The following thoughts occurred to me yesterday, and I wanted to jot some notes down before forgetting them, though I am far from endorsing them. Just something to chew upon. Some philosophers reject Divine Simplicity and certain explications of the Doctrine of the Trinity because such doctrines seemingly involve contradictions. These contradictions arise when the attributes of God and/or Persons of the Trinity are related to one another by numerical identity. Here are some problematic Divine Propositions:
- God = the Triune Godhead
- The Son of God = God
- God = God’s Knowledge
- God = God’s Power
These are problematic, because (1) and (2) seem to suggest that the Son of God = the Triune Godhead, which no orthodox Christian wants to say. Likewise, it prima facie problematic to take (3) and (4) to mean that God’s Knowledge is identical to God’s Power. One solution to this latter problem is to appeal to the doctrine of analogy and say that God’s Knowledge and Power and not the same as the knowledge and power we commonly know about from our everyday experience, so they can be identical. This may be compelling for some, like myself, but for others, I suspect it comes off as appealing to mystery. That is, we don’t really know what we are saying when we say that God has power or knowledge. The former problem is more difficult to resolve. How can we say that the persons of the Trinity are identical to God, but not infer that they are identical to one another, or to the totality of the Godhead? A method to address this is to appeal to the Relative Theory of Identity, devised by Peter Geach. According to this theory, it is an incomplete expression to say that “x is the same as y”. Geach thinks we have to specify the sortal concept by which x and y are the same, that is “x is the same F as y”. This might help us to explain the “The Son of God is the same God as the Father” while also admitting “The Son of God is not the same Divine Person as the Father”. The sortal terms prevent a direct contradiction. Of course, this may pose a problem for absolute simplicity, since it seems like a sortal is kind or type, and “The Son” or “The Father” are tokens of the type. Also, this solution does not seem to help with (1) and (2), since it seems that the same sortal term could be specified. That is “God is the same God (or Divine Substance) as the Triune Godhead” and “The Son of God is the same God (or Divine Substance) as God.” With the same sortals in place, it seems that Leibniz’s laws are in play again, and we should be able to substitute terms salve veritate. A recent discussion got me thinking of a possible solution to these puzzles. A person was arguing against the Identity of Indiscernibles by appealing to Max Black’s Spheres as possible counterexamples. The other interlocutor noted that the issue really isn’t the Identity of Indiscenibles, but the Indiscernibility of Identicals. Just to be clear, the two principles are here:
- (∀x)(∀y)((x = y) ⊃ (∀φ)(φx ≡ φy)) [indiscernibility of identicals]
- (∀x)(∀y)((∀φ)(φx ≡ φy) ⊃ (x = y))[identity of indiscernibles]
The interlocutor seemed to be saying that while (6) may be controversial, it is irrelevant to his problem. Rather, it is (5) which seems to imply that since the Son of God is numerically identical to God, and God is supposed to be Triune, the Son of God must be Triune, where “Triune” stands as some sort of property, attribute, predicate or description. This implies a transitivity among identicals, which I take to be the real underlying problem in these theological discussions. If the orthodox teachings of divine simplicity and the Trinity depend on a notion of numerical identity, and numerical identity is transitive, or admits of substitution, then certain untoward consequences and contradictions result. By transitivity, I mean the following formal expression:
- (∀x)(∀y)(∀z)(((x = y) & (y =z)) ⊃ (x = z)) [transitivity]
So my proposal is to consider whether there is a way to maintain the claim that all of God’s attributes and relations are strict identity claims (rather than relative identity claims, or mere predications) while avoiding untoward inferences. It occurs to me that the indiscernibility of identicals, identity substitution, and the transitivity of identity generally are disrupted in referentially opaque contexts. So, for instance, consider the following:
- I believe that the Boston Strangler = Bobby Orr.
- The Boston Strangler = Albert DeSalvo.
