What is the Difference Between a Substance and a Supposit?

I need to answer three questions.  This post addresses the first.

1. What is the difference between an Aristotelian primary substance and a supposit (hypostasis, suppositum)?

2. Is there any non-theological basis for this distinction? 

3. If the answer to (2) is negative, is the addition of suppposita to one's Aristotelian ontology  a case of legitimate metaphysical revision or a case of an ad hoc theoretical patch job?  According to Marilyn McCord Adams, "Metaphysical revision differs from ad hoc theoretical patching insofar as it attempts to make the new data systematically unsurprising in a wider theoretical context." ("Substance and Supposits," p. 40)

The First Question

By 'substance' I mean an Aristotelian primary substance, an individual or singular complete concrete entity together with its accidents.  Among the characteristics of substances are the following: substances, unlike universal properties, cannot be exemplified or instantiated; substances, unlike accidents, cannot inhere in anything; substances, unlike heaps and aggregates, are per se unities.  Thus Socrates and his donkey are each a substance, but the mereological sum of the two is not a substance.

Now what is a supposit?  Experts in medieval philosophy -- and I am not one of them, nota bene -- sometimes write as if there is no distinction between a substance and a supposit.  Thus Richard Cross: "Basically a supposit is a complete being that is neither instantiated or exemplified, nor inherent in another."  ("Relations, Universals, and the Absue of Tropes," PAS 79, 2005, p. 53.) And Marilyn McCord Adams speaks of Socrates and Plato as "substance individuals" and then puts "hypostases or supposits" in apposition to the first phrase. (PAS 79, 2005, p. 15)

My first question, then is:  Is there any more-than-verbal difference between a substance and a supposit, and if so, what is it?

One answer that suggests itself is that, while every substance has a supposit, some substances have alien supposits.  (I take this phrase from Adams, p. 31 et passim.)  A substance has an alien supposit iff it is not its own supposit.  I understand Aristotle to maintain or at least be committed to the proposition that every (primary) substance is essentially its own supposit.  If so, then no substance is possibly such as to have an alien supposit.  If alien supposition is metaphysically or broadly logically possible, however, then we have a ground for a more-than-terminological distinction between substances and supposits.  Whether the converse of this conditional holds is a further question.  For it may be that there is a ground for the distinction even if alien supposition is not possible.

Incarnation, Trinity, and the separated soul's survival between death and resurrection are theological examples of alien supposition.  Whether there are non-theological examples is a further, and very important question, one the answer to which has consequences for questions (2) and (3) above.

The Incarnation is an example of alien supposition as I will now try to explain.

The orthodox view is that God the Son, the second person of the Trinity, the Word, becomes man in Jesus of Nazareth.  Although the Word becomes flesh and dwells among us as we read in the NT, the Word does not merely assume a human body, nor does it acquire a universal property, humanity; the Word assumes a particularized  human nature, body and soul.  The eternal Word assumes or 'takes on' a man, an individual man, with an intellectual  soul and and animal body.  But now a problem looms, one that can be articulated in terms of the following aporetic tetrad:

a. A person is a (primary) substance of a rational nature. (Boethian definition)

b. There is only one person in Christ, the Word, the Second Person of the Trinity.  (Rejection of the heresy of Nestorius, according to which in Christ there are two persons in two natures rather than one person in two natures.)

c. The individual(ized) human nature of Christ is a primary substance of a rational nature.

d. Every (primary) substance is its own supposit, which implies that every substance of a rational nature has its own personhood.

The tetrad is logically inconsistent: any three limbs taken in conjunction entail the negation of the remaining one.  Thus the conjunction (a) & (c) & (d) entails the negation of (b).  The solution to the tetrad is to deny (d).  One does this by maintaining that, while the individualized human nature of Christ is a substance, it is not a substance that supports itself: it has an alien supposit, namely, the Second Person of the Trinity.

If the Incarnation as Chalcedonian orthodoxy understands it is actual, then it is possible.  If so, alien supposition is possible, which straightaway entails a distinction between substance and supposit: while every substance has or is a supposit, not every substance has or is its own supposit.  The individualized human nature of Christ is a supposited substance but is not a supposit.

Let me now say a bit about the Trinity.  Here too a problem looms that can be cast in the mold of an aporetic tetrad.

a. A person is a (primary) substance of a rational nature. (Boethian definition) 

e. There are exactly three divine persons, Father, Son, Holy Ghost .  (Rejection of 'Quaternity')

f.  The individualized nature of God is a primary substance  of a rational nature.

d. Every (primary) substance is its own supposit, which implies that every substance of a rational nature has its own personhood.

