Some questions on the soul, Part III

In some recent posts I’ve been answering readers’ questions about the Aristotelian-Thomistic (A-T) understanding of the soul.  One more for the road, from a reader who is unclear about why mind-body interaction, which is notoriously problematic for Cartesian dualism, is not also problematic for A-T.  The reader writes:

[U]nless something like dualist interactionism is true, I don't see how… immaterial thoughts and - in particular - the will - could possibly cause me to do something as simple as typing this e-mail…

Science would seem to say that the efficient cause of this was certain electrochemical reactions in my body.  The material cause would be the physical events happening in my body.  It seems that A-T philosophy would hold that the final cause was getting an answer to a philosophical question, and I agree.  My soul would then be the formal cause, but I guess that notion is incoherent to me… And, unless the immaterial mind somehow interacts with my body (through quantum physics, maybe?), I don't see how my thinking about something in my immaterial intellect could cause my body to do anything.

End quote.  My goodness, can you believe the kids today, with their Cartesian interactionism!  Seems to be sweeping the country, as you can see from the photo above.  What’s next, epiphenomenalist keg parties?  (“Dude, don’t tell me I’m too hammered to drive home!  My feeling drunk was caused by all the beer in my system, but it has no causal efficacy of its own in turn.  So I’m cool.  If I get pulled over I’ll just slip a copy of Jackson’s ‘Epiphenomenal Qualia’ to the cop.”) 

Seriously, though, the first thing to say in response is that the reader seems to think that when I deny (as I have often done) that there is an interaction problem for A-T, I am denying that mind and body interact.  But I do not deny that they interact.  I just deny that this interaction is a problem for A-T, as it is a problem for Cartesian forms of dualism.  Indeed, it was (as we will see below) Cartesianism that made mind-body interaction problematic in a way it had not been on the A-T view, which makes it ironic that the reader should suggest that Cartesianism is somehow “coherent” in a way A-T is not. 

But perhaps the reader’s worry is related to an objection once raised by Bill Vallicella.  Citing what I say about our subject in my book Philosophy of Mind, Bill writes:

Feser here makes two main points. The first is [that] the soul-body relation is a special case of the form-matter relation; as such, the former is no more problematic than the latter. The second point is that the relation between soul and body is one of formal, not efficient, causation. The two points are logically connected: if the soul is the form of the body, and if the two are causally related, then it is difficult to see how the relation could be one of efficient causation. An efficient cause is either an agent-cause or an event-cause. But forms are neither agents nor events.

Bill goes on to object:

I honestly do not see how hylomorphism solves the problem of interaction… [I]nteraction is, by definition, efficient-causal interaction.  Mental events bring about physical events and physical events bring about mental events. To interpret this interaction in terms of formal causation seems tantamount to denying that there is any interaction. Iteraction is efficient-causal interaction. Formal causation appears irrelevant to it…

[For] example, my sudden remembering of having been given a bottle of Scotch is an event-token that enters into the etiology of my rising from my chair. It is rather unclear how this event could be the form of anything in the body. For one thing, the event of remembering is temporally prior to any of the events involved in my rising from my chair. Forms, however, are not temporally prior or posterior to what they inform. So it seems clear that a mental event cannot stand to a physical event it causes in the relation of form to matter.

End quote.  Now the trouble here, I would say, is that Bill is getting the A-T view only partially right.  For A-T, the human soul is the substantial form of a human being, that which grounds our characteristic activities as rational animals -- nutrition, growth, reproduction, sensation, appetite, locomotion, intellect, and will.  The soul is thus related to the body as form to matter, and thus, as Bill indicates, it is perfectly correct to say that the soul and the body do not interact, since they are not separate substances but rather two principles of one substance, viz. the human being.  So far so good.  However, that does not entail that the mind and the body cannot be said to interact -- or more precisely, that mental states and processes cannot be said to interact with bodily states and processes.  That would follow only if, like the Cartesian, we identified the mind with the soul.  But of course, A-T does not do this.

