I am currently reading Thomas Mccall’s Which Trinity? Whose Monotheism? This is the best section of the book. He deals with philosopher Brian Leftow, who openly says there are “personal parts” in God (Leftow, “A Latin Trinity,” 308, quoted in McCall 114). Indeed, “they add up to the life of the one God” (“Modes without Modalism,” 375). This is hard to square with any account of divine simplicity, but there are bigger problems.
If Leftow is representative of LT, then LT is guilty of positing a Quaternity. So far we have
(1) there are personal parts that add up to the one God
(2) “There is either a fourth instance of divinity,
(2a) or there is not” (McCall 115).
If (2 is true, it is either a divine person or it is not a divine person. Orthodoxy rules out its being a divine person. Logically, that wouldn’t hold, either. A person usually isn’t part of another person (except in the womb, I suppose). As McCall notes, “When three persons add up to another [something], it usually isn’t a person.”
It’s not clear how LT can say “God is a person.” How can that even be monotheistic? But if God = Trinity = collection of persons, then this is just simply Social Trinitarianism anew. (Indeed, one can say at this point that the One-Many dialectic is feeding itself upon each pole of the dialectic).
(3) Per Leftow, maybe he means ‘The Trinity is a Person.’
McCall says (3) is what Leftow’s “Rockettes” analogy suggests (think of Jane entering different parts of time simultaneously; from our perspective Jane can only enter the past, then the present, then the future. But from Jane’s (God’s?) perspective, all of these moments are simultaneous. But this means the person “plays three different roles in three different streams of events” (Mccall 116). Thus,
(4) We have three persons, plus a Trinity who is also a person. A Quaternity.
We come back to Leftow’s part-whole relation. If there are “parts” in God, then we have to ask “Of what are they parts?” This entails (5) and (6). The only possible way out is
(5) Leftow doesn’t represent Latin Trinitarianism
That’s a tall claim, though.