Ed, this will be a rather truncated response to these points because I will address just the arguments you present here. A fair treatment of your arguments would need to address your article on these topics in American Catholic Philosophical Quarterly. However, two physical realities—time and space—limit me here.
The question I posed was why we should think that a presumptively fundamental physical reality (quarks and leptons, quantum fields, superstrings, or whatever) needs supernatural support in order to exist. Why isn’t the doctrine of continuous creation merely gratuitous? You reply:
“Now, this [my question] assumes that physical theory gives us an exhaustive description of electrons, quarks, and material reality in general, or at least something near enough to an exhaustive description for present purposes. For only if we make that assumption would the absence from physical theory of a reference to the need for a conserving cause give us any reason to think a material thing doesn’t require one. (Compare: The absence of legs from the Mona Lisa would give us reason to believe that the woman it pictures was legless only if we supposed that the portrait captures everything about her that there was to capture — which, of course, is not the case.)”
The Mona Lisa example is funny but misses the target. We know that women generally have legs, so viewing the Mona Lisa would never tempt us to believe that the woman in the picture had no legs. However, one of the salient issues between your view and mine is precisely whether we have any access at all to the nature of physical reality apart from the natural sciences. In my view physics gives us our only access to the nature of fundamental physical reality. If the “pictures” given by physics are the only representations we have, then, unlike Mona, we have no independent and reliable source of information about the properties of electrons. In that case, all we have to go on are the “pictures” of physics. By analogy, if I were to show you a picture of only one portion of one of those truly weird, unique creatures from the Cambrian-era Burgess Shale you would have no basis for judging whether the remaining portion had legs or not or, if so, how many. We can form no expectations at all on the basis of what we don’t know. Any attempt to do so would be a textbook instance of the argumentum ad ignorantiam.
A more fundamental point is that when I suggest that the notion of continuous creation is gratuitous, the argument is epistemic, not ontological. I take it for granted that it is not within the purview of physics to demonstrate metaphysical truth, e.g. about putative divine activities or the absence thereof. Rather, my point was that, since physical theory does not—cannot—indicate the need for the supernatural underwriting of the natural, why posit it? Why is such a supposition not episemically gratuitous? There may indeed be more things in heaven and earth than are dreamt of in our physics, but, without some adequate grounds for positing such things, it is those putative non-physical realities that remain dreams.
You argue however, that physics, in principle, cannot tell us the fundamental nature of things. You quote Bertrand Russell to the effect that fundamental physics can only reveal the “logical structure of events” while leaving us ignorant of the nature of the things that are changing. You continue:
“Now if physics gives us only the mathematical structure of material reality, then not only does it not tell us everything there is to know about material reality, but it implies that there must be more to material reality than what it tells us. For there can be no such thing as structure by itself; there must be something which has the structure.”
Russell interpreted quantum mechanics as implying an ontology of events, not things. I think he failed to realize that when we are talking about ex hypothesi fundamental things like elementary particles, the commonsense distinction between things and what they do is blurred. What could an elementary particle be except a bundle of definitive and irreducible properties in virtue of which it has its characteristic powers and liabilities? Elementary particles have no parts, constituents, or internal structure, and such basic kinds have no identity apart from their defining properties. In other words, I think that to say that, e.g. an electron is something WITH a given mass, charge, and spin is less accurate than to say that it is something that IS a given mass, charge, and spin.
We define an electron as:
“One of the elementary particles…with a rest mass of 9.1093897 × 10 -31 Kg, an electric charge of -1.60218925 × 10-19 coulombs and a spin of ½ , which obeys Fermi-Dirac statistics (John Gribbin, Q is for Quantum, Free Press, 1998).”
And this is the exhaustive description of the natural kind “electron.” Therefore, Russell’s claim assumes a distinction between thing and what it does that is not clear when we are talking about ex hypothesi fundamental things, which just are the basic properties in virtue of which they interact the way that they do.
“So, physics is of its very nature incomplete. It requires interpretation within a larger metaphysical framework, and absolutely every appeal to “what physics tells us” presupposes such a metaphysical framework, implicitly if not explicitly. This is as true of the appeals made by naturalists and atheists as it is true of the views of Scholastics.”
What metaphysical assumptions does physics make other than the ones necessary to do physics? Physics assumes the existence of an objective, external world that exhibits sufficient stability, regularity, and simplicity to be knowable. What else? Physics makes such minimal heuristic assumptions, and its very success justifies those assumptions. Does physics require—though physicists clearly seem oblivious to the purported fact—concepts like “prime matter” or “substantial form?” All I can say here is that I—and I imagine the vast majority of physicists—would find such a claim implausible in the extreme, and we would place a very heavy burden of proof on anyone claiming that physics does require such concepts. (Ed: when I—someday—get the time to review in detail your admirable book Scholastic Metaphysics I hope to say a great deal more).
To sum up (BTW, I am unabashedly fudging by not counting quoted material towards my 1000 word limit): Even if physics is incomplete, this does not show that physical reality is. Even if physics does not, or cannot, tell us the true nature of things, this conclusion does not establish that physical things need supernatural help to exist. To argue from the (alleged) incompetence of physics to discover the whole of reality to the probable or even plausible existence of non-physical realities (like continuous creation) is a clear argumentum ad ignorantiam. Such a claim rises and falls completely with the details of Scholastic metaphysics and is indeed gratuitous outside of that context.