This weekend I chaired a session at the Eastern Regional Meeting of the Society of Chistian Philosophers in which Dale Tuggy put Reid and Hume on the psychologists couch. It was an interesting exercise in moral psychology. It also reminded me to post on the Trinity, since Dale is a detractor of social Trinitarianism (ST) of which I am an adherent. Dale has a 2003 Philosophia Christi piece criticizing my main man Ed Wierenga's ST paper which appeared in Faith and Philosophy in 2004 (the publication order is explained by the fact that Dale commented on Ed's paper at a conference before either were published).
I was not able to join the discussion here which Bill started but I think the discussion only briefly touched on the real issue.
To my mind, Tom made just the right move in that discussion: God is not a person, though he is personal. I think Bill's response is too quick: "If the personality is divided among the Persons, then the one God is subpersonal." I question whether "divided among" is the right way to think about it and I question whether even on that interp God comes out as subpersonal. It has always driven me crazy when Plantinga says that God is a person. He very frequently defines theism as the belief that "there is such a person as God." I've always cringed at this and I think in every text I have where he says that I've scrawled in he margins "No! God is personal!"
Social Trinitarians are *not* saying that the personality of the Godhead is divided among the divine persons in the same way that the personality of my Logic class is divided among my students and I. The relationship between the divine persons and each other and with the Godhead is much more intimate than that. Can I spell it out precisely? No I cannot (I might be more worried if I could!). But I don't think that's an objection in this context. ST-theorists, like all Trinitarians, will always have more work to do.
I do wish to note that papers arguing against ST tend to neglect of some of the details of Swinburne's 2nd section--"The Traditional Doctrine"--of his Chapter on the Trinity in The Christian God , especially 180-1, 186, 189. What he says there clearly distinguishes the society of persons in the Godhead from ordinary societies. Is the mystery going to disappear? Of course not (and we should be worried if it did!). Still, Swinburne states, in clear terms using standard terminology from analytic philosophy, a property which distinguishes them and which naturally expresses, though in a mind-boggling way, the interconnectedness of the persons of the Trinity. Anti-social Trinitarians will want more, no doubt, but I think it is enough.
Now to the polytheism bit.