The Central Role of Metaphysics in Duns Scotus’ Thought

When we ask what it means for something to exist – not what it is made of, not where it came from, but simply that it is – we are already doing metaphysics. Few thinkers in the history of Western philosophy pursued this question with more precision and daring than John Duns Scotus (c. 1265-1308), the Scottish Franciscan friar whose work earned him the title Doctor Subtilis – the Subtle Doctor. For Scotus, metaphysics was not an abstract luxury but the very foundation on which both philosophy and theology must stand. Without a rigorous science of being in its most general form, he believed, every other intellectual endeavor loses its footing.

Metaphysics as a “real theoretical science” 🔗

Scotus begins with a precise and somewhat technical claim: metaphysics is a “real theoretical science.” Each word carries weight. It is real in that it studies things as they exist in the world – not merely concepts or words about things, but actual beings. It is theoretical in that it is pursued purely for the sake of understanding, not for any practical outcome like building something or guiding action. And it is a science in the strict medieval sense: a body of knowledge that proceeds rigorously from self-evident principles to necessary conclusions through deductive reasoning.

This framing immediately distinguishes metaphysics from disciplines like logic, which deals with concepts and their relations, or ethics, which guides conduct. For Scotus, each genuine science must have a clearly defined subject matter that sets it apart from all others. Identifying the proper subject of metaphysics, therefore, becomes not a preliminary question but a central one. The entire character and scope of the discipline depends on how we answer it.

Being qua being: the subject matter of metaphysics 🔗

Scotus’s answer, drawn from and developed beyond Aristotle, is that metaphysics studies “being qua being” – ens inquantum ens in Latin. This means that the metaphysician does not study being under any particular description or restriction. A physicist studies material things as material. A biologist studies living things as living. But the metaphysician’s gaze falls on being as such – on whatever it means for anything at all to exist, regardless of its specific nature.

This is a demanding and genuinely puzzling project. What can be said about everything that exists, taken simply as existing? Scotus’s answer involves two interconnected domains: the study of transcendentals and the study of the Aristotelian categories. Both belong to metaphysics, and understanding each requires seeing how they relate to the fundamental concept of being.

Transcendentals: concepts that go beyond every category 🔗

Aristotle divided all finite beings into ten highest genera, called categories: substance, and nine types of accidents (quantity, quality, relation, action, passion, place, time, position, and state). This categorical framework was central to medieval philosophy. But Scotus recognized that some concepts apply to things across and beyond all these divisions – they are not confined within any category. He called these concepts transcendentals, because they transcend the division of being into finite and infinite, and the further division of finite being into the ten Aristotelian categories.

Being itself is the primary transcendental. But Scotus also identifies what he calls the proper attributes of being – one, true, and good – which apply to every being without exception. Something that exists is in some sense one (unified), true (knowable), and good (of some positive nature). These attributes are coextensive with being: wherever there is being, these attributes follow.

Beyond these, Scotus also identifies a set of disjunctive transcendentals – paired concepts such as infinite-or-finite and necessary-or-contingent. Every being must fall on one side or the other of each such pairing. While neither member of the pair applies to everything (not everything is infinite, and not everything is finite), the disjunction as a whole applies universally: every being is either one or the other.

Transcendentals and the knowledge of God 🔗

One reason the transcendentals matter so greatly for Scotus is their role in natural theology – the philosophical investigation of God without relying on revelation. Because being as such pertains to both God and creatures, Scotus thinks of metaphysics as a natural theology. If the concept of being applies only to creatures, then no philosophical argument could reach God at all. But if being applies, in however different a mode, to God and creatures alike, then from our knowledge of created reality we can reason upward toward the nature of the divine.

This is why the transcendentals carry such theological freight for Scotus. When we say that God is good, or that God is one, these terms are not just vague analogies borrowed from human experience. They point to genuine metaphysical properties that transcend every categorical boundary. The study of transcendentals is, at the same time, the study of what can be known about God through reason alone – making metaphysics indispensable for theology, not just for philosophy.

The Aristotelian categories and the structure of finite being 🔗

The second major domain of metaphysics, alongside transcendentals, is the analysis of the Aristotelian categories. Scotus is emphatic on a crucial point: the categories belong to metaphysics insofar as they are studied as beings; if they are studied as concepts, they belong to the logician. The same categories can be approached from two directions. The logician uses them as tools for organizing language and inference. The metaphysician asks what the things falling under them actually are, how they exist, and how they relate to being as such.

Among the categories, substance holds the primary place. Substances are beings in the most robust sense, since they have an independent existence: they do not exist in something else. By contrast, the other nine categories – the accidents – exist only in substances. Quantity, quality, relation, action, passion, place, time, position, and state (habitus) all depend on substances to exist at all. A color cannot exist floating freely; it exists in a colored thing. A size belongs to a sized substance. This dependency relation is not merely grammatical; it is, for Scotus, a genuine feature of how reality is structured.

