I won't deny that there are watered down versions of the Thomistic soul that are agnostic with respect to the physicality or super-naturality of things like digestion, but Aquinas himself is quite clear:
> The lowest of the operations of the soul is that which is performed by a corporeal organ, and by virtue of a corporeal quality. Yet this transcends the operation of the corporeal nature; because the movements of bodies are caused by an extrinsic principle, while these operations are from an intrinsic principle; for this is common to all the operations of the soul; since every animate thing, in some way, moves itself. Such is the operation of the "vegetative soul"; for digestion, and what follows, is caused instrumentally by the action of heat, as the Philosopher says (De Anima ii, 4).
That is to say: we cannot explain things like digestion "naturally" as we would require an "external principle" that does not exist for living things, instead because they "move themselves" they require a super-natural explanation, i.e. the soul.
Indeed, Aquinas puts the following as a potential object, which he rebuts
> Objection 1: It would seem that the parts of the vegetative soul are not fittingly described—namely, the nutritive, augmentative, and generative. For these are called "natural" forces. But the powers of the soul are above the natural forces. Therefore we should not class the above forces as powers of the soul.
> On the contrary, The Philosopher says (De Anima ii, 2,4) that the operations of this soul are "generation, the use of food," and (cf. De Anima iii, 9) "growth."
The word 'soul' is used by Aquinas and Aristotle in a very different way from how modern people (from Descartes onward) use it, and this is the cause of an enormous amount of confusion.
Edward Feser's book Aquinas is a good starting point for understanding it.
I am quite familiar with Ed Feser, I refer to his writings often.
Indeed, Aquinas is using the soul the way that modern scientists use "dark matter". Except where the modern problem is unexpected rates of universal expansion, Aquinas' problem is vitalism-qua-"why are living things different than non-living things."
Once we abandoned vitalism, the conception of the soul must therefore also change. But in my reading of history, there is no clear break; no "before" and "after". Aquinas' definitions and concepts were never really abandoned, the church just retreated from the bailey of "the soul explains all the features of living matter including how it moves around" to the motte of "the soul explains intellect/reason/will since thats the only thing left thats not obviously physical."
Indeed, you will see that Aquinas' language suffuses most official Catholic teaching on the soul, even though the official teachings are usually a slightly generalized version of Aquinas's concrete assertions.
> you will see that Aquinas' language suffuses most official Catholic teaching on the soul
I wish I could find the document, but about 2 years ago, the Vatican released an official document explaining that Rome had been using certain philosophical traditions, including Thomism, in its official documents and councils for a few hundred years, because it was convenient, yet without making it official to any degree. I was so happy when it came out because it vindicated what I had been telling all my Thomist friends, that Thomism is not official Catholic doctrine.
Metaphysics is not some interchangeable bolt-on to theology, like the parts of a vacuum cleaner. If you change metaphysics, you change theology. Nominalism led directly to Protestantism, for example. Hume and Kant led directly to theological modernism (and heavily influenced personalism). Etc.
Maybe this is true for non-Catholic theology. But Catholic theology has no inherent need for metaphysics.
As St. John Henry Newman put it: "Christianity is eminently an objective religion. For the most part it tells us of persons and facts in simple words"
Metaphysics are not a required aspect of Catholic theology, because Catholic theology is neither systematic nor a philosophy, but just a set of objective, historical claims. They might have implications, but even those are unclear.
For example, with the story of the multiplying of the fish and the loaves, there is no definitive answer as to how this occurred. Only that over five thousand people were there, they had this many loaves, everyone ate their fill, and afterwards they had more loaves left over.
Metaphysics might be helpful in guessing how this happened, but it's neither required nor infallible when explaining it.
Did you see the magisterial quotes I linked to? Do you think they're wrong?
Examples of the importance of metaphysics to theology are innumerable. To take a few off the top of my head:
If you don't hold to a classical metaphysics, your understanding of transubstantiation will be different from the Church's. Locke, famously, mocked the idea of 'substance', so one can hardly believe in transubstantiation while holding to a Lockean metaphysics.
If you are a metaphysical idealist after the manner of Berkeley, the quote from Newman you provided can't be right, because persons and facts would be mere artifacts of the mind.
With the multiplying of the fish and loaves, we only know that this is a miracle because we know that a miracle is something that occurs outside the normal course of nature; but we only know that there is a normal course of nature because of a particular metaphysics. (If we adopt Hume's metaphysics, for example, then there is no normal course of nature, and so everything is a miracle, and so there should be nothing unusual or surprising about the multiplication of the fish and loaves.)
As we've seen, what you understand by the word 'soul' is profoundly affected by metaphysics.
And so on and so on. Metaphysics affects everything. People who say we don't need it, whether they're discussing natural science, theology, ethics, politics, or whatever else, end up contradicting themselves without fail. History is replete with examples.
> Did you see the magisterial quotes I linked to? Do you think they're wrong?
The very recent official Vatican document I referred to elsewhere here explained that, while the Church has utilized Aristotelian explanations of Catholic theology, especially as used by St. Thomas Aquinas, even in official Church documents such as the Council of Trent, this in no way officialized this theology, but was only used as a convenience.
> If you don't hold to a classical metaphysics, your understanding of transubstantiation will be different from the Church's. (The word only makes sense in an Aristotelian context.)
Right, the Catholic Church says that if you use St. Thomas Aquinas's explanations of Catholic theology through the framework of Aristotle, then yes, his explanations are correct. However, it also says you do not need to use his framework, and in fact new ways of explaining Catholic theology should be sought out, in much the same way the Early Church Fathers did.