Again, the tetrad is inconsistent, and again the solution is to reject (d) by saying that, while the individualized divine nature is a primary substance, it is not one that supposits itself: it has three alien supposits, Father, Son, and Holy Ghost.

The Son is thus the alien supposit of both God's divine nature and Christ's human nature.

My first question concerned the difference between a substance and supposit.  My tentative answer is that  while only substances can be supposits, there are substances that are not their own supposits nor are they supposits for anything else, an example being the individualized human nature of Christ.

Is there a non-theological basis for the distinction?  if not, then the suspicion arises that the distinction is purely ad hoc, crafted to save tenets of orthodox Christian theology.  But this is a question for another occasion.

Related articles

Garrigou-Lagrange on Thomas on the Divine Persons as Subsistent Relations

Trying to Understand Ockham on Supposita in Light of the Incarnation

Mereology and Trinity: Response to Wong

E. J. Lowe on the Distinction Between Constituent and Relational Ontology

Comments

[John]

Let me preface these remarks with the disclaimer that I am not an expert - or even particularly knowledgeable - in medieval philosophy.

That said, I have some questions about your set up, Bill. You take a substance to be "an Aristotelian primary substance, an individual or singular complete concrete entity together with its accidents". You give as examples Socrates and his donkey. But here we must be careful. Socrates - the substance - is indeed an individual, a complete concrete entity, but *not* taken together with his accidents. In Metaphysics Z.1, Aristotle is careful to distinguish between the "the substance and the particular" and "the walking thing and the sitting thing and the healthy thing that is" (1028a24-28; Bostock's translation). The substance is that which underlies these others. The substance taken together with its accidents, then, is not the primary substance; it is the accidental unity such as the sitting Socrates or the musical man.

You also claim that Aristotle maintains, or is committed to, the view that "every (primary) substance is essentially its own supposit". But I am not sure this is correct either, given your understanding of what a primary substance is. (I am very unsure of what I'm about to say, because I am still unclear on what a supposit is.) At the beginning of Z.6, Aristotle inquires into whether a thing "is the same as, or different from, what being is for it" (1031a15-16). His answer is that in the case of things "which are spoken of coincidentally", the two "would seem to be different" (1031a19-20). By contrast, in the case of things "spoken of in their own right", these he tells us are the same as what being is for them (1032a4-7). This chapter of Z (and the chapters that precede it, in which Aristotle makes some "logical remarks" about essence) is difficult to understand. But on at least one way of understanding Aristotle here, things that are spoken of in their own right are substantial forms, not individual substances like Socrates. Thus, in De Anima II.1, Aristotle says that "[w]e should not then inquire whether the soul and body are one thing" because "although unity and being are spoken of in a number of ways, it is of the actuality that they are most properly said" (412b7-12; Lawson-Tancred's translation). And the actuality, of course, is identified with form.

Much of this is extremely controversial. It's telling that in Z.6, when Aristotle discusses things that are spoken of coincidentally, he focuses on compounds of substance and accident, not matter and form. Nevertheless, what I've just sketched is not absurd. If it is correct, however, then there might be a way of showing that there is a non-theological basis for the distinction between a substance and a supposit, because - if I am right - it is false that every substance is essentially its own supposit. Alien supposition would then be possible in the broadly logical sense.

[BV]

Thanks for your comments, John.

But I don't agree. There are of course accidental unities. There was some discussion of them on this weblog in the fall of 2011. This from a 19 Oct 2011 post:

When Socrates sits down, seated-Socrates comes into existence. When he stands up or adopts some other nonseated posture, seated-Socrates passes out of existence. This 'kooky' or 'queer' object is presumably a particular, not a universal, though it is not a substance. It is an accidental unity whose existence is parasitic upon the existence of its parent substance, Socrates. It cannot exist without the parent substance, but the latter can exist without it. The relation is like that of a fist to a hand made into a fist. The fist cannot exist without the hand, but the hand can exist without being made into a fist.Though seated-Socrates is not a substance it is like a substance in that it is a hylomorphic compound: it has Socrates as its matter and seatedness as its form. As long as Socrates and seated-Socrates exist, the relation between them is accidental sameness, a relation weaker than strict identity.

Accidental sameness is not strict identity presumably because the former is not governed by the Indiscernibility of Identicals. Clearly, Socrates and seated-Socrates do not share all properties despite their sameness. They differ temporally and modally. Socrates exists at times at which seated-Socrates does not exist (though not conversely). And it is possible that Socrates exist without seated-Socrates existing (though not conversely).

Are Socrates and seated-Socrates numerically the same? They count as one and so they are one in number though not one in being. So says Aristotle according to Rea. After all, if Socrates and Alcibiades are seated at table we count two philosophers not four. We don't count: Socrates, seated-Socrates, Alcibiades, seated-Alcibiades.

