Thomas Aquinas, following Aristotle, views the soul as the form of the body. Anima forma corporis. Roughly, soul is to body as form is to matter. So to understand the soul-body relation, we must first understand the form-matter relation. Henry Veatch points out that "Matter and form are not beings so much as they are principles of being." (Henry B. Veatch, "To Gustav Bergmann: A Humble Petition and Advice" in M. S. Gram and E. D. Klemke, eds. The Ontological Turn: Studies in the Philosophy of Gustav Bergmann , University of Iowa Press, 1974, pp. 65-85, p. 80) 'Principles' in this scholastic usage are not propositions. They are ontological factors (as I would put it) invoked in the analysis of primary substances, but they are not themselves primary substances. They cannot exist on their own. Let me explain.
An ordinary 'sublunary' particular such as a man, a horse, a tree, a statue, a 'primary substance' in Aristotelian nomenclature, is a this-such. The thisness in a this-such is the determinable element while the suchness is the determination or conjunction of determinations that determines (delimits, characterizes, and informs) the determinable element. Veatch's point is that the determinable element cannot be an ontological atom, an entity more basic than the composite into which it enters; it is not an ontological building block out of which, together with other such 'blocks,' the this-such is constructed. The determinable element cannot be a basic existent; it must be a principle of a basic existent, where the basic existent is the this-such. And the same holds for the determining element, the form.
This implies that what is ontologically primary is the individual substance, the this-such, which entails that matter and form in an individual substance cannot exist apart from each other. They are in some sense 'abstractions' from the individual substance. They are nonetheless real ontological factors, as opposed to theoretical posits having a merely mental being; they cannot, however, exist on their own. They are not themselves substances. That is what I mean by my use of 'abstractions.'
But what exactly is a (primary) substance?
A substance is a thing to which it belongs to be not in a subject. The name 'thing' (res) takes its origin from the quiddity [quidditas = whatness], just as the name 'being' (ens) comes from 'to be' (esse). [Ens is the present participle of the infinitive esse.] In this way, the definition of substance is understood as that which has a quiddity to which it belongs not to be in another . (Aquinas, Summa Contra Gentiles, Bk 1, Ch 25)
The form and the matter of a material substance, then, are are not themselves substances because it does belong to them to be in another, namely, in the substance of which they are the form and the matter. Hylomorphic dualism is not a dualism of substances. Here we appear to have an important difference between Aquinate and Cartesian dualism. But the difference may be less than at first appears.
Now the form in a material this-such is not merely tied to matter in general, in the way that Bergmannian first-order universals are tied to Bergmannian bare particulars in general; the form is tied to the matter of the very this-such in question. This is because Aristotelian forms are not universals. And the same goes for the matter: the designated matter (materia signata) of Socrates is tied to the very form that is found in Socrates: that parcel of matter cannot exist apart from Socrates' substantial form. The two ontological factors (as I call them) are necessarily co-implicative. Neither can exist without the other. The two together constitute the individual substance, which is being in its most basic sense. For Aristotle, "being is said in many ways," to on legetai pollachos, and the most basic sense is being as substance (ousia). Aristotelian ontology is ousiology. (Aristotle, Metaphysics, 1028b4)
I said that hylomorphic dualism is not a dualism of substances, and thus that it appears that soul-body dualism in Aquinas is very different from soul-body dualism in Descartes. But the picture is complicated by the Thomist doctrine that the souls of rational animals, unlike the souls of non-rational animals, are subsistent. What this means is that human souls are capable of existing in a disembodied state. This capacity is exercised at death when we humans shed our bodies. We continue to exist as disembodied souls and thus as matter-less forms. But now a tension, if not a contradiction, comes into view. It is not clear how all of the following propositions can be true:
a) The form of a material substance is not itself a substance, but a principle that cannot exist on its own, but only in tandem with a material factor together with which it constitutes a substance. A form-matter composite is not constructed from pre-existing 'building blocks.'
b) The souls of humans are not substances along Platonic-Augustinian-Cartesian lines, but forms of the bodies whose souls they are.
c) The souls of humans are subsistent forms that can exist on their own after the deaths of the bodies whose forms they are.
Can someone explain how all three propositions could be true? On the face of it, the first two, taken together, entail the negation of the third. What we have here is an inconsistent triad. Although collectively inconsistent, the members of the triad are individually plausible. Why plausible?
(a) is plausible given that (i) there is such a thing as ontological analysis and (ii) its style is hylomorphic. The authority of philosophus, The Philosopher, as Aquinas calls him, stands behind (a). The authority of Aristotle may also be invoked in support of (b) if the soul (anima, psyche) of a living thing is its life-principle. (The soul animates the material body of an animal, making it alive.) As for (c), it is a Christian commitment of the doctor angelicus that he cannot abandon.
The three propositions are collectively inconsistent but individually plausible. We've got ourselves a problem. Something has to give.
It has been said that Aquinas is a Platonist in heaven, but an Aristotelian on earth. These super- and sub-lunary tendencies comport none too well. One solution is to drop the Aristotelianism with its combined commitment to (i) hylomorphic ontological analysis and (ii) soul-as-life-principle and go the Platonic-Augustinian-Cartesian substance-dualist route. Richard Swinburne exemplifies this approach in Are We Bodies or Souls? (Oxford UP, 2019) A second solution would be to drop the Christian commitment to the immortality of the soul and embrace a form of materialism about the human person. A third solution would be to somehow uphold Christianity while accepting materialism about the human person. (See my Could a Classical Theist be a Physicalist?)
What other solutions are there?
