Leftow 1: “Anti Social Trinitarianism”

Brian Leftow is recognized as one of the most important living Christian philosophers. Formerly of Fordham University in NYC, he now holds the prestigious Nolloth Chair of the Philosophy of the Christian Religion at Oriel College, Oxford. See Trent Dougherty’s comments here for a list of some of his publications. In person, Leftow is very pleasant and interesting, and his sense of humor also comes out in this wide-ranging interview, first posted on Prosblogion by Trent. In print, he’s a uber-sophisticated, latter-day medieval – I think he’d take that as a compliment! 🙂 Or maybe the lost love child of Aquinas and David Lewis. OK, I’ll stop. My point is: he knows how to put an original argument together.

Leftow’s essay “Anti Social Trinitarianism” (in Stephen T. Davis, Daniel Kendall, and Gerald O’Collins, eds., The Trinity (New York: Oxford University Press, 1999) – linked at the lower right of this blog’s main page) is commonly recognized among Christian philosophers as one of the most important pieces on the subject recently (and I’d say, ever) written. His main point is that social trinitarianism “cannot be both orthodox and a version of monotheism.” (p. 203) I’ll come back to this challenging piece some time when I get around to discussiong social trinitarian theories. Here, I’m going to cover only the start of the essay, where Leftow sets the agenda for his own “Latin” trinitarian theory (LT).

Here’s what he says about his own preferred version of the doctrine:

In LT, there is just one divine being (or substance), God. God constitutes three Persons, but all three are at bottom just God. … [as Aquinas says,] ‘…God begotten receives numerically the same nature God begetting has.’
To make Aquinas’ claim perfectly plain, I introduce a technical term, ‘trope’. Abel and Cain were both human. So they had the same nature, humanity. Yet each also had his own nature, and Cain’s humanity was not identical with Abel’s… A trope is an individualized case of an attribute. Their bearers individuate tropes: Cain’s humanity is distinct from Abel’s just because it is Cain’s, not Abel’s.
With this term in hand, I now restate Aquinas’ claim: while Father and Son instance the divine nature (deity), they have but one trope of deity between them, which is God’s… bearers individuate tropes. If the Father’s deity is God’s, this is because the Father just is God…(203-4, original emphasis in italics)

This part seems clear enough. He’s drawing a contrast; he goes on to point out (204-5) that whereas social trinitarians posit three tropes of divinity, because they posit three numerically distinct Persons, LT posits only one trope of divinity, as it holds that the Father just is (that is, is numerically identical to) the Son (etc.). If this was all he’d said, then I’d say it was modalism, and moreover a kind which is refutable. What would he say, I wonder, to the following argument?

1. For any X and Y, if they share a trope of any property, then X = Y.
2. The Father and Son share a trope of divinity.
3. The Father is numerically identical to the Son. (1,2)
4. Whatever is true of the Father is true of the Son (and vice versa). (3 & Leibniz’s Law)
5. The Son was crucifed. (New Testament)
6. The Father was crucified. (4,5)

Leftow seems committed to 1 & 2. 3 follows from them. 4 is self-evident. Hence, he’s committed to 5 & 6. But this shows that at least one of 1-2 is false – LT just won’t fly.
This doesn’t settle the matter, though, for Leftow goes on to say some other things, which cast doubt on whether he actually accepts 1 & 2, things which I think he develops in a later paper. Immediately following the above passage, he continues:

In LT, then, the numerical identity of God is secure, but one wonders just how the Persons manage to be three. For in LT, the Persons are distinct but not discrete. Instead, LT’s Persons have God in common, though not exactly as a common part. In [Social Trinitarianism], the Persons are distinct and discrete. There is nothing one would be tempted to call a part they have in common. What they share is the generic divine nature, an attribute. (204)

I’m not sure what to make of this passage. But I believe that what he had in mind was something like this (though I don’t think he’d want to use these terms). The Father and Son are both modes of one and the same God. That God is self-identical entity, and has only one trope of divinity, and the Father and Son equally “have” him in the sense of being ways that he lives or exists. The both “are” (are modes of) him, but neither is identical to him; a mode is never, or at least needn’t be, identical to that of which it is a mode. So Father and Son are numerically distinct modes, but they’re modes of one and the same thing, God. So Father and Son are, as he says, “distinct but not discrete”. If this reading of Leftow’s paper is right, then he denies premise 2 of my objection-argument above – neither Father nor Son is the bearer of the trope of divinity. Rather, they’re both modes of the bearer (God) of the one trope of divinity.

If this is right, then in my view, there are still plenty of reasons to reject it. Presumably, on this theory both Father and Son are events. And arguably, events can’t be in loving relationship with one another – only persons (personal substances/entities/individuals) can – and persons are not reducible to events. In general, theological incoherence looms at every turn, once we accept any kind of S-modalism. Further, if being “divine” means being identical to a god, to a certain kind of individual, then in that sense he’s denying that either Father or Son is divine.

Again, in fairness to Leftow, his main purpose in this essay is to bring on the pain for social trinitarians – he isn’t trying to fully develop what he calls LT here. But he does return to that positive task with a vengeance in a later paper, which we’ll look at next time.