216. One of a Kind: Gilbert of Poitiers on Individuation

Posted on

Gilbert of Poitiers proposes a unique way to explain how each individual is the individual it is.



Further Reading

• L.M. de Rijk, “Semantics and Metaphysics in Gilbert of Poitiers: a Chapter of Twelfth-Century Platonism,” Vivarium 26 (1988), 73-122 and 27 (1989), 1-35.

• C. Erismann, “Explaining Exact Resemblance: Gilbert of Poitiers’s Conformitas Theory Reconsidered,” Oxford Studies in Medieval Philosophy 2 (2014), 1-24.

• J.J.E. Garcia, Introduction to the Problem of Individuation in the Early Middle Ages (Munich: 1988).

• J. Marenbon, “Gilbert of Poitiers,” in P. Dronke (ed.) A History of Twelfth-Century Western Philosophy (Cambridge: 1988), 328-52.

• L.O. Nielsen, Theology and Philosophy in the Twelfth Century (Leiden: 1982).

• H.C. Van Elswijk, Gilbert Porreta: sa vie, son oeuvre, sa pensée (Leuven: 1966).


Otter Bob on 30 March 2015

Hello Peter,

Hello Peter,

[sorry, this was suppose to come in last week but had trouble posting]

I'm intrigued but perplexed by issues in this podcast and I have questions. I hope I'm not making this too complicated by going into such details. That's why I am submitting separate posts. In a way, I hold you responsible for my lengthy remarks. Since the beginning of these podcasts, you have forced or, at least, goaded and stung me into a closer study of what primary texts I have. And that has led to pondering over some of the secondary materials. I hope I have come to a more nuanced and careful mode of study for it has produced a more extensive type of thinking and writing. What can I say but Thank You.

So first, why do you say (circa 11:37) “For Aristotle and his followers, some thing's place is, strictly speaking, the boundary of whatever is containing it, for instance, the inner boundary of the air in contact with me right now. If place is determined by the thing placed inside it, how can place do the job of individuating that thing? The problem here is that Groucho's place is defined, indeed, individuated with reference to Groucho, not the other way around.”

I understand that you are trying to show that, given the distinction between a substance and its accidents, the accidents, such as place, cannot individuate the substance because of their posterior and dependent position. But isn't it true that Groucho's place, as opposed to the substance Groucho, is what it is (is defined) by reference not to Groucho or his outer skin? Rather, is not his place determined by the limits of the containing body immediately in contact, for instance, all the containing limits of that thick surrounding cigar smoke? And if that is true, it seems that neither Groucho nor his place are defined or even individuated by Groucho as a whole organism or by his outer skin. Rather, isn't it that Groucho, as a whole, is delimited (not defined in an Aristotelian sense) by the smoke, but his place just is (by its very nature and thus defined by) the limits of the containing smoke? How can the reverse be true—that Groucho defines and individuates his place—when what seems to be prior and causes his place to be so is the contacting limits of the surrounding body?

Otter Bob on 30 March 2015

More Questions on Place

Do I have this right? While trying to make clear Boethius' own explanation of why the accidentalist's position is circular, you bring forward the example of the humor of the Marx brothers' films and apply a dialectical principle of Socrates, to which I was first introduced in the study of Plato's Euthyphro. (To be fair and because you consider this a fundamental confusion, I want to quote at length. The remarks in brackets[...] are my glosses and this citation begins circa 12:44.)

“At the root of all these difficulties is a fundamental confusion. The accidentalist account is plausible because we do use accidents to tell things apart [that it is so that they are different]. We really do tell Groucho from Harpo by noticing that he is, for example, the one with the cigar and not the one with the blond wig. But that doesn't mean that accidents really account for the distinctness between things [why it is so that they are different]. How could they, if accidents depend upon those very things? This would be like saying the Marx brothers' movies are funny because people laugh at them. It's true that these two things do go together. Funny movies do provoke laughter, and we tell a movie is funny by the fact that people laugh at them [that it is so]. But it's because the movies are funny [why it is so] that people laugh, not the other way around.”

Applying this to body and place, I ask:

1) Is this body limited by (the limits of) the surrounding container because that is the body's place?

Or  2) Is that the body's place because (the limits of) the surrounding container limit it?

Surely, it is not the second? The surrounding container not only determines that the body is in a place but also it gives the cause of why it is in that place. The surrounding container is what makes the body be in a place.