The mind is rather a power of the soul; to be more precise, intellect, imagination, sensation, and will are distinct mental powers of the soul.  Or to be even more precise, these are mental powers of the sort of substance -- the human being -- having a soul or substantial form of the sort we have.  And particular episodes of thinking, imaging, remembering, perceiving, etc. are exercises of those powers.  They can be said to “interact” with or efficiently cause bodily motions of the sort involved in writing an email or getting up to pour some Scotch in something like the way a tree’s roots “interact” with its branches by virtue of taking in water that travels to the branches.  In each case the exercise of a substance’s powers has an efficient-causal influence on the later exercise of other powers.

Now like us, a tree is one substance, and like us it has its own substantial form, which grounds its characteristic powers and operations.  It is this same one substantial form that is responsible for the tree’s taking in water through the roots and the branches’ transferring it to the leaves, for roots and branches are not themselves substances but only parts of a substance.  We can speak loosely, however, of the form of the roots and the form of the branches, since roots are different kinds of part from branches.  We can say that it is the form of the roots that makes them capable of doing their job of stabilizing the tree, taking in water, etc., and it is the form of the branches that makes them capable of doing their different job of transferring water, growing leaves, etc.  And these parts’ having these different forms will entail their having all sorts of structure that allows them to do the jobs they do.  Having the form of branches, for example, will entail being made up of wood and bark of such-and-such a structure, whereas having the form of a leaf will entail having a very different structure of the sort necessary for photosynthesis.  The parts interact the way they do because of the complex structures and activities entailed by the forms each part has, which is ultimately a matter of the whole tree being informed by the kind of substantial form it has.

Now something similar can be said of a human being.  It is one substantial form or soul that informs the whole human being and grounds all of its characteristic powers and operations.  But there is a looser sense in which we can speak of the form of a leg as opposed to that of a heart as opposed to that of an eyeball, and it is these parts’ having the different forms they do that allows the parts to interact in just the ways they do (e.g. the heart pumping blood to the legs, etc.).  That in turn requires all of the parts to have various structures that enable them to carry out the jobs associated with their forms (e.g. the heart must be made out of muscle, the legs are composed of muscles, bones, and tendons, etc.).

But the same thing is true of mental faculties and activities.  The form of remembering something is different from that of desiring something, which is different in turn from that of believing something.  And different structures will follow from a mental state’s having these different forms.  In particular, for A-T each of these will involve a conceptual component but also the having of certain phantasms or mental images, and this in turn will require certain kinds of brain activity.  Just as to have the substantial form of a tree entails carrying out photosynthesis and thus the having of organs with the form of a leaf which in turn entails having various structures characteristic of a leaf, so too does having the substantial form of a human being entail carrying out operations like remembering, which entails having both concepts and phantasms, which in turn entails certain kinds of brain activity.  Ultimately a tree and its activities are explained by reference to the substantial form of a tree; but proximately the activities of a root or leaf are to be understood by reference to the way that the matter of these organs is informed by the forms of these organs.  Similarly, ultimately a human being and its activities are to be explained by reference to its substantial form or soul; but proximately the heart’s pumping of blood or a person’s remembering something are to be understood by reference to the way the matter underlying these activities is informed by the form of the heart or the form of remembering something, with its own characteristic intentional and qualitative content and with its own characteristic associated brain activity.

Now let’s come back to Bill’s example of remembering the Scotch and getting up to go pour a glass of it.  The trouble is that his scenario is both under-described and mis-described -- that is, it gives too little detail and gets a crucial detail wrong where it does give details.  Yes, the form of remembering something cannot plausibly be regarded as the efficient cause of the later event of a person’s walking across the room, both because it is a formal rather than efficient cause and because the remembering of which the form is a form is temporally prior to the walking.  But the A-T philosopher would not say in the first place that the form of remembering is the efficient cause of the walking. 

