Substance and Hypostasis in the Trinity (at The Smithy)
On the Trinity (at Maverick Philosopher)
Reply to the Maverick Philosopher (at The Smithy)
Some Questions about the Trinity Distinguished (at The Maverick Philosopher)
Contradiction in the Trinity? (at The Smithy)
I am very much with Michael here, and have been known at times to be a bit sharper than I intended in conveying the point. The fundamental problem I have with most of the work done by philosophers of religion on the subject, and certainly since Richard Cartwright's famous essay, "On the Logical Problem of the Trinity" is that they clearly and demonstrably start in the wrong place for an inquiry of this sort. The usual procedure is to take some sort of variation of the Quicunque Vult and boil it down even further to some summary like that found in Cartwright's essay, or in Vallicella's post on various questions. This is a shockingly bad start to analysis. The Quicunque Vult is not a dogmatic definition, nor is it a close analysis, being merely a catchy summary; if you are Eastern Orthodox you are in no way committed to it, if you are Catholic you are only committed by the Bull of Union with the Armenians to holding that it is compendious and suitable for basic catechetical purposes; and if you are Protestant, of course, your mileage will vary, but you are definitely going to have weaker commitments to it as an accurate statement of the doctrine than Catholics do. So we are already starting our analysis of the doctrine of Trinity with a secondhand summary of it. Never mind how good, or memorable, it is: this is a flaw in the beginning: it means that if you conclude that the doctrine is inconsistent, then you aren't in a position to tell whether your analysis identifies a problem with Trinitarian doctrine or is an artifact of the particular language used in the Quicunque Vult, which itself was simply a simplified summary. It gives the gist, but a 'gist' is not adequate for serious analysis. One might as well do philosophy of quantum mechanics using a description of photons from a middle school textbook.
Moreover, the flaws spread out farther from here. Often, as I said, this Quicunque-Vult-type summary is itself further summarized, without careful regard for any context, whether catechetical, liturgical, or historical. This is a flaw again: it means that you aren't in a position to tell, if you conclude that it is inconsistent, whether the inconsistency derives from the original or is an artifact of your particular way of boiling it down even further. There are ways to minimize this problem, but they are rarely seen.
Even if we set aside both of these problems, however, we are still faced with a more serious problem. Suppose we assume that these simplified summaries of a simplified summary retains, with full precision, an exactly accurate characterization of the doctrine. We are still faced with the problem that it needs also to compress, without significant loss of meaning, all the relevant content of the original doctrine. Suppose we take a summary like Cartwright's, viz.,
(1) The Father is God, the Son is God, the Holy Spirit is God.
(2) The Father is not the Son, the Son is not the Holy Spirit, the Father is not the Holy Spirit.
(3) There is exactly one God.
The problem is that this is a poor summary of the doctrine of the Trinity. The Church Fathers did not merely say God is one, they said in what way He is one. They did not merely say that the Father is not the Son, they talked at great length about why we whould believe He is not, and in what, precisely, the distinction lies. It is not difficult to rough up a more accurate characterization of the doctrine even along exactly the same lines as this summary; I once did it myself, a few years ago. Better versions are possible. But even these all fail to do what any serious discussion of the Trinity should do, and thus are starting at the tail-end. To start an analysis correctly, you need to start at the fundamentals, and here that means focusing on the processions, because the reasons for accepting that there are processions in God are the reasons for accepting the doctrine of the Trinity, and each of the points in these crude simplified summaries can only characterize the doctrine of the Trinity if it is understood to summarize some fact about the divine processions. Anyone who claims to discuss whether the doctrine of the Trinity is consistent without addressing first, foremost, and fully the doctrine of divine processions, and the reasoning underlying it, is someone who simply does not understand what the doctrine of the Trinity is.
As a tangent, I've sometimes wondered if this beginning at the wrong end is partly responsible for the shockingly heavy-handed treatment of analogies in this context. When someone claims that the doctrine of the Trinity can't be consistent because three things can't be one, and St. Patrick responds with the shamrock, three leaves in one leaf, this is a perfectly good answer, considered formally. It addresses the objection completely and elegantly by showing that the objection, as stated, is thoroughly silly: there are plenty of ways in which things can be three and one, and therefore you will have to make your objection much more precise than this if you really want to argue that the doctrine of the Trinity is inconsistent. It shows that the objection is an attempt to use a railroad tie to do a laser's work. But philosophers of religion these days often take the analogies materially; and so we get disquisitions on how the shamrock illuminates nothing about the doctrine of the Trinity because God is not like a three-leaf clover. Obviously God is not like a three-leaf clover; any sensible analogue you might choose is going to be something that God is very unlike. It is also not to the point. Even an analogy as crude and unsophisticated as a shamrock illuminates the doctrine by showing that it is clearly consistent up to a certain level of description. But of course even when we deal with more sophisticated analogies at deeper levels of analysis it is possible to stay heavy-handed in discussion of analogies in other ways. Michael gives a good example from Cartwright:
The heretical conclusion follows, by the general principle that if every A is a B then there cannot be fewer B's than A's. This principle, I claim, is evident to the natural light of reason. Thus, if every cat is an animal, there cannot be fewer animals than cats; if every senator from Massachusetts is a Democrat, there cannot be fewer Democrats than senators from Massachusetts. Just so, if every Divine Person is a God, there cannot be fewer Gods than Divine Persons.
But, as Michael notes, there is a world of assumption packed into this "just so," which requires that the analogy be formally exact among all the cases -- the doctrine of the Trinity is convicted for not treating God exactly like cats on this point. But the fact that if every cat is an animal there cannot be fewer animals than cats does not establish that this is so for every A that is a B, any more than the fact that every pair of geodesics on a Euclidean plane that are equidistant somewhere are equidistant everywhere proves that every pair of geodesics of any sort are. This is a crude handling of analogy, and not at all illuminating of anything.
I could extend the list, but the point, I think, is made: that discussions of the Trinity in contemporary philosophy are crude and backwards, not the sophisticated analyses they are put forward as being. Just how egregious an offender a particular philosopher is varies greatly; some are so much better than others that they are like fresh air -- and I would count both Cartwright and Vallicella in this category, because despite the fact that I think Cartwright goes wrong at so many points, I have seen much, much worse. But they are generally quite unsuited to the task of dealing with the Trinitarian doctrine itself; and, in fact, the closest they get to actually talking about it is when they talk about something as vaguely like it as a Dick and Jane book is vaguely like a novel.