Professor Vallicella, you are coming close in this article to something that has always bothered me about the Aristotelian-Thomistic approach to human ontology. ‘Anima forma corporis’ seems to be read as ‘anima forma hominis’. However the ‘forma corporis’ has to be something other than the rational soul. For my money the ‘forma corporis’ has to be an animal soul such as is possessed (mutatis mutandis) by all living things, and separable and separate from the rational soul (spirit/mind/consciousness/ego/etc). This implies the doctrine of trichotomy, which was rejected by Augustine and, following him, by Aquinas.
With inanimate things, form supplies the whatness of the thing, while matter supplies the thisness. Form categorises; matter individuates. However it is not the matter of my perishable body that individuates me, but my imperishable soul. Just one of the reasons why, when push comes to shove, I am a Platonist rather than an Aristotelian!
Thanks for the comment, Mr. Barber.
>>For my money the ‘forma corporis’ has to be an animal soul such as is possessed (mutatis mutandis) by all living things<< That is the way I understand it. anima formal hominis is a special case of anima forma corporis at least if the bodies in question are animal bodies. I am not clear whether Aquinas thinks that plants, which are living things, have souls.
>> . . .and separable and separate from the rational soul (spirit/mind/consciousness/ego/etc).<< I agree: the soul as life-principle cannot be identical to the rational soul. The soul of a cat is its life-principle, but surely such a soul is not rational. I suspect that Aquinas gets into trouble because he assigns to the human soul two very different jobs: it is the animating principle of the human body but it is also the subject of my mental states (whether sensory or intellectual). It is that in me which thinks (in the broad Cartesian sense of cogitare) when BV thinks. I do not understand how both of these jobs can be performed by the soul as life-principle.
I also don’t understand how Aquinas can say that the life principle in us is subsistent, but not subsistent in the other animals. That strikes me as an offensively ad hoc move.
I am not familiar with the doctrine of trichotomy. Perhaps you can explain it to me. I think i know what you mean, but I want to be sure. Am I illicitly conflating Augustine with Aquinas on this point?
But I think we are zeroing in on the same problem. In broad terms, the approach of Aristotle and Aquinas is objectivistic and ‘naturally attitudinal’ (Husserl) and for that reason inadequate: they have yet to achieve the transcendental POV that surfaces in explicit form in Descartes and is pushed forward by Kant (whom the better Thomists, the transcendental Thomists, appreciate). Yes I am being tendentious. I invoke my blogospheric privilege.
I say “surfaces in explicit form” because already in Aristotle, in De Anima there is that amazing passage in which he says that the soul is in a certain sense all things. Now surely no animal’s life principle, not even that of a human animal, is in any sense all things. The transcendental motif is already in Aristotle.
Does Aquinas say anything about the De Anima passage in his commentaries on Aristotle?
Jonathan,
>> With inanimate things, form supplies the whatness of the thing, while matter supplies the thisness. Form categorises; matter individuates. However it is not the matter of my perishable body that individuates me, but my imperishable soul. Just one of the reasons why, when push comes to shove, I am a Platonist rather than an Aristotelian!<< You are on to something important here. What makes me an individual? What is the individuator of a human being? On Aristotle's objectivistic/naturalistic scheme, the problems of individuation and differentiation appear to be conflated: the individuator = the differentiator. What makes two material particulars, Socrates and Plato, numerically different is signate matter. But it cannot be signate matter that makes each of these men the unique individuals that they are. Hylomorphic analysis works with things like statues. Two statues with the same substantial form are individuated and differentiated by the same ontological factor, materia signata. But you and I are spiritual beings unlike statues and animals. What makes each of us a unique individual cannot be either substantial form or signate matter. And since we are more than animals, it cannot be a life-principle that makes each of us unique. This is because, as unique persons we needn’t be biologically alive. When we are dead souls we obviously won’t be alive and in need of a life-principle.
The spiritual principle has to be other than a principle of biological life. And so we are pushed in a Platonic direction.
We need a tripartite distinction: life-principle, spiritual principle, ultimate subject of mental states.
Oner question that arises is how the third item differs from the second. Or are they oner and the same?
Bill,
“I also don’t understand how Aquinas can say that the life principle in us is subsistent, but not subsistent in the other animals. That strikes me as an offensively ad hoc move.”
For those interested in your thinking on this matter, I think it useful to call attention to two earlier, excellent Maverick Philosopher posts, “Are the Souls of Brute Animals Subsistent?” (December 2009) * and “Soteriology for Brutes” ** (March 2019).
Vito
*https://maverickphilosopher.typepad.com/maverick_philosopher/2009/12/are-the-souls-of-brute-animals-subsistent.html
**https://maverickphilosopher.typepad.com/maverick_philosopher/2019/03/soteriology-for-brutes.html
Bill,
I have a question that arises from thinking about your second response to Jonathan: If, according to Aquinas, a soul is individuated and distinguished from other souls because of its relation to the specific portion of matter (materia signata) in which it exists, then how after death without this matter can it be ontologically different from other disembodied souls? Very strange.
Vito
while i understand the classical tension between ockham, scotus, and aquinas, on the principal of individuation for human beings, i don’t fully understand why one is needed at all.
what makes the number 1 different from the number 37?
what makes the property “being red” different from the property “being blue”?
i don’t know that i’m convinced of the reality of haecceities, but i think i lean in that direction.
Vito,
Aquinas’s reliance on Aristotle commits him to hylomorphism, which works well with material things such as artifacts e.g. statues and non-human living things. But it doesn’t work in our case. For we are not merely animals, and our souls are not mere life-principles. What’s more, each of us has his own spiritual soul. But then what is the principle of individuation/differentiation of spiritual souls that can exist immaterially?? Can’t be signate matter!
John,
>>what makes the property “being red” different from the property “being blue”?<< In this case the qualitative difference suffices for numerical different. In the case of two spiritual souls, there is qualitative sameness but numerical difference. What is the ground of that numerical difference? Can't be signate matter!