I have edited down the long OP to four of the more obvious arguments. I have numbered them, strangely enough, One through Four.
Do trinitarians have any answers to these specific questions?
The response that 'we know the Trinity is a clear scriptural truth, but wrapped in mystery so unfathomable that we can’t…fathom it" seems to me to be arguing backwards. If it was clear, there would have been a whole lot less meanness in church history, on both sides of the issue. If it isn’t clear, then it’s only natural to try to clear it up. If we can’t clear it up, then the jump to ‘well it is too ginormous for us to comprehend’ may be the only answer, but only if it is shown to be true.
There are acres and acres of smart trinitarians; I’ve read a few but still cannot get past things like 1-4.
I know that this has all been hashed and re-hashed for centuries, but it is evergreen in mankind’s attempt to understand God.
I’d prefer to have comments on this by referring to the aforementioned complicated numbering system.
**One **
BV: If there are two streams of consciousness, one human, the other divine, then presumably there are two (synchronic and diachronic) unities of consciousness. But it is not clear how one person can encompass two distinct unities of consciousness. The Chalcedonian definition requires that there be exactly one person with two natures. Now if there is exactly one person, then it seems there would have to be exactly one (synchronic and diachronic) unity of
consciousness. Otherwise, there would be something like multiple personality disorder.
TWO
The Son assumes humanity, that is acquires the property of being human by becoming humanly embodied. The Son also assumes a human rational soul and human body. ‘Soul’ is ambiguous here. Perhaps one can say that it means principle of life. But then perhaps this phrase turns out to be ambiguous too. In the Platonic sense, a soul is an immaterial mental substance. In the Aristotelian sense, a soul is a substantial form or property in virtue of which a living substance is alive. In the Platonic sense, the Son assumes a human rational soul by becoming a human rational soul.
BV: How exactly? By becoming identical to a human rational soul? How then could the Son retain its divine properties?
In the Aristotelian sense, the Son assumes a human rational soul by acquiring a property in virtue of which he is a human rational living substance. This could involve acquiring a distinctively human rational stream of consciousness. More straightforwardly, the Son assumes a human body by coming to stand in the relation of human embodiment to a human biological organism. I am taking ‘human body’ as human biological organism.
This is my substance dualist account of the Incarnation. But another account that equally defends the doctrine from the charge of inconsistency is the one Trenton Merricks provides in his paper ‘The Word became Flesh: Dualism, Physicalism, and the Incarnation’ (unpublished), where to be human is to be a human biological organism, in which case God becomes human by becoming a human biological organism.
BV: Both on your and Merrick’s accounts, I am left with my question of how one thing can have incompatible properties.
THREE
I do not believe that, in the Incarnation, one person incarnates himself in another person. The Son becomes incarnate or humanly embodied in a human biological organism. But this human biological organism is not a mental subject. So the Son does not incarnate himself in another person.
BV: The trouble with saying this is that the Son does not become man by assuming a human body, but by assuming a human body together with its animating rational soul, which latter is a mental subject. That a divine mind should acquire a human body is not so problematic; but that a divine mind should acquire a human mind-body complex is quite problematic. How can two minds/persons be one mind/person?
FOUR
BV: Here is the problem in a nutshell. Two persons in two natures gives you the heresy of Nestorius. But one person in two natures presents the problem of how one person can have radically different natures. If Christ is both fully divine and fully human, then Christ does not merely have a live human body, he also has a human mind. But how can there be two minds without two persons? If you say that a divine mind occupies a human body, then that is the heresy of Apollinaris.