Let me turn this into two corresponding statements and then I can pose my conundrum:

1) The place of a body is determined and individuated from other places by the body's own outermost boundary.

2) The place of a thing is determined and individuated from other places by the contacting boundary of the container that surrounds it.

But if 1) is true, then the only way a thing can change place is by changing its outermost boundary. Isn't it absurd that in order for a thing to move it must exchange a part of itself?

But if 2) is true, then the place of a thing can change, without the thing itself moving, simply by its container moving away and another container with its own limits coming into complete contact with the thing. Isn't it absurd that a thing can change places without moving? (or maybe it isn't)

[Do I hear Aristotle saying, “In a way, 'Yes'. But in a different way, 'No' “?]

I wonder if I must conclude that there is no such thing as a body's place or that place is something very different from these (?).

In reply to by Otter Bob

Peter Adamson on 30 March 2015


Wow, thanks for these detailed posts! I'll take the place issue first. I have actually thought about the issue you're raising. I think there is a simple and good-enough-for-these-purposes answer: even if the inner boundary of the smoke is not an accident of Groucho, it is an accident of some body (the smoke), so it is still posterior to something that had already to be individuated. I think there is however a sense in which that inner boundary also depends on Groucho, since it wouldn't be there if Groucho weren't present. In any case everyone working in this system should agree it is accidental and therefore posterior to substance which was my main point. Not sure if that makes you happy?

In reply to by Peter Adamson

Otter Bob on 31 March 2015

Too Nit-Picky?

I agree. If the smoke wasn't yet a particular thing (had not yet been individuated), then the place of Groucho (the contacting boundaries of the smoke) would not exist.  I'm quite willing, for these purposes, to accept the substance/accident distinction, and I agree that accidents, as such, are posterior. But that wasn't my issue. I was concerned with “Groucho's place is defined, indeed, individuated with reference to Groucho, not the other way around.”

I don't want to be nit-picky here (certainly not in a, soon to be, Scholastic setting), but you still say, “there is a simple and good-enough-for-these-purposes answer: even if the inner boundary of the smoke is not an accident of Groucho, it is an accident of some body (the smoke), so it is still posterior to something that had already to be individuated. I think there is however a sense in which that inner boundary also depends on Groucho, since it wouldn't be there if Groucho weren't present.” In what precise sense? Is it that if cigar-smoking Groucho wasn't present , then his smoke wouldn't be there? Or what? I suppose I would go along with an understanding “that is a simple and good-enough-for-these-purposes.” But not one that, in the end, misleads us.

I am more interested in anything you have to say about the conundrum formed by those two statements at the end. I think I have worked out an Aristotelian answer but for brevity's sake....  And I just thought it odd that some thing that is said of (is predicated of a substance (as a place is ascribed to or predicated of Groucho) could inhere alone in another substance (that the boundaries of the smoke surrounding Groucho are in just the smoke). But we're getting rather deep into this issue—perhaps too deep for this podcast format. So, we can move on, if you wish. You have more places to go than I.

In reply to by Otter Bob

Peter Adamson on 31 March 2015

Smoke and mirrors

No, you're right: the smoke would still be there (well maybe smoke is a misleading example because Groucho is the one smoking, but if we go with a standard example like the surrounding air, the air would still exist without Groucho). My point is that the _boundary_ would not be there, since it is because Groucho is displacing the smoke or air and creating the boundary. This would not be true with all examples, admittedly: e.g. the inside boundary of a containing jug in no sense depends on the fluid in the jug, in that you could empty the jog and the boundary would stay as it is.

Otter Bob on 30 March 2015

One Last Problem

I don't understand how Gilbert's two following positions can support the claim that there are no universal things. To paraphrase:

1) Only a substance and not it's characterizing features can be an individual. The features are instead called 'dividuals'. (circa 14:38)

2) At least for individuation, essential and accidental features of a thing are on a par. (circa 16:25)

I do understand that it is the “total form” that individuates substances. It is “...the totality of singular characteristics which collectively guarantee the thing's individuality.” (circa 17:50)

So we fine that only substances can be individuals. The features of substances, called 'dividuals' (recognizing no distinction between essential and accidental) are singulars. And to quote (circa 19:00), “We wanted to explain in the first place how it came to be that there are single things in the world and not just universal things. Nothing can exist without being singular.”

Well, substances exist, so they are singulars also. So both substances and their features are singulars, but only substances are individuals. And the “total form” of a substance is also a singular. Each human possesses its own singular humanity.

