In the process, one commenter, Matt, wrote to clarify the type of logical fallacy that Newman's theory rested upon.
Dr. Witt has kindly responded via email, and his response is reproduced here.
Dear John Bugay,
Thanks for linking to my post on the incoherence of Newman's account of development. Readers might find it helpful to know that this is part of a lengthy discussion I have been having with Roman Catholic disciples of Newman, and one in particular.
Thank also for pointing out that "fallacy of amphiboly" is not correct, and that I was careless in the spelling. I plead that the quoted portion here is from a transcript of a letter I had written rather quickly. I did not bother to check whether or not the fallacy was named correctly, since I was giving practical advice, not writing for publication.
Amphiboly is an amibiguity of language, not terms. So, Groucho Marx's "I shot an elephant in my pajamas. What was he doing in my pajamas, you ask?"
At the same time, I am not quite happy with "equivocation." Terms like "river bank" and "First Savings Bank" are equivocal, as are the "bark of a tree" and the "bark of a dog." The fallacy here seems to deal with terms that have almost the same meaning, but are different enough as to not be univocal. Both Development 1 and Development 2 are developments, but they differ in a way that invalidates Newman's argument. If someone knows of another fallacy besides equivocation that covers this category, I would be grateful. Meanwhile, I have corrected my blog.
You might find it amusing that my primary interlocutors in this discussion have been Roman Catholic philosophers (not theologians), some of whom I find referenced on your blog, none of whom picked up on careless fallacy identification. The response has rather been to embrace Development 2 wholeheartedly--to insist that both homoousious and papal infallibility are equally developments for which only the authority of the magisterium can suffice. That is, if it had not been for Nicea, the Arian view would be equally plausible as orthodoxy.
While conceding the force of my argument, I find this a desparate concession. It necessarily would imply that the doctrine of the incarnation is just as lacking in biblical or theological warrant as are the marian dogmas or papal infallibility.
I hope I was clear about what I meant when I wrote: "She gives birth, however, to Jesus’ humanity, not his eternal person, which has always existed and is generated eternally by the Father." I addressing the fairly obvious objection that inevitably arises to the claim that Mary is the Mother of God: God is eternal; Mary is not eternal. If Mary is the Mother of God, then God came to exist in time, and Mary's existence predates God. But Mary is not eternal, ergo . . .
I would say that mothers give birth neither to persons nor to natures, but to human beings. A human being is a single substance in which one can distinguish between person and nature. The person is the subject of the predicate "who," while nature is the subject of the predicate "what." Both persons and natures are created by God.
The orthodox doctrine is that the incarnate Word is a single divine person with two natures, one human, one divine. The doctrine of anhypostasia means that Christ has no human person; the doctrine of enhypostasia means that Christ is a single divine person who is the subject of unity in the incarnation. The doctrine of communicatio idiomatum means that properties of either nature can be predicated of the single divine person, which can result in some paradoxical statements: "My God died" is true, although God is eternal and cannot die, because the incarnate Word of God (the second person of the Trinity) died in his human (not his divine) nature. Jesus' humanity comes to exist in time, both created by God, and the progeny of his mother Mary. His divine person, however, is eternally begotten of his Father, and never comes into existence.
In stating that Mary is the theotokos or Mother of God, there is an ambiguity. Mary gives birth to Jesus. Who is Jesus? Jesus is God. Mary is then the Mother of God. What is Jesus? Jesus is completely human and completely divine. Is Mary the "bearer" or Mother of Jesus' humanity? Absolutely. Although created by God, everything of Jesus that is human (body, intellect, will, soul) are received from Mary his mother. Is Mary the "bearer" or Mother of Jesus' divinity? No. Insofar as it is eternal, Jesus' divinity (his divine nature) can have no "mother."
Is Mary bearer or the mother of Jesus' divine person? A tricky question. If by "mother," one means that Mary gives birth to Jesus who is a single divine/human identity, and whose person is fully God, then the answer is "yes."
If, however, by "mother," one means that Mary is the human source of Jesus' divine personhood in the same sense that she is the source of his humanity, or the same sense that other mothers are the source of their offspring's human personhood (although also created by God), the answer must be "no" because Jesus has no human person. His divine person is eternally generated by the Father and does not come to be in time. It is "begotten, not made."
Grace and Peace,
William G. Witt
Assistant Professor of Systematic Theology
Trinity School for Ministry