Bl. John Duns Scotus — Photo taken from Fr. Anthony Casamento’s post, which can be found here, on

John Duns Scotus; The Trinity, Simplicity, Univocality, And Much More.

Sit down, grab a cup of tea, and relax, because this is a post I foresee being a bit long. Here, I attempt to break down the metaphysics of Bl. John Duns Scotus. The subtle doctor (as he is known) came after the time of Saint Thomas Aquinas. In this blog, I wish to take some time and explain his philosophy to those who want a simple understanding of the subtle doctor.

Act/Potency Distinction

The first place to begin is where John differs with Thomas on the question of Act and Potency. To quickly give a definition of the two, something is actual (or has Act) insofar as it is something at any particular time. Consider a red rubber ball. It is actual in that it has redness, is rubbery and is round. However, it has potency insofar as it has the potential to melt, become gooey, turn purple, etc. Potency becomes actualized when it is brought out by something else in act, thus becoming a cause.

So, how do Thomas and John differ on the distinction? For Thomas, the distinction is an actual distinction, whereas for John it is a formal distinction. [1]. There are three distinctions made in Scholastic thought, the rational distinction is a distinction made by the intellect, but doesn’t correspond in the thing in itself. On the opposite side is a real distinction, wherein the two things being distinguished exist and are separable. Formal distinctions occupy a middle ground where the two things are distinguishable, but are inseparable[2]. Michael Sullivan gives this helpful distinction regarding Socrates,

Socrates is one animal and is one rational thing, and both of those are one real thing, not two. You can’t separate the animal and the rational thing in Socrates the way you could separate his arms from his trunk or his substance from one of his accidents (say, his location) [3].

The second difference is how a thing’s principle of actuality is limited. To use an example, why isn’t a red rubber ball’s roundness perfectly round? Thomas would say it is because the matter of a ball is limiting the roundness, whereas John would attribute it to the insufficiency or limitedness of the causes[4].

Principle of Individuation

The question regarding “what is the principle of individuation” is one that arises from the problem of universals. In my kitchen there are 5 bananas, and yet they all share the property of being bananas (or banananess). Banananess is the universal which all 5 particular bananas have. When we ask what distinguishes those bananas from one another, Thomas would answer that it is the matter (or constituents) of the banana [5].

John’s answer differs. For John, universality and particularness can be approximated nicely as, “Horseness is nothing but horseness alone” — or in this case “banananess is nothing but banananess alone”. That is to say, for Scotus all individual things differ from one another due to some principle of “thisness” or “haecceity”[6]. Their individuality therefore exists prior in principle, and their banananess or horseness follows from that.

Both Thomas and John are indeed realists about universals. They believe banananess exists and is shared. However, John doesn’t believe that bananas needs to be distinguished by their matter, for their haecceity suffices (and is just as real a principle in its own right).

The Univocality of Being

Before we can begin this section, it would behoove us to get a few definitions out of the way. When we speak about word usage, there are three ways that we can approach it. The first sense is in a equivocal way, for those who remember the fallacy of equivocation, this is when we use the same word in two different ways. For example, the word “crane” can refer to either the bird or the construction machine.

When we use language in a sense of analogy, we are using a word in a way that has an underlying principle of commonality. When I say “I see” in an analogous sense, it could refer to understanding through one’s eyes, or understanding through demonstrating a geometrical equation (like the Pythagorean theorem). Both are different processes, yet involve some underlying commonality where we can apply the same word(s).

Lastly, there is using a term in an univocal sense, wherein the term is used in the same way. This way is most important for understanding John’s view of metaphysics -for those seeking to know more about Thomas’ view, I would suggest reading Edward Feser’s Scholastic Metaphysics, or search it up on his blog for a simpler summation.