But –and here is the problem--”We arrive at a universal by noticing the similarity between singular characteristics....But, Gilbert insists, everything that really exists is singular. Universal humanity, freed from connection to any individual human, is only a conceptual construct.” (circa 18:12) But the similarity between singular characteristics, e.g., Groucho's humanity and Harpo's humanity, is, I assume, a similarity that really exists in the world also, along with Groucho, his singular humanity and singular choking cigar-smoking ad nauseam.

Let's turn to a real example: Glenn and Peter Adamson, being identical twins, are very, very similar in their features. One might even say “substantially so.” But surely there are some differences, however slight or minute. Not to split hairs, but surely one has just a few more hairs left on his head than the other. But they both can truthfully be called “bald” because of the similarity of having most of the scalp barren and exposed. But here is what makes me rub my head in wonderment. Any similarity involves an identity. And any identity produces a universal. How so? Well, they both are bald. True, one might have a few more hairs hanging on (I shan't say “by a hair”), but, nevertheless, they are both bald. We could say, perhaps without cutting it too fine, that one is less bald than the other. But “more” and “less” are quantifiers and they pertain in relation to the same one thing, unless we are equivocating. And I don't think Gilbert wants to do that.

Having combed that example for all its worth, I will cut away from Glenn and Peter and turn to another example to add evidence for what I take to be a bald fact. Your collie and my retriever are both dogs—not the same kind of dog or even the same dog—but both are dogs, and not in an equivocal sense. They are identical in being dogs. If they are not identical in some respect they could not be similar in any way. “But,” Gilbert might say, “each of their doggedness is not the same as the other. They are only similar or conforming to each other.” “And how is it, “ I might ask, “that each of their doggedness conforms to the other?” What else can be said except there is some one thing they have in common. Either that or we must find another similarity between their doggednesses. But that goes on ad infinitum, and Gilbert and other nominalists lose their claim that nothing can exist without being a singularity. Somewhere the real similarity of singulars must end in an identity—a one over a many. And that is a real universal. Can we anticipate that the next episode on mereology will clarify this?


In reply to by Otter Bob

Peter Adamson on 30 March 2015

Hair-raising issues

I'm totally going to steal some of your hair-related puns in a future episode.

But to the matter at hand. Firstly I'm glad to see from your summary of how you understand Gilbert's position that you get it perfectly, which makes me feel like I explained it successfully (I was worried). Really your objection has to do with the more general issue of accounting for similarity on a nominalist theory - hence it is one that can be raised against Abelard also. This won't be addressed in the Arlig interview exactly, though we do talk about universals as parts and wholes; but we have more to come on nominalism especially when we get to Ockham. So we're not done with this yet. To give a preliminary answer though, I think the nominalist would say that you can't assume that some third thing is needed to explain the similarity (or difference) between two similar (or different) things. That is just to decide the issue in advance, in favor of realism. What they are going to say is that the two cases of doggedness are similar in being dogged, but comparing them and generalizing is something only we do -- because everything real is singular. The realist though is going to feel that if the similarity is something real in the world, then there should be some real thing out there that explains it. (I tend to have sympathy for this actually.)

In reply to by Peter Adamson

Otter Bob on 31 March 2015

But Seriously (?)

Yes, I'm seeing this as a problem for any nominalist. But I certainly don't want to beg the question and “assume that some third thing is needed to explain the similarity (or difference) between two similar (or different) things.” So also, the nominalist should not be allowed to argue that “because everything real is singular,” [then] “comparing them and generalizing is something only we do.” I do not accept yet his reason why there are similarities (or differences), nor do I expect him to grant, as an assumption, that there is some one identical thing involved. But I am looking for a cause of the similarity and he cannot, without similarly begging the question, claim that two similar things are so because we compare and generalize from them. The question for him is then: how do we do that? On the basis of what in the things or in us do we do that?

Let's try it once more, going more slowly.  We have two individual dogs. They are similar, not identical. How are they similar? They both have the property of being a dog (call it, doggedness).  “They each have their own doggedness,” says the nominalist. “Are, “ I ask, “these two properties, one for each dog, the same or different?” The nominalist will say, “Not one and the same property. They are only similar properties.” But how they similar? You suggest, Peter, that “what they are going to say is that the two cases of doggedness [being a dog] are similar in being dogged [the cause]....” What?!   Each case of doggedness is dogged? The property of being a dog is itself dogged? The nature of a dog is itself a dog? Doggone it! I don't think I'm alone in being confused. (I'll confess to probably making the worst case out of what you said.)

