b. Agere sequitur esse: whatever operates I-ly must be (exist) I-ly.
c. The human soul, qua executing immaterial operations, exists immaterially.
Remember, that is the issue that I have been addressing. It seems to me that Bill keeps shifting the focus of his arguments between two claims -- the claim that hylemorphic dualism is true, and the claim that hylemorphic dualism can have a purely philosophical, non-apologetic rationale -- and writes as if his objections to the first claim somehow establish the falsity of the second. But they don’t. Thus, even if Bill has presented powerful objections to the first claim (though I don’t think he has) that would be irrelevant to the second claim, which is the one at issue.
Hence when Bill concludes his post by saying:
[Ed] has not given me a reason why I should accept argument A below over argument B:
Argument A: The human soul can exist apart from its body; the human soul is the form of the human body; therefore, there are forms that can exist apart from the matter they inform.
Argument B: The human soul can exist apart from its body; no form can exist apart from the matter it informs; therefore, the human soul is not the form of the human body.
the trouble is that I have not been trying to convince Bill to accept argument A over argument B. Rather, I have been trying to convince him that argument A, no less than argument B, is an argument someone could adopt on purely philosophical grounds, and not merely on Christian apologetic grounds. And I think I have shown that that much is true. (For those who are interested, you can find my most detailed discussion and defense of hylemorphic dualism in chapter 4 of Aquinas.)
I want to end this post by emphasizing how much I value Bill’s criticisms. I think that the most formidable general metaphysical systems fall into three categories: the broadly Aristotelian approach, especially as developed by Scholastics like Thomists, Scotists, and Suarezians; the broadly Platonic approach, especially as developed within the Neo-Platonic tradition; and the broad rationalist-idealist approach represented by moderns like Leibniz, Bradley, Whitehead, and many others. Needless to say, my sympathies are with the first camp. Bill, at least as I read him, tends to sympathize more with lines of argument representative of the latter two camps (which is not to say that he is “a Platonist” or “a rationalist” or “an idealist,” full stop). The three traditions are united in their opposition to the naturalism that dominates contemporary philosophy, which dominance is (as I see it) historically aberrant and temporary, since naturalism is the least plausible of the alternatives. (Most naturalists think otherwise, of course. But as it happens, most naturalists also seem to know little of the other three traditions in question except the crudest caricatures, as is obvious to any Aristotelian, Platonist, rationalist, or idealist who reads what naturalists have to say about these systems.)
Given the shallow and historically ill-informed character of so much (not all, but much) contemporary naturalist argument, each of these three anti-naturalist systems has to look mainly to the other two rival systems for serious objections. It is in that spirit -- and because of his erudition and philosophical acumen -- that I always value Bill’s criticisms. (Incidentally, Bill’s very helpful remarks on my ACPQ paper “Existential Inertia and the Five Ways” saved me from a foolish mistake that I had made in the original draft.)