In order to understand God and for John to construct his view of Metaphysics, he must build it on a univocal understanding of being. Metaphysics, for John, is the study of objects per se. As Peter King explains,

Scotus rejects the traditional claims about the subject of metaphysics. For the primary object must, by definition, be truly predicable of anything falling under it as a per se object. Thus if substance were its primary object, metaphysics would not deal with accidents at all, since accidents are not substances (even if existentially dependent upon them). But this is clearly false. Likewise, God cannot be the primary object of metaphysics, for not everything is God. However, there is a straightforward sense in which anything capable of real existence is a being. In Quod . 3.06 Scotus distinguishes several senses of ‘being’ or ‘thing’, the broadest of which is: whatever does not include a contradiction. He explicitly says that being thus broadly conceived is the proper subject of metaphysics ( Quod . 3.09). God, angels, and substances are all considered in metaphysics to the extent that they are beings, but they are no more the primary object of metaphysics than triangles are of geometry [7]

A substance is a particular or individual thing in question, whereas “being” is the principle by which something exists, or can exist. God is a being amongst others, but he differs in being the greatest or highest of them all. When we speak of God (saying God is good), we are using goodness as it commonly exists in all beings, except that God’s exists in the greatest intensity. Take the quality of being white, on the colour spectrum, we can have degrees in which something is more blindingly white than others. King calls this the modal distiction.[8]

Divine Simplicity

The doctrine of Divine Simplicity is the notion that God is, at least according to John, pure actuality. God isn’t capable of motion (or change) and hence has no composition of parts. What this means has variety, but as Lee Faber of the Smithy explains,

Divine simplicity is a negative doctrine, which holds that God has no parts or constituents. But it has been variously construed throughout the history of philosophy. Indeed, I would say that there is a continuum of views from strong to weak. A strong view, perhaps the strongest, is that of Plotinus, who denied that even the duality of thought and thought-about can be in God; consequently, he put the intellect outside God on a lower plane of being. Christianity in general has a very weak sense of divine simplicity, at least compared to the neo-Platonists (though beware! they live again in France). Christians have historically posited an infinity of objects for the divine mind and even place a Trinity of persons in God. The Church defined divine simplicity as a dogma at Lateran IV in 1215, though obviously this was no novelty. Defined is perhaps too strong a word; it was used in the creed of the council. All that we find is that God is said to be “omnino simplex” which is translated as “completely” or “entirely simple”. Subsequent councils have confirmed this, but as far as I know, have not specified what this means. The scholastics of the 13th and 14th centuries not surprisingly all defend divine simplicity. Yet they have somewhat different conceptions of it. For some, such as Bonaventure and Henry of Ghent, simplicity seems to indicate an activity of the divine essence (don’t tell David Bradshaw). Aquinas denies a series of possible compositions of God (quantitative parts, form and matter, nature and supposit, essence and existence, genus and difference, potency and act), as well as gives arguments: if God were composite he would be posterior to his parts, composites require an existrinsic cause, etc. This reveals, I think, that divine simplicity is a corollary of arguments for the existence of God. Certainly for Aquinas, and probably for all the scholastics, the proofs that establish the existence of God establish a being that is the explanation of all other beings, that than which explanation cannot go. To posit a complex being is only get part way to the end; for there still is a further cause, whether the parts themselves or some other extrinsic cause which joins the parts, which will terminate the explanation.
Scotus’ gives a series a proofs for divine simplicity based on particular and common middle terms. In the particular middle term he argues that God is not composed of essential parts, quantitative parts, or subject and accident [8].

So, for John, God is not a subject (or substance) containing accidents — that is to say, God as he exists does not have parts which are necessary for him to be what he is. Socrates is still Socrates with or without hair. He does not contain anything that is quantifiable (like 4 limbs, or being 6'5").

Lastly, God doesn't have any essential parts. An essential part is a part of a things real (or essential definition). The essential definition of man is “rational animal”, on the material side are things are our bodily parts essential for survival, and on the spiritual side is our rational soul [9].

But, what does this mean of the things that we can predicate of God, like omnipotence, omniscience, omnipresence, and omnibenevolence? As stated earlier, John considers those as modal distinctions. Why aren’t these considered parts? Well, they don’t allow for potencies (which are only present for finite substances).

If one looks to a chart of Aristotle categories of existence, substance can be subdivided into finite and infinite being. A thing is rendered as a finite being or substance when he is qualified with any particular quality. If I am a man with the qualities of “animality”, then my potency (or power) is both enabled and limited by it. God needs to be infinite by nature, so his infinite being isn’t limited by any quality really distinct from him. Rather, he is by the nature of his being the highest of all beings, and his qualities are only a reflection of his modal status.

Aristotle’s ten categories

Or, that is to say God is not predicated in a way which is In quid (a predication in response to “what is it”; what is a man? a rational animal). Rather, he is predicated in In quale (a predication regarding “how something is”; how hot is it? hot enough to cook a steak on the pavement) [10]. God is co-extensive with all that he is In quale, as he is the highest of all being he is never really distinct or separable from what he is. But we can still meaningfully differentiate those qualities.

