The doctrine of the Trinity does not say there is one God and three Gods, or that God is one Person and three Persons, or that God has one nature and three natures. Those would indeed be self-contradictory ideas. But the doctrine of the Trinity says that there is only one God and only one divine nature but that this one God exists in three Persons. That is a great mystery, but it is not a logical self-contradiction.
Peter Kreeft, Fundamentals of the Faith, (Ignatius, 1988), p.42.I don't think that the doctrine as so stated (above) rises to a level of clarity that allows for Kreeft's last sentence. Do you?
I agree with you, Dave.
First sentence: Exactly right.
Second sentence: Right again.
Third sentence: Also correct.
Fourth sentence: this is a bare assertion sired by confusion. The confusion is between the explicitly or manifestly contradictory and the implicitly or latently contradictory. The following are all explicitly self-contradictory:
a. There is only one God and there are three Gods.
b. God is one person and God is three persons.
c. God has one nature and God has three natures.
To be precise, the above are self-contradictory in the logical presence of the proposition that nothing can be both numerically one and numerically three. To be totally precise, then, I should say that the above three are near-explicitly self-contradictory to distinguish then from, say, 'God is one person and it is not the case that God is one person,' which is an explicitly formal-logical contradiction, i.e., a contradiction whose contradictoriness is rooted in logical form alone: *p & ~p.* Such contradictions I call narrowly-logical to distinguish them from (wait for it) broadly-logical contradictions such as *Some colors are sounds.* But
d. There is exactly one God in three divine persons, the Father, the Son, and the Holy Spirit
though not explicitly or near-explicitly contradictory as are the above three examples, is nonetheless contradictory in that it entails (in the logical presence of other orthodox doctrinal claims and self-evident truths) contradictions. How? Well, consider this aporetic septad:
1. There is only one God.
2. The Father is God.
3. The Son is God.
4. The Holy Spirit is God.
5. The Father is not the Son.
6. The Son is not the Holy Spirit.
7. The Father is not the Holy Spirit.
If we assume that in (2)-(7), the 'is' expresses absolute numerical identity, then it is clear that the septad is inconsistent. (Identity has the following properties: it is reflexive, symmetric, transitive, and governed by the Indiscernibility of Identicals). For example, from (2) and (3) taken together it follows that the Father is the Son by Transitivity of Identity. (That identity is a transitive relation is an example of a necessary and self-evident truth.) But this contradicts (5): The Father is not the Son.
So we have an inconsistent septad each limb of which is a commitment of orthodoxy.
What this shows is that (d) above, while not explicitly and manifestly contradictory as are (a)-(c), is nonetheless contradictory in that it entails three explicit formal-logical contradictions, one of them being *The Father is the Son and the Father is not the Son.*
Of course, there are various ways one might try to evade the inconsistency of the above septad. But this is not the present topic. The present topic is whether Kreeft's fourth sentence is justified. Clearly it is not. The mere fact that (d) is not obviously contradictory as are (a)-(c) does not show that it is not contradictory. I have just argued that it is.
Kreeft says in effect that (d) is a "great mystery." Why does he say that it is a mystery if not because it expresses a proposition that we find contradictory? If we didn't find (d) contradictory we would have no reason to call it mysterious. So Kreeft is in effect admitting that we cannot make coherent logical sense of (d). This suggests that Kreeft may be waffling between two views:
V1: The doctrine of the Trinity, though of course not rationally provable by us (because known by revelation alone) is yet rationally acceptable by us, i.e., free of logical contradiction, and can be see by our unaided reason to be free of logical contradiction
and
V2: The doctrine of the Trinity cannot be seen by us to be rationally acceptable in the present life, and so must remain a mystery to us here below, but is nonetheless both true and free of contradiction in itself.
(V1) and (V2) are clearly distinct, the latter being a form of mysterianism. I raised some doubts about Trinitarian mysterianism yesterday.
Thanks Bill.
(d)is almost a textbook definition of the 'heresy' of Modalism:
"...this view (modalism) states that the Father, the Son, and the Holy Spirit never all exist at the same time--only one after another. Modalism denies the distinctiveness of the three persons in the Trinity even though it retains the divinity of Christ." (https://carm.org/modalism)
The (pretty much -to me- incoherent) creedal formulae concerning the Trinity have spawned almost all of the so-called heresies in the Christian church.
Posted by: Dave Bagwill | Saturday, September 12, 2015 at 01:00 PM
Honestly, Dave, I don't see how you get modalism out of (d). It is the orthodox doctrine.
As Kreeft puts it, "But the doctrine of the Trinity says that there is only one God and only one divine nature but that this one God exists in three Persons." That is exactly the orthodox, non-heretical Catholic view.