We cannot infer from (8) and (9) that Bob Orr is Albert DeSalvo. Perhaps it is true that Albert DeSalvo has been living under a false identity of Bobby Orr, so “Bobby Orr” and “Albert DeSalvo” refer to the same person. That’s possible, but it is not logically necessary, so truth would not be preserved. This is because “I believe” is a context that is referentially opaque. How does this help us in preserving orthodox theological claims? There are other referentially opaque contexts. One such context that Quine famously argued for is de re modality. In a de re modal claim, one asserts that a certain property, predication, or identity is necessarily predicated of an individual (or property). This is opposed to de dicto modal claims, in which propositions themselves are said to be necessary. So, for instance, a de re modal claim might be something like “Daniel is necessarily an animal” where as a de dicto claim might be something like “necessarily, Daniel is an animal.” Now it might not strike us immediately that de re and de dicto phrases are in any way different from one another, but consider something like this: “necessarily, a bachelor is an unmarried male” and “a bachelor is necessarily an unmarried male.” It seems clear that the de dicto expression is true, as it is positing a necessity between synonymous. The latter is clearly false, because many bachelors are not necessarily unmarried males, and many cease to be unmarried at some point in the future. Quine is suspicious of de re modality because of issues found in the above examples, but he makes his concern more explicit in the following:
- 9 = the number of planets.
- 9 is necessarily greater than 7.
From (10) and (11) can we infer that the number of planets is necessarily greater than 7? It seems not, because the number of planets can change, and not just by scientific fiat (poor Pluto). A few planets could blow up, or fall out of orbit around the sun. There seems to be no logical or metaphysical necessity that the number of planets in our solar system is greater than 7. So Quine reasons that de re modality is referentially opaque. If this is so, then Divine Propositions expressed in contemporary logic, where modality is treated as an operator, may also be referentially opaque. Let’s stipulate that Divine Propositions are identity statements about God, the Persons of the Trinity, or the Divine attributes. So, I argue that they are not merely identity claims, but de re identity claims. Now some philosophers claim that de re necessity is not referentially opaque. David Wiggins, for instance, endorses the following argument, claiming that opacity is a problem that “no longer presses”:
- Hesperus is necessarily identical to Hesperus.
- Hesperus is identical to Phosphorus.
- Hesperus is necessarily identical to Phosphorus.
I remain completely unconvinced that this argument is valid. While it might be the case that the object to which Hesperus and Phosphorus refer, the planet Venus, is necessarily self-identical, it doesn’t seem to me that there is any logical or metaphysical necessity that Hesperus and Phosphorus could not have been two distinct objects. So even though these are co-referring terms, it seems to me that de re identity is an intensional context, i.e. it is referring to the intension of the terms and relating them to one another by a necessity of identity. I find this tantamount to the following:
- I necessarily believe Hesperus is Hesperus.
- I believe Hesperus is Phosphorus.
- I necessarily believe Hesperus is Phosphorus.
Let’s say that (16) is true, that I am a consistent thinker. It seems odd though, that (17) should follow. Of course, those who think that de re contexts are not opaque will remain unconvinced. To me, this is one of the major shortcomings of contemporary modal logic, and is a primary motivator for seeking out a modal logic that avoids the opacity problem. In my estimation, Aristotelian modality has the advantage of making de re-like modal claims, but without being opaque. Aristotle achieves this by treating modality as a copula modifier rather than a predicate modifier, or movable operator. But this is a tangent that I will have to explore in later posts. Now let us re-examine Divine Propositions:
- God is necessarily identical to the Triune God.
- The Son of God is necessarily identical to God.