Now, at this point we might want to get into what they are. For John, like Anselm, he builds a hierarchy of qualities wherein it can be attributed to God if it is better to have (rather to not have). They all have their character in their way with God insofar, as stated, they have the highest intensity. To speak of infinite being isn’t to speak of a genera and difference (that is, species and genus) — for example a man is an animal (his genus) but he differs from others in that he is a rational one (his species)- hence even if the term ‘finite’ is univocal to both finite and infinite [11]. God is not one being among many, but the purest instance of being.

The Trinity

Now that we know God can have some distinction under John, while remaining pure being, how can he explain the Trinity? Certainly the trinity constitutes a real distinction, since the Son isn't an intensity resulting in coextensivity in being. The first thing to note is that modal distinctions are just one kind of formal distinction. Michael Sullivan explains it at large,

I think that this way is through Bl. John Duns Scotus’s formal distinction, the distinctio formalis a parte rei, formal distinction on the part of the thing. This kind of distinction finds the middle ground between fully real and merely notional distinctions, but it is subtle and more difficult to grasp than the other two. Let’s try to get a sense of it through a few examples.
Perhaps most people have seen those visual puzzles that seem to produce an optical illusion. On a piece of paper there is a single figure in black ink. What is it? Viewed in one way it is clearly a picture of two black faces turned towards each other with white space in the middle; viewed from another way it looks like a white cup with an incomplete black outline. Which is the true picture? Clearly both are “there.” When asked how many images there are we have to say that there is one figure or shape but two pictures or two images. They are not merely notionally distinct: a face is not a cup and a picture of one is not a picture of the other. And yet they are not really distinct: one cannot be removed or changed without destroying the other. The puzzle has been constructed such that here really is one shape or figure and two pictures or images, and these images are formally distinct [12].

The distinction between the Father, Son and Holy Spirit are relational in the divine substance. Much like the analogy that Sullivan gives, the Persons of the Trinity cannot be separated from one another, introducing no potency, or possible difference. This answers how they can be distinct (hence three), but how could they be one?

A good way of explaining this is analogizing the divine essence, as a universal to the particular members that are identical to it in the sense they all participate in it. All particular humans share a common humanity (that is we have a universal). However, no two humans are formally identical and are distinct and separate. God however has no parts due to his infinitude. The divine substance is one and exists in all members, thus they share the same oneness, but they differ in their relation to it, and hence they are three.

To close with Sullivan,

The key is to properly define the terms and distinguish the kinds of identity involved. But once this is done there is no logical problem at all, because the doctrine does not affirm and deny the same thing and in the same respect:
2. Divinity of Persons: The Father is God; the Son is God; the Holy Ghost is God.
It is orthodox to reformulate this as:
2a. Divinity of Persons: The Father, Son, and Holy Ghost are identical with respect to the divine essence.
And now:
3. Distinctness of Persons: The Father is not the Son; and the Holy Ghost is not the Father or the Son.
It is orthodox to reformulate this as:
3a. The Father, Son, and Holy Ghost are distinct with respect to their personally constitutive relations of origin.
So: The divine persons are identical in one respect and distinct in another respect. This is very different from saying “3=1” or “~(things which are equal to the same thing are also equal to each other)”.
As far as I’m concerned this dispenses with, at least, any obvious contradiction [13].

End notes

[1] — Edward Feser, Scholastic Metaphysics, 36

[2] — Michael Sullivan, Feser’s Scholastic Metaphysics: A Book Review, Part II,

[3] — Ibid

[4]- Edward Feser, Scholastic Metaphysics, 37

[5]- Ibid, 198–199

[6]- Stephen D. Dumont, A Companion To Philosophy In The Middle Ages, 360–361

[7]- Peter King, The Cambridge Companion to Duns Scotus, 17–18

[8]Lee Faber, Divine Simplicity I,

[9] Thomas M. Ward, John Duns Scotus on Parts, Wholes, and Hylomorphism, 47–48

[10] Peter King, The Cambridge Companion to Duns Scotus, 20

[11]Jan A. Aertsen, Medieval Philosophy as Transcendental Thought, 427–428

[12]Michael Sullivan, Divine Simplicity and the Formal Distinction, Part 2,

[13] Michael Sullivan, Contradiction in the Trinity?,

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