So, John, if you are saying that there is a distinction between Socrates the substance and seated-Socrates, which is not a substance, but an accidental unity, then I agree, and I agree that this can be found in Aristotle. But surely at any given time Socrates cannot exist without some set of accidents or other. So the complete individual is Socrates together with his accidents.

[BV]

Unfortunately, John, I can't follow your last two paragraphs. For example, I don't know what this means: >> At the beginning of Z.6, Aristotle inquires into whether a thing "is the same as, or different from, what being is for it" (1031a15-16).<<

[John]

If there is a distinction between Socrates the substance and seated-Socrates, which is not a substance, and if the complete individual is Socrates together with his accidents, doesn't it follow that the complete individual is not identical to the substance? Consider seated-Socrates. He is, as you point out, a hylomorphic compound, with Socrates (the substance) serving as matter and the accident being-seated serving as form. Suppose we call this the complete individual Socrates. It cannot be strictly identical with Socrates (the substance), any more than a hylomorphic compound can be strictly identical with its matter. I may be mistaken, but this can be generalized to the complete individual understand as Socrates together with *all* his accidents. Socrates is not strictly identical to any of those accidental unities, and so is not strictly identical to what you're calling the complete individual.

I agree that Socrates (the substance) cannot exist without some set of accidents or other, but I don't believe it follows from this Socrates (the substance) is strictly identical to what you're calling the complete individual. Exactly the same problem comes up in the Categories, where Aristotle tells us that nothing else would exist if there were not any primary substances, but he never seems to realize that there could not be a primary substance without any qualities, or quantities, and so on. Exactly how to understand Aristotle's notions of priority in nature and priority in being, and how to fit them with his view that substance is prior in nature and prior in being, is (of course) controversial. But I don't think my point about distinguishing between substances and accidental unities commits me to the view that Socrates could exist without some set of accidents.

At this point, I am not sure that we are disagreeing. Perhaps I am being thrown by your use of the phrase 'complete individual'. The point I want to make is simply that what you're calling the complete individual is not a substance because it is an accidental unity of a substance and some set of accidents.

With respect to my last two paragraphs, Bostock renders the Greek 'to ti en hekastoi einai' as 'what being is for a thing', and 'to ti en einai' as 'a what-being-is' (or, perhaps better, "the what-it-is-to-be"). As I understand it, we can (somewhat informally) translate these phrases as 'essence'. So, the question with which Aristotle begins Z.6 is: is a thing identical to its essence? The view that things spoken of in their own right are identical to their essences is what Michael Loux calls "The Z.6 Identity Thesis".

[BV]

Let S be a primary substance, and A an accident that inheres in A.

Do you agree with each of the following and that they are collectively consistent?

1. S can exist without A. I.e., it is possible that S exist & A not inhere in S. Example: it is possible that Socrates exist but not be bearded.

2. A cannot exist without inhering in some substance or other.

3. A cannot exist without inhering in S. Thus the beardedness in Socrates cannot inhere in any other substance, or migrate to any other substance.

4. S cannot exist without having some accidents or other.

[Elliott Crozat]

Bill,

Are you are using supposit as a synonym for hypostasis? If so, distinguishing between hypostasis and substance could shed light on the possible difference between supposit and substance. There might be two distinctions to consider.

First, some Hellenic/Hellenistic philosophers apparently thought of hypostasis as a substance of a rational/personal nature. As you wrote, a primary substance is an individual or singular complete concrete entity together with its accidents. Socrates and his donkey are each a substance. But Socrates is a hypostasis. His donkey is not. In this sense, hypostasis is a kind of substance.

Second, as noted above, some in the tradition apparently used hypostasis to mean “substance of a rational/personal nature.” Some also seem to have used hypostasis to mean “property-bearing substance.” This difference in usage suggests a distinction between a hypostasis that is actually personalized and a hypostasis that is potentially but not actually personalized. So Socrates would be a personalized hypostasis and the donkey would not. In this sense, person is a kind of hypostasis.

I’m not well-versed in the history of Platonism, but some Platonists/Neoplatonists seem to have used the term hypostasis to mean a rational/personal substance. Philo of Alexandria may have thought in this way. Plotinus and Proclus arguably thought in this way and believed that Plato did too - or at least that Plato did so implicitly. Plotinus seems to have thought that the Nous hypostasis eternally derives personality/rationality from the One. So maybe in Plotinus we have an example of a thinker who conceived of a hypostasis (Nous) that is personalized by another (the One).

If this view of the Greek tradition is tenable, and I’m not sure it is, the distinction between hypostasis and substance arguably exists outside the thinking of the early church.