Understanding this structure – how being is distributed across substance and accidents, and how each kind of being relates to being as such – is one of the central tasks of metaphysics. Scotus engages with these questions in his Quaestiones super libros Metaphysicorum Aristotelis, his extensive commentary on Aristotle’s Metaphysics, demonstrating both his deep engagement with the Aristotelian tradition and his willingness to develop and revise it.

The univocity of being: Scotus’s radical move 🔗

Perhaps the most controversial and consequential aspect of Scotus’s metaphysics is his doctrine of the univocity of being. Prior to Scotus, the dominant view – shared by Thomas Aquinas and rooted in Aristotle – was that the term “being” applies to God and creatures only analogically: in related but distinct senses. Scotus was the first scholastic to hold that the concepts of being and the other transcendentals were univocal – applying in the same sense to substance and accidents, and even to God and creatures.

Scotus’s argument for univocity is grounded in his view of what metaphysics, as a science, requires. If the concept of being applied only equivocally or analogically to the diverse objects metaphysics studies, the discipline could not be a unified science at all. A genuine science must have one coherent subject matter, not a loose collection of vaguely related topics. Univocity – the claim that there is one concept of being that applies, however differently instantiated, to God and to a stone – is the condition that makes metaphysics possible as a single, rigorous discipline.

This is not to say Scotus collapses the difference between God and creatures. He insists that while the concept of being is shared, God’s mode of being – infinite – is radically different from the finite mode of creatures. Finite and infinite are intrinsic modes of being, not differences dividing it into separate genera. The univocity thesis is, in Scotus’s own careful formulation, primarily a semantic and epistemological claim about how our concepts work – not a metaphysical claim that God and creatures share the same ontological nature.

Why metaphysics underpins everything else 🔗

It should now be clear why Scotus gives metaphysics such a central place in his overall philosophical and theological system. Without a sound account of being in its most abstract and generalized form, none of the other disciplines can stand on firm ground. Natural theology requires a concept of being that can reach God. Physics, biology, and the other special sciences require the categorical framework that metaphysics provides and validates. Even logic, which deals with concepts, presupposes that those concepts have their roots in real beings that metaphysics investigates.

In this sense, metaphysics for Scotus is not just one inquiry among others. It is the inquiry that makes the coherence of all the others possible. Scotus conceives of metaphysics as the universal science of the transcendentals – the concepts that apply to every possible being – and it is precisely this universality that gives metaphysics its foundational character. A philosophy or theology that bypasses metaphysics, in Scotus’s view, is building without a foundation.

Metaphysics, theology, and the limits of reason 🔗

There is a further dimension to Scotus’s view that deserves attention. He is a Franciscan theologian, not merely a secular philosopher, and he is keenly aware of what unaided human reason can and cannot accomplish. Metaphysics, for Scotus, is the highest achievement of natural reason. It can establish that God exists, that God is infinite, and that certain transcendental attributes apply to God. But it cannot, on its own, access the truths of Christian revelation – the Trinity, the Incarnation, the economy of salvation. Those truths belong to theology in a different sense, one that depends on faith and scripture.

Far from reducing theology to metaphysics, Scotus uses metaphysics to clarify precisely what theology, as a supernatural discipline, needs to go beyond. This is a delicate and sophisticated move: Scotus’s best ontology supports and is supported by his theological semantics, with each discipline reinforcing rather than undermining the other. Metaphysics defines the boundary of natural knowledge; theology begins where that boundary ends.

Scotus’s lasting significance 🔗

The influence of Scotus’s metaphysics extended well beyond his own lifetime. The doctrines for which he is best known – the univocity of being, the formal distinction, and haecceity (the “thisness” of individual things) – shaped scholastic philosophy into the seventeenth century and left traces in later thinkers from Descartes to modern debates in analytic metaphysics. His insistence that metaphysics must be a rigorous, unified science with a clearly defined subject matter anticipates later demands for philosophical precision that would define much of modern philosophy.

More broadly, Scotus’s project demonstrates that the question of what “being” means is not a trivial or merely verbal dispute. How we understand being shapes how we understand science, language, God, and the structure of reality itself. In placing metaphysics at the center of his thought, Scotus was not indulging in scholastic wordplay. He was insisting on something that remains true: that without a clear account of what it means to exist, everything we say about the world rests on unexamined ground.

What do you think? If metaphysics is the science of being in its most general form, does that make it the most fundamental of all disciplines – or does it risk becoming so abstract as to lose contact with concrete reality? And do you think Scotus was right that the same concept of “being” must apply, in some shared sense, to both God and creatures for natural theology to be possible?

References

1. https://plato.stanford.edu/entries/duns-scotus/
2. https://iep.utm.edu/john-duns-scotus/
3. https://iep.utm.edu/scotuskg/
4. https://www.rep.routledge.com/articles/biographical/duns-scotus-john-c-1266-1308/v-1
5. https://en.wikipedia.org/wiki/Duns_Scotus