We can halt here until Ockham. But I and my dog are going to be wary of getting a shave. We, at least, need all the fur we have.

Playfully, Otter

In reply to by Otter Bob

Peter Adamson on 31 March 2015


Yes, that's definitely the problem. Abelard's solution (or if you're being unsympathetic, his dodge) is to invoke the "status" of being-a-dog, and he explicitly argues that this is NOT a thing. So he would I think just resist your attempt to reify the dogginess as a "property": rather, what there is, is a dog, which is similar to other dogs in that they are also dogs. He's a realist in that he thinks that things do come divided into natural kinds; it isn't just a matter of custom or whatever that we distinguish dogs from non-dogs. But the dogginess itself is not something real, all you have out there in the world is dogs. (He can apply the same analysis to accidents, like two instances of a color.) Not sure if that helps?

In reply to by Peter Adamson

Otter Bob on 1 April 2015

Thanks, Peter, for a good

Thanks, Peter, for a good discussion.  On I go, but I'll still be working on these problems.

Michael Gebauer on 30 April 2015


Is the notorious idea of a ‘haecceitas’ already in the game here, or does that come later?

In reply to by Michael Gebauer

Peter Adamson on 30 April 2015


Good question; I think only later, unless you count "Platonity" already found in Boethius which I think I mention in this episode. But for the full blown theory I guess we have to wait until Scotus?

Jordan on 25 July 2022

This question that Gilbert…

This question that Gilbert is trying to answer is some pretty interesting food for thought. I feel like the first thing I need to defend is why I never saw this as a problem before. And maybe it's best to chalk this up as being over-invested in categorization - which I know was a focus of philosophy since its roots, but is now seen as less hard-and-fast. Eg fish may be categorized as such in every day life, but that doesn't mean they have any actual relation to each other. 

Anyway, the thing I'm inclined to immediately say is the determining factor is consciousness. But that puts a whole bunch of other problems in the way, since no one can agree with consciousness actually is, and it also doesn't account for rocks etc. So maybe the answer is "the experiences of an individual."

But even that isn't sufficient. (Taking for granted that there is a real shared physical world we all interact with.) That definition relies on the existence of an observer (which I'm sure the medievals would happily say is God, but let's just not for now). But if there's a rock, and it goes through millions of years of being a rock, getting picked up or moved by tectonic plates or buried in the dirt, never seen by any person or animal, it seems silly to claim that the rock can't exist or is interchangable with other rocks. A person picking it up doesn't give the rock individuality - they only happen to be the first one to notice the individuality that already exists. 

I'm tempted to skip ahead and be like, WELL, any individual is only our conceptual grouping of atoms based on how we perceive them, where there are no actual physical divides except for the placement of electrons leading to different substances which don't fit together and therefore form a physical barrier to movement for some other substances, etc etc, which admittedly I am not an expert on but makes sense to me. But that might be a bad faith argument because we're talking about these individuals that we implicitly agree do exist as individuals.

Maybe it's two separate questions though.

1) How do I, using sensation, distinguish individuals I meet? That is, how can I support my assumption that other people all have separate identities and experiences from my own? And how do I make this same distinction among non-humans? 

This question seems to be more about psychology - object permanence, how we project our own sensory experiences and mental states onto other people to predict how they'll act, all that stuff. 

2) How do I know that I (my internal state/conception of myself) am unique (a member of my species but not the definition OF my species, an example OF an _  person but not the model of all _ people)?

This one also seems psychological, but more in that dualism way, where we can't really prove that this is true but it seems to be part of how we understand the world in the first place. 

But I'm not sure about this. 

Peter Adamson on 26 July 2022


Those are some interesting points, but not quite about the same issue. Gilbert's question (and the problem of individuation in general) is: what makes something to be an individual in objective reality? It is then a further question whether we are able to tell the individuals apart. The Stoics gave a nice example here: I show you two eggs of the same size, A and B, and then just one of the two eggs: you wouldn't be able to say which egg it is, but that doesn't mean the eggs are not individuals. So don't confuse the epistemic question with the metaphysical question.

This is like something that happens with the argument for determinism from present truths: if it is true now that there will be a sea battle tomorrow, that suggests the sea battle cannot fail to occur; and it's not a good solution to say that we don't know whether it is true, because its truth is independent of our knowledge.

Add new comment

The content of this field is kept private and will not be shown publicly.