[John]

Bill,

I agree with both 1 and 2, at least as interpretations of Aristotle. He is clearly committed to both; I am certainly committed to 1 and am not sure about 2. I am not sure what I think about 3. It is controversial whether Aristotle (at least in the Categories) is committed to 3. Although the standard interpretation is that he is, recently a number of scholars have challenged this. I also accept 4, and I assume that Aristotle would have as well. Finally, it seems clear that these four propositions are consistent with one another.

Let me try (briefly!) to make my point one last time, because I anticipate an objection from you given your last post. My claim is the following: Socrates (the substance) is not strictly identical to Socrates (the complete individual). The argument is as follows:

(A) The complete individual Socrates is a hylomorphic compound of matter and form (Premise).
(B) The substance Socrates is the matter of the complete individual Socrates (Premise).
(C) For all x and for all y, if x is a hylomorphic compound and y is the matter of x, then x is not strictly identical to y.
Therefore,
(D) The complete individual Socrates is not strictly identical to the substance Socrates.

It seems to me that my conclusion, (D), can be true even if your propositions (1)-(4) are true. What tension there may be would seem to come from 4, but even if the substance Socrates cannot exist without having some accidents or other, it does not follow that it is identical to the complete individual Socrates.

[BV]

Elliot,

Suppositum = hypostasis. The only difference is that between Latin and Greek. This is in line with the medieval specialists I am now studying.

[BV]

John,

How can you not be sure about (2)? You don't believe in Transubstantiation, do you?

I will try to respond to the rest of your comment tomorrow.

[John]

If by 'accident' you just mean 'accidental property', then I am not sure about (2) because I am not sure about the following claim:

A property can exist only if it is instantiated by some object.

If by 'accident' you don't mean 'accidental property', then I suppose I am sure that (2) is true.

Maybe it should be obvious in the context of a discussion of Aristotle that by 'accident' you do not mean 'accidental property', in which case it should be obvious that (2) is true. But I don't think that's obvious. It seems to me that it would obscure a lot of the debate between Plato and Aristotle. on the nature of properties.

[BV]

But surely, John, if we are talking about Aristotle and the scholastics who follow him, then 'accident' cannot possibly mean 'accidental property' in the sense in which an accidental property could exist uninstantiated.

'Accident' is a terminus technicus in an Aristotelian context. I think you are missing that.

The debate between Plato and Aristotle is a debate about properties and property-possession. Aristotle maintains that a property such as whiteness is an accident; Plato denies that.

[BV]

John,

If what you are saying is that Socrates together with his accidents is not strictly identical to Socrates taken in abstraction from his accidents, then I agree.

But I still insist that it is only Socrates together with his accidents that is a complete concrete individual primary substance.

Note also that Socrates taken in abstraction from his accidents is not prime matter but a compound of prime matter and substantial form.

Furthermore, I am not interested in Aristotle exegesis, but the question whether there is a tenable distinction between substance and supposit.

[Elliott Crozat]

Thanks, Bill. Your first question might be answered somewhere in Platonic-Aristotelian thought. But I understand the preference to avoid exegesis. If a relevant distinction exists, identifying and evaluating it would be the priority.

[John]

Bill,

The reason I introduced some passages from Aristotle was because I thought that they were relevant to the question of whether there is a tenable distinction between substance and supposit. In particular, I thought that Aristotle's "logical remarks" in Z.4-Z.6 (but especially Z.6) were relevant to that question because (a) he there claims that only those things spoken of in their own right are identical to their what-being-is, or essence, and (b) he seems to think that things spoken of in their own right are substantial forms. My thought was that this view would imply the denial of the claim that every substance is essentially its own supposit. If you find this too obscure to be of use, then that's fine. But it was not my intention to begin a debate about Aristotle exegesis.

That said, I *am* saying that Socrates taken together with his accidents is not strictly identical to Socrates taken in abstraction from his accidents. But that point is obvious. What I am adding is this: Socrates taken together with his accidents is not a substance, but an accidental unity of a substance and some accidents. So I deny your claim that "it is only Socrates together with his accidents that is a complete concrete individual primary substance". Socrates together with his accidents may well be the only complete concrete individual, but he is not a primary substance. Nor is he prime matter; as you say, he is a compound of prime matter and substantial form, although in conjunction with his accidents he plays the *role* of matter in the accidental unity between him and his accidents.

This would seem to be a debate about Aristotelian exegesis, so I'll leave it there and not continue to hijack your discussion. As I said, I thought the discussion in Z.4-Z.6 would prove relevant to that discussion, but it would seem that I was mistaken on that score, for which I apologize.