What Kreeft fails to see is the logical contradiction hidden within the doctrinal formulation. He doesn't see it because it is not lying on the surface but has to be dug out.
Posted by: Bill Vallicella | Saturday, September 12, 2015 at 01:19 PM
I understand that Kreeft's statement is the Catholic view. My contention is that (d), not Kreeft's statement, is modalism.
(d) does not state that God "exists in" three Persons - I'm getting at the contemporaneous-ness (awkward, that) aspect of the statements. Modalists would also believe that God is in three persons - but consecutively.
Posted by: Dave Bagwill | Saturday, September 12, 2015 at 01:43 PM
It seems to me that (d) and Kreeft's statement say the same thing -- they are only slightly verbally different.
But let's not discuss this. Just substitute Kreeft's statement for (d).
Kreeft is a popular writer, so it may be churlish of us to hold him to high standards of rigor. And I don't have his book, so I can't check the context of his quotation.
Posted by: Bill Vallicella | Saturday, September 12, 2015 at 01:56 PM
I may not understand "numerical identity," but if (1) implies that there is numerically one God--as opposed to, say, seventeen--I think many big time Christian metaphysicians would deny this claim. On the Aristotelian program that is usually operative in the speculative work of these theologians, "number" is a species of quantity, which is an Aristotelian accident. There are no accidents in God, so any quantitative predicate (even being "numerically one") would not apply properly to God.
I don't know if this ends up dissolving your criticism, but it seems to me that there is quite a bit of disparity between this sort of analytic metaphysics and the radically different metaphysical vocabulary that someone like Aquinas (but not only Aquinas, by any means) is employing. Unum is an analogical predicate (a transcendental, co-extensive with ens), and when predicated of the divine essence it has nothing to do with being numerically one. I think we need this sort of conceptual flexibility if we are to say something about the mystery of the Trinity.
[Note: this is not to say I have anything approaching a good grasp on orthodox trinitarian doctrine]
Posted by: Josh | Saturday, September 12, 2015 at 02:59 PM
It seems that the following premises are false:
5. The Father is not the Son.
6. The Son is not the Holy Spirit.
7. The Father is not the Holy Spirit.
The more accurate rendering is: The Father does not have **the same nature as** the Son.
The Son does not have **the same nature as** the Holy Spirit.
The Father does not have **the same nature as** the Holy Spirit.
We have no contradiction here because Personhood is preserved.
Posted by: Robert Enright | Sunday, September 13, 2015 at 12:37 PM
That's not right. As Kreeft rightly points out in his third sentence quoted above, there is only one God, and only one nature, the divine nature. That one nature is shared by the Persons.
Posted by: Bill Vallicella | Sunday, September 13, 2015 at 01:38 PM
I stand corrected with regard to the **nature** of the Father and the Holy Spirit. They share only a divine nature. The Son shares the **divine** nature with the Father and the Holy Spirit, but they do not share the same nature as the Son in that the Son also has a **human** nature. So, there may be an equivocation with regard to the term Person. It could mean separate individuals, in which case there is a contradiction. It could mean different **functions,** in which case there is no contradiction.
Posted by: Robert Enright | Sunday, September 13, 2015 at 01:46 PM
Robert,
Right. The Son has both a divine nature and a human nature. But isn't it the case that before the historical event of the Incarnation, the Son had only a divine nature?
God is necessarily triune. But there was no necessity that the Son be incarnated. So, as I understand it, it is contingent that the Son has both a divine and a human nature.
But the Incarnation is a separate topic, and we can discuss the Trinity without making reference to the Incarnation.
Posted by: Bill Vallicella | Sunday, September 13, 2015 at 02:57 PM
Josh,
Your comment was sent to the spam corral where I just now found it. Perhaps I will find time to address it later.
But for now: numerical identity as opposed to qualitative identity. Surely you are aware of that distinction?
Posted by: Bill Vallicella | Monday, September 14, 2015 at 05:12 AM
Some have argued that God is essentially agape-love. God didn't need to create other beings in order to love. He is eternally and necessarily loving. But agape-love requires at least two persons. Thus, God is eternally and necessarily multi-personal.
If this line of reasoning is plausible, then we'd have a good reason for holding to trinitarianism despite the logical difficulties.
Posted by: Elliott | Tuesday, September 15, 2015 at 10:23 AM
Josh:
Without quoting chapter and verse, Aristotle especially and pre-Modern mathematics in general does not consider *one* a number. Or *two*: *three* is the first number as the first number that is for measuring. Think of having a ruler with no marks on it: you cannot 'count' i.e. measure any length shorter than it; any length longer, you might as well say you have a mental ruler made up of two or more of the original.
Instead of 'one' for Latin *unum* consider instead 'unit' as capturing it better. In this conception, nobody 'counts' one cow. (And a little harder for me to grasp, one doesn't count two cows so much as note there is another cow.
