We have been discussing the question of the logical consistency of the orthodox doctrine of the Trinity. Dr. Lukas Novak (Charles University, Prague) has offered a solution to the consistency problem that relies crucially on the notion of a suppositum or supposit. If I have understood him, his suggestion is that there is nothing logically problematic in the suggestion that the individual divine nature has three supposits, The Father, the Son, and the Holy Spirit.
It is worth reminding ourselves that any solution to the consistency problem will depend on one's background logic and general ontology. And the same holds if one decides that the problem is insoluble.
But being none too clear about what a supposit is supposed to be, I asked Novak if he could define the term and how it stands vis-a-vis such terms as 'bare particular' (Gustav Bergmann) and 'thin particular' (David Armstrong). He responded as follows:
Ad 4) X is a suppositum iff X is something endowed with individual nature and suppositality, that is, X is both uninstantiable and incommunicable to a subject (and not a part nor an aggregate).
Ad 5) It is better said that Socrates' humanity inheres in Socrates, who is a suppositum. Suppositum is not a bare or thin particular. If there were bare particulars, they would probably be classified as supposita, but classically supposita are not considered to be "thin" or "bare" – they have their rather "thick" essences or natures de re necessarily. Socrates is identical to Socrates' suppositum. Socrates' humanity inheres in Socrates and is a metaphysical constituent of Socrates. Socrates' humanity plus his suppositality makes up Socrates. Neither Socrates' humanity nor his suppositality are entities in their own right, they are just aspects or metaphysical constituents of Socrates. So I use "inhere" here as _not_ implying any particular kind of distinction between the nature and the suppositum.
I am afraid that this explanation does not clear up the notion of suppositum for me. The definition is tolerably clear if a suppositum is something like a bare or thin particular. But then we are told that supposita are not bare or thin particulars. Why not? Because they have essences (natures) of de re necessity. So far, so good: bare particulars are bare in that there is nothing in the nature of a bare particular to require it to have any particular set of properties. Bare particulars, being mere individuators/differentiators, can combine 'promiscuously' with any set of properties. Not so with supposita on Novak's account. But now Novak makes three claims that I cannot see are consistent:
1. Socrates is identical to Socrates' suppositum.
2. Socrates' humanity is a metaphysical constituent of Socrates.
3. Socrates' humanity plus his suppositality make up Socrates.
One problem concerns the meaning of (3). Does it mean
3*. Socrates' humanity plus his suppositum make up Socrates?
(3*) has a clear meaning but is not consistent with (1) and (2). For if S is identical to his suppositum, then S cannot be identical to S's suppositum + S's humanity. A thing cannot be identical to a proper part of itself.
But it all depends on what we mean by 'identity.' I take identity to be an equivalence relation (i.e., one that is reflexive, symmetrical, transitive) which satisfies the Indiscernibility of Identicals and the Necessity of Identity (Necessarily, for any x, y, if x = y, then necessarily x = y). Perhaps Novak understands something else by 'identity,' or it could be that he accepts what I just wrote but adds to the mix one or more contingent sameness relations. I await his clarification.
Another problem is that 'suppositality' is given a purely negative explanation: It is the feature of being both uninstantiable and incommunicable to a subject. What is it positively? And to what does it apply? Socrates' suppositum? Socrates? Both? The feature does apply to bare particulars, but they are not supposita.
We are told that "Neither Socrates' humanity nor his suppositality are entities in their own right, they are just aspects or metaphysical constituents of Socrates." I find this highly problematic. First let me say that I have no argument with the notion of ordinary concrete particulars being composed of metaphysical, or as I prefer to say, 'ontological' constituents. I make heavy use of them in my book A Paradigm Theory of Existence (Kluwer 2002). But it is difficult to see how a metaphysical constituent could be a mere aspect of the thing of which it is the constituent. It is a bit like saying that the stones of which a stone wall is composed are 'aspects' of the wall. 'Aspect,' I presume, is from ad-spectare, and that suggests that aspects are relative to a viewer or thinker. Perhaps Novak will respond by saying that these aspects are 'amphibious' : theya re both in the mind and in the thing.
Finally, Novak tells us in effect that there is no distinction of any kind between nature and suppositum. I am afraid this makes no sense to me at all. Surely there must be some kind of distinction here! Otherwise, nature = suppositum. If so, in the case of the Trinity, it cannot be that one nature has three distinct supposita. What's worse, if Socrates is identical to Socrates' suppositum, and the latter is identical to his nature, then Socrates ends up an ontologically structureless 'blob' to use a term David Armstrong employs.
Leave a Reply