> And so on and so on. Metaphysics affects everything.
> because persons and facts would be mere artifacts of the mind.
These two things you said are clearly showing me that you're not understanding me.
You're thinking of everything I'm saying through the eyes of some metaphysics. You're presuming it.
I'm not. I'm looking at reality in a common, everyday way, experientially, in the same way practically every person does all the time in their daily lives.
The difference is depth.
When we examine any aspect of reality, you seem to take it as far down as you concretely can. (I wonder if it's all just turtles for you.) You go depth first.
Whereas I myself go breadth first, and only as deep as needed to resolve a given question.
So when we talk about the multiplying of the loaves, you've already brought metaphysics in. You've presumed some kind of framework.
Whereas when I think about it, there is a point A and a point B. The point A is the historical facts as laid out by the gospel authors. The point B is some question, such as "how did they end up with more bread?" or "where did the new bread come from?"
For me, I don't need to go beyond answering the concrete questions. I draw in whatever external questions and answers are needed to answer the question I'm faced with. That may result in me pulling in a framework.
For St. Thomas Aquinas, it did. He pulled in Aristotle, patched it up, married it to Catholic theology, and used that.
I don't have to. I go through this process much more shallowly. The best analogy is that I use lazy evaluation of such questions, and you seem to think with fully eager evaluation. Almost as if it were an inherent necessity.
You may be familiar with it, but you haven't understood it. 'Soul', for Aristotelian-Thomist philosophy, simply means the form of a living thing. A form of anything is what makes it what it is. The form of quartz is what makes this particular chunk of matter be quartz. The form of an oak tree is what makes that particular chunk of matter be an oak tree. The same is true for a dog, or a man. But in the latter three cases we call the form a 'soul'.
So yes, of course the form of a living thing is what makes it be different from a non-living thing! That in no way implies vitalism, if by that you mean a mysterious force that makes a dead but otherwise complete animal body come alive. The form (soul) of a body is what makes this particular body -- and body is understood in the classical sense of "solid lump of matter", not in the modern sense where it refers only to an animal -- be what it is. Just as it would be for any other material thing in reality.
And to head off the charge of obscurantism, and deal with your "god of the gaps" assertion, this not meant to be a complete, biological explanation. Nor is it meant to be some explanation for something that we can't otherwise understand by scientific means. It is only the beginning of an explanation of why a thing is what it is. It falls to the particular science, in this case biology, to flesh out (pun not intended) the details.
Hylemorphism (the form-matter distinction) is an absolutely basic Aristotelian doctrine, and without understanding it, complete confusion will result from trying to understand Aquinas' (or Aristotle's) discussion about the soul. Of course, you may think hylemorphism is nonsense, but that's a different argument.
You also refer to the soul as a "supernatural" principle in a previous post. Again, this way of talking and thinking is utterly foreign to Aquinas. He does not think digestion requires a supernatural explanation. This shows a very grave misunderstanding.
First, the 'On the contrary...' in the article is not a rebuttal to the specific objection but a quote from an authority (Aristotle) supporting his general position. His specific rebuttal distinguishing the senses of 'natural' is later in that article.
Second, the soul is not, on the Aristotelian-Thomistic thesis, a "supernatural" being, as an angel or God would be since (though not material themselves) they properly belong to the material order.
So these are natural, not supernatural explanations, which nevertheless go beyond the purely material (corporeal) and so are 'above' them. In the quoted article, he means that these characteristic activites of living things are not simply reducible to those of the material parts themselves, since the living thing possesses the principle of its own organization/growth/reproduction etc. that non-living material does not, so something beyond the non-living 'corporeal' order must be operating.
Aquinas is explaining the formal cause i.e, the soul. The physical particulars of how digestion work would be the agent and material causes. He wouldn't deny that they exist. Modern science erroneously disregards formal and final causality.
And yet vegetative life stops digesting when the plant dies. The mechanics are all still there, but we can not make them continue. To take an example dear to HN, we can't make the old American Chestnut trees "start" again once they have died.
Thomism is very overrated, people seem to lean on it because it sounds smart, and maybe it was for its time, but it relies entirely on Aristotelianism, and such systematic metaphysical philosophies are only as good as the physics they base themselves on, and Aristotle's physics were garbage (not entirely his fault).
> The lowest of the operations of the soul is that which is performed by a corporeal organ, and by virtue of a corporeal quality. Yet this transcends the operation of the corporeal nature; because the movements of bodies are caused by an extrinsic principle, while these operations are from an intrinsic principle; for this is common to all the operations of the soul; since every animate thing, in some way, moves itself. Such is the operation of the "vegetative soul"; for digestion, and what follows, is caused instrumentally by the action of heat, as the Philosopher says (De Anima ii, 4).
That is to say: we cannot explain things like digestion "naturally" as we would require an "external principle" that does not exist for living things, instead because they "move themselves" they require a super-natural explanation, i.e. the soul.
Indeed, Aquinas puts the following as a potential object, which he rebuts
> Objection 1: It would seem that the parts of the vegetative soul are not fittingly described—namely, the nutritive, augmentative, and generative. For these are called "natural" forces. But the powers of the soul are above the natural forces. Therefore we should not class the above forces as powers of the soul.
> On the contrary, The Philosopher says (De Anima ii, 2,4) that the operations of this soul are "generation, the use of food," and (cf. De Anima iii, 9) "growth."