Chris Kirk
Posted by: Chris Kirk Speaks | Tuesday, September 15, 2015 at 06:42 PM
Regarding the aporetic septad: What if we assume that in (1) the 'is' expresses existence, in (2)-(4) the 'is' expresses constitution, and in (5)-(7), the 'is' expresses absolute identity?
If feasible, this account enables us to avoid the contradictions entailed by assuming that (2)-(7) use the 'is' of absolute identity. This account would also enable us to hold V1, although it would seem to rule out the doctrine of divine simplicity.
Posted by: Elliott | Wednesday, September 16, 2015 at 06:40 AM
So the F, S, and HS are proper parts of God? This has its own problems.
Posted by: Bill Vallicella | Wednesday, September 16, 2015 at 10:51 AM
Yes, that would be the idea.
One apparent problem is that if the DDS is correct, this part-whole account doesn't work. And there are reasons to accept the DDS.
Another apparent problem is that the part-whole account would make it difficult to explain the aseity of God, if we assume that a whole depends on its proper parts. But perhaps a whole doesn't always depend on its parts.
A third apparent problem is that omni-attributes such as omniscience and omni-benevolence would seem to be attributes of the persons as parts. But maybe that's not a problem.
Posted by: Elliott | Wednesday, September 16, 2015 at 12:01 PM
W.L. Craig seems to argue for such a view in A Formulation and Defense of the Doctrine of the Trinity.
For example, he writes "Now if a cat is feline in virtue of being an instance of the cat nature, in virtue of what is a cat’s DNA or skeleton feline? One plausible answer is that they are parts of a cat. This suggests that we could think of the persons of the Trinity as divine because they are parts of the Trinity, that is, parts of God. Now obviously, the persons are not parts of God in the sense in which a skeleton is part of a cat; but given that the Father, for example, is not the whole Godhead, it seems undeniable that there is some sort of part/whole relation obtaining between the persons of the Trinity and the entire Godhead."
He also writes "Suppose, then, that God is a soul which is endowed with three complete sets of rational cognitive faculties, each sufficient for personhood. Then God, though one soul, would not be one person but three, for God would have three centers of self-consciousness, intentionality, and volition, as Social Trinitarians maintain. God would clearly not be three discrete souls because the cognitive faculties in question are all faculties belonging to just one soul, one immaterial substance. God would therefore be one being which supports three persons, just as our individual beings each support one person. Such a model of Trinity Monotheism seems to give a clear sense to the classical formula “three persons in one substance.”
Read more: http://www.reasonablefaith.org/a-formulation-and-defense-of-the-doctrine-of-the-trinity#ixzz3lvkoNU8D
Posted by: Elliott | Wednesday, September 16, 2015 at 12:50 PM
I address the cat-skeleton analogy here: http://maverickphilosopher.typepad.com/maverick_philosopher/2013/01/is-the-skeleton-of-a-cat-feline-in-the-same-sense-a-feline-is.html
Posted by: Bill Vallicella | Wednesday, September 16, 2015 at 01:19 PM
Thanks for the thought-provoking link, Bill!
You wrote "Since a skeleton is called feline only by reference to an animal whose skeleton it is, I suggest 'feline' in application to a cat skeleton is being used analogically."
Are you assuming that there is only one way to be feline: by being a substance that has the feline nature?
Perhaps there are two ways to be feline: by exemplifying the feline nature and by being a proper part of something that exemplifies the feline nature. If this is correct, then maybe the feline skeleton isn't analogically feline.
Similarly, maybe there are two ways to be divine. Craig notes that God is divine and each of the Persons are divine, but that God is triune and the Persons as individuals are not triune, suggesting that the Persons are divine in a different way.
Consider another analogy: the human soul. Maybe there are two ways to be soul.
Suppose the soul has proper but inseparable parts, such as a rational part and a desiderative part. (I'm not arguing that the human soul has parts, but only supposing it does in order to make the point.) The soul itself is 'soul.' The parts are also 'soul.' The soul is rational. The desiderative part isn't rational, but is 'soul.'
Posted by: Elliott | Thursday, September 17, 2015 at 05:18 AM
@BV: Yes, I think I have a rough-and-ready grasp of numerical vs. qualitative identity. Does this site have it right? I ask because this is basically the way I understand it.
http://www.jimpryor.net/teaching/courses/intro/notes/numerical.html
@Chris Kirk, thanks for that clarification. That makes a lot of sense. Maybe my question can be made clearer if I just ask whether we can recognize a difference between substantial unity and numerical unity, since that seems to be operative in pre-modern approaches to the trinity.
Posted by: Josh | Monday, September 21, 2015 at 07:43 AM