These are de re identity claims, and if these claims are referentially opaque, it unclear whether we can now infer from (18) and (19) the the Son of God is necessarily identical to the Triune God. So, if all identity relations said of God are de re identity claims, then substitution of identity cannot occur. This does not mean that certain substitutions will not happen to preserve truth, but that we simply cannot assume to make such substitutions. That is, the identity relation in Divine Propositions will not guarantee the preservation of truth when terms are substituted. This gives some philosophical reason to appeal to a certain mystery regarding God’s nature. That is, God’s nature cannot be fully comprehended, at least in part, because Divine Propositions are referentially opaque de re identity claims. Now one might object that if it is true that God is necessarily identical to the Triune God, then God is identical to the Triune God, and so we can reduce out the referential opacity so that the substitution problem arises. One response to this would be to say that it is simply false to assume that the reduction from de re modality is truth preserving for Divine Propositions. For if we assume that Divine Propositions are, at the very least, always based on identity, then a certain problem arises with Divine Identity itself. That is:
- God’s identity to the Triune God is identical to God’s necessary identity to the Triune God.
If God’s identity to the Triune God is identical to necessary identity, then we must ask whether the identity relation that relates the two sorts of “God’s identities” is itself referentially opaque. If we grant that “identity” is not referentially opaque in (20), then by transitivity “God’s identity” on the left side is referentially opaque as it is on the right side. Alternatively, we might deny that such a transitive relation exists in (20), but that must be because it is an opaque context despite being explicitly de re. And this is precisely what we are arguing. So the conclusion seems unavoidable. Another objection one might make is that referential opacity disappears if the same intensional context is used throughout an argument. So, for instance:
- I believe that the Boston Strangler = Bobby Orr.
- I believe the Boston Strangler = Albert DeSalvo.
From this, it seems that I can validly infer that:
- I believe that Bobby Orr = Albert DeSalvo.
Is this true? Well, not if I am an inconsistent believer. We have to make certain doxastic assumptions about me, in addition to these premises, to reach that conclusion. What about in the case of de re modality?
- 9 is necessarily identical to the number of planets.
- 9 is necessarily greater than 7.
Does the following follow?
- The number of planets is necessarily greater than 7.
Can we make this inference? I suspect not without making certain assumptions about the kinds of necessity at play. Even then, it is ambiguous as to which sort of “necessity” is found in the conclusion. So, I don’t think including the same opaque context throughout an argument transforms the premises into something transparent. For instance, it may be that (24) is about metaphysical necessity, nomological necessity, physical necessity, or some other sort of necessity? Is the same sort of de re necessity used in (25)? I think most of us would see (25) as some sort of logical, or arithmetic necessity. What about in the case of Divine de re claims? Well, we would have to have a clear sense of the univocal way in which God’s attributes and persons are related to one another by de re identity. I suspect that our own understanding of the ways in which these relations are described will vary from logical necessity, to metaphysical necessity, to necessities that are contextualized by our understandings of specific attributes. For instance, there is a sense in which the Father is unbegotten and necessarily exists a se, and a sense in which the Son is begotten, but still necessarily existing in that the divine relation from the Father to the Son is a necessary because of the metaphysics of subsistent relations, or because of some necessity in the nature of perfect love and community. So the Son is necessary, but begotten of the Father, which doesn’t seem to be exactly the same sort of necessity. Is there an overarching sense in which the Father and Son are both necessary, sure, but that sense may be beyond our immediate comprehension. Consequently, I find it dubious that we can settle on one opaque de re context in all of our discussions of God. And even if we could, it is not likely that opacity can be remedied by maintaining the same context throughout an argument. Therefore, I think we must conclude that Divine Propositions, i.e. propositions about God, the Persons of the Trinity, and Divine Attributes that are linked together by de re identity relations can be strict, opaque, and not admit of transitivity. Thus, God’s nature can be described through the Divine Propositions, but God’s nature prevents inferences about specifics about His nature unsubstantiated by revelation, which preserves mystery. This is not a fallacious appeal to mystery though, but one that has philosophical motivation. If this is so, it represents one way that orthodoxy can be intellectually defended.
 See W.V.O. Quine. 1966. “Three Grades of Modal Involvement” in The Way of Paradox and other Essays. New York: Random House. pg. 161.
 See David Wiggins. 2001. Sameness and Substance Renewed. New York: Cambridge University Press. pp. 114-115.