1. I don’t regard Wikipedia as the gold standard of theological discourse.
Nor do I, but it is popular and common.
2. ”Consubstantial” simply means “of one and the same substance or essence” (OED).
Yes, but in the context of the Arian dispute, it carries an additional connotation, since neither side considered multiple divine essences.
3. At a minimum, the purpose of the homoousios clause was to exclude the notion that the Son is merely of “like essence” with the Father, rather than identical essence.
True, that's the core.
4. From what I’ve read, there’s a scholarly dispute over the more specialized question of whether homoousios was also meant to denote generic identity or numeric identity.
You appealed to Calvin. Here's what he had to say on the subject:
While he proclaims his unity, he distinctly sets it before us as existing in three persons. These we must hold, unless the bare and empty name of Deity merely is to flutter in our brain without any genuine knowledge. Moreover, lest any one should dream of a threefold God, or think that the simple essence is divided by the three Persons, we must here seek a brief and easy definition which may effectually guard us from error. But as some strongly inveigh against the term Person as being merely of human inventions let us first consider how far they have any ground for doing so. (Instant Toots I 13.2)
So while Calvin may have done some groundwork for your views, he didn't go that far. He didn't leave the orthodox fold. Your views seem closer to Adam Clarke than John Calvin.
5. You confuse the semantic question of what the word or concept means with philosophical question of how the Trinitarian persons can be consubstantial. That’s not a semantic question. Rather, that’s a question for philosophical theology. A Christian can affirm the consubstantiality of the Trinitarian persons without having to endorse any particular explanation.
6. I don’t have to explain how the Trinitarian persons are consubstantial to affirm their consubstantiality. I certainly don’t require a philosophical explanation or justification for my affirmation. Rather, it’s sufficient for me to affirm their consubstantiality in case I have exegetical warrant for the full divinity of the Father, Son, and Spirit.
There is a difference between what consubstantial means with how it can be. No one has any idea as to how the Trinitarian persons can be consubstantial, but that doesn't mean we don't know if consubstantial means numeric or generic identity.
7. Sexual metaphors like “generation” as well as kinematic metaphors like “procession,” don’t begin to explain the way in which the persons of the Godhead are consubstantial.
i) For one thing, a metaphor is, by definition, figurative rather than literal.
ii) For another thing, a metaphor posits an analogy between one thing and another.
iii) Apropos (i-ii), you need to delimit the intended scope of the metaphor to isolate and identify the literal comparison.
8. How do you decipher these metaphors? Do you think they stand for a source of origin and/or mode of origin? Do you think the Father caused the Son and the Spirit to be?
Through generation essence is passed from one to anther. In the Trinity, generation provides for the mode of continuation of existence. Not origination, for the Son is unoriginated. Not caused, for cause implies temporalityand this generation is eternal. But in a logical and ontological order, the Son proceeds from the Father.
If so, then that reduces the Son and the Spirit to the level of a creature. It also suggests some form of pantheism, like Neoplatonic emanationism.
This does not follow from eternal generation.
Or else it treats the Son and the Spirit as contingent beings whom the Father wills into being. That’s a self-defeating way to affirm the full divinity of the Son and the Spirit.
The generation may be seen as natural and necessary rather than volitional.
9. If your objective is to preserve numerical identity of the Father and Son, then “generation” undermines your objective since what is begotten shares the same specific nature as the begetter, but not the same numerical nature. Both the begetter and the begotten are property-instances of a generic quality. They concretely exemplify an abstract exemplar, which stands over and above them.
If you’re going to make an exception in the case of the Trinity, then that betrays the inherent limitations of the metaphor. And you need to show why your exception isn’t an ad hoc restriction on the controlling metaphor.
You undersell natural generation and oversell eternal generation to make space for this problem. In natural generation, while the whole nature isn't transferred, a part is. And that part is numerically one with the generator. So the metaphor of passing nature or essence does preserve the unity of the Trinity. Indeed without it, I doubt monotheism can be defended. Three distinct divine essences that are of them divine, is tri-theism.
Now it's true that the metaphor is restricted. Natural generation is in time, not eternal and only part of the nature is transferred, not the whole. And this is because we know God is one and eternal. Are these restrictions add hoc? Why can't we include what we know about the recipients of an analogy in understanding the analogy. Is it add hoc for me to think that if someone calls me chicken that they mean I am scared rather than that I have feathers and a beak?
10. The Bible doesn’t explain how the Trinitarian persons are consubstantial. And I doubt we could even grasp the explanation.
11. The best that philosophical theology can do is to offer analogies. And that can be useful as far as it goes. But even in that respect, we can come up with better analogies than generation and procession to illustrate the consubstantiality of the Trinitarian persons. As I’ve said in the past, I think the principle of symmetry is a better analogy.
At some point all analogies break down and crack and become messy like the egg analogy. But I like the rays of the sun or a river flowing from a lake. What's your preference, three dancers in unison?
12. Your effort to contrast two things that share an essence which is numerically one and simple over against two things with identical properties is decidedly unclear. For if two things share identical properties, then they are really one thing rather than two, according to Leibniz’ law (i.e. the identity of indiscernibles).
So if you have two identical glasses of water in each hand, what happens if you drink one? Did you really drink them both?
On the other hand, if Leibniz is really saying that logically two things can't be identical, and you accept his principle, that rules out your own understanding of consubtantiallity.
13. I don’t think the Trinitarian persons have the same essence “of themselves,” as if each person is the “source” of his own essence (if that’s what you mean), for sourcehood is inapplicable to a divine mode of subsistence.
But you deny they have their essence from another (either eternally or via origination), no? So in one sense they are of themselves or auto-theos, no?
14. Since you seem to think Eph 1:3 is in tension with my position, it’s up to you to spell out why you deem that to be so.
How can the Father be Christ's God, if He does not receive His essence from the Father. How can He be His Son, without eternal generation?