanity; otherwise there could be no animality which is not rational and no humanity other than Peter's.
What is markedly characteristic of the metaphysics of Duns Scotus is that he attributed reality even to these formalities. They are not simply abstractions of the mind (Aquinas); they abstract from each other even before the mind considers them. Each has a real being of its own and a real unity distinct from that of individual things. Peter and Paul, for instance, are each numerically one. But in them there is present humanity, animality, substance etc., each of which is formally non-identical with the others and constitutes a real being with its own specific or generic unity. True, Duns Scotus always maintained that individual things are most worthy of being called 'real', and that their numerical unity is a 'major unity'. Still, formalities are also real, and their generic or specific unity is for a him a real 'minor unity', and not simply a unity in the conceptual order.
Scotus conceived of an individual thing, then, as a coming together of of many formalities or natures of this sort. All of which are made individual or concretised by an 'individual difference' or 'haecceity'. But even though these formalities are individualised in things, in their own order they remain common of universal. That is why Scotus can say, paradoxically, that only individual things exist, but that there is something common in reality which is not of itself individual. This means simply that in the order of existing things there are only individuals: there are no existing universal things. But in the order of formalities or essences there are common natures which guard their commonness within their own order even when they are individual in the order of things.
The reason why Scotus says that there are common natures in reality is to assure a suitable object for knowledge. The primary object of knowledge and science is not individual things but universals. Now, there are two kinds of science: one which concerns conceptual entities, namely, Logic, and another, such as physics and metaphysics, which concerns real Being. Since the object of both kinds of science is universal, there must, then, be two kinds of universals: the complete universal, which is the product of the intellect and the object of logic, and the incomplete universal or common nature which is the object of the science of real being -metaphysics.
The metaphysical universe of Duns Scotus, therefore, is people not only with individual things but also with real common natures which the intellect has merely to eek out to read their intelligible messages. In such a world even the sense perceive a reality which is in a way universal. According to Duns Scotus, the object of sensation is not properly an individual thing as individual, but a reality common to all sensible objects of one genus, the greenness, for example, of all green things. Under these circumstances there is no need of an abstractive process of the intellect, in the way which Thomas Aquinas proposes, by which the intelligible object, bearing the stamp of singularity in a sensible image, must be rendered universal and actually intelligible in order to be known. For the object present to our cognitive faculties is a common nature in which, the Agent Intellect can read, as an open book, the intelligible object from which the concept will be born.
By his insistent realism of common natures, Duns Scotus placed himself in the long line of medieval Christian Platonists, all of whom agree in some way that there is a universality or community outside the mind corresponding to our universal concepts. But, of course, historical Platonism is realised in very different forms. The rather crude realist philosophies of Boethius and John Scotus Eriugena (often confused with Duns Scotus) and William of Champeaux are a far cry from the refined realism of Duns Scotus; but the same Platonic inspiration between them can be seen behind them all. And just as medieval Platonism aroused the unrelenting criticism of Peter Abelard, so the Platonism of the 14th century found an even more formidable opponent in William of Ockham.