The right thing to say is rather this.  There is, first, the event (call it A) of remembering the Scotch, which involves the matter of the brain and body being informed in the way characteristic of remembering, which in turn entails a certain conceptual content, certain phantasms, certain underling brain activity, etc.  Then there is the later event (call it B) of walking across the room, which involves its own characteristic form and thus in turn its own characteristic conceptual content, phantasms, brain activity, etc.  Now Bill speaks as if what the A-T philosopher is saying is that the formal cause of A (i.e. the form of remembering) is the efficient cause of the material cause of B (i.e. the moving of certain body parts as one walks across the room).  That is a complete muddle, of course, but it is also not at all what the A-T philosopher is saying.  What A-T is saying is rather that event A, which has the form of remembering as part of its complete description (where the other parts of a complete description include a material cause that entails having certain phantasms and brain activity), is part of the efficient-causal story behind event B, which has its own formal and material causes (including the motions of certain muscles as one walks across the room and the brain activity accompanying this).  In short, A, by virtue of its formal and material causes, serves as a (partial) efficient cause of B, which has its own, different formal and material causes.  (There are also other efficient causes involved -- such as a person’s feeling of pleasure at the thought of drinking the Scotch -- and final causes as well, such as the end or goal of drinking the Scotch.  But we needn’t get into all that in order to address the specific issue at hand.)

Now Bill, no less than the reader I quoted above and no less than the materialist, will no doubt be happy to allow that it is not mysterious how physiological activity of the sort associated with phantasms can causally interact with physiological activity of the sort associated with walking over to the Scotch or writing an email.  But then it should be in no way mysterious how, on the A-T view, mental events like one’s memory of the Scotch cause bodily events like walking toward the Scotch.

But doesn’t this threaten epiphenomenalism?  For isn’t the physical aspect doing all the causal work, with the mental aspect just coming along for the ride?  Emphatically No and No.  To think so is just to read into the A-T account a Cartesian/materialist conception of matter of precisely the sort A-T denies.  If we supposed that there is nothing more to matter than what mathematical physics tells us, or nothing more to brain activity than what we might put in terms of the wiring and firing of neurons and the like, then it might seem that to say that physical or brain event A is the efficient cause of physical or brain event B is to leave nothing for anything else, including any mental aspects of the situation, to do.  But of course, A-T denies that there is nothing more to matter than what mathematical physics tells us, or nothing more to brain activity than what we might put in terms of the wiring and firing of neurons.  A-T insists that a complete description of any physical or physiological object, system, event, or process is going to make reference to each of the four causes, to the actualization of potency, and indeed to the whole apparatus of A-T philosophy of nature.  A description of matter only in terms of mathematical physics or of the brain only in terms of the wiring and firing of neurons is only ever a partial description in the first place, an abstraction from a much richer concrete reality that cannot in principle be captured merely in terms of the categories of physics or neuroscience (even though those categories are fine as far as they go).   A wouldn’t be able to generate B in the first place if there weren’t formal- and final-causal aspects to its complete description in addition to the efficient- and material-causal aspects; and even the efficient- and material-causal aspects are understood on A-T very differently from the way they are on a Cartesian or physicalist account.

Properly to understand the A-T approach to the interaction problem, then, one must see it in light of this larger, and very radical, rejection of the entire conception of nature and of matter that is taken for granted in the usual debates between Cartesians and materialists.  It is by no means a matter of accepting the basic terms in which Cartesians and materialists debate mental causation, but merely throwing in a little talk about formal cause and material cause.  It seems to me that neither Bill nor the reader who raised the question quoted above take sufficient account of this.

They also, it seems to me, take insufficient account of how deeply the interaction problem is tied to a specifically post-Cartesian understanding of mind and body.  As I have noted before (e.g. here and here) Descartes’ conceptions of res cogitans and res extensa were arrived at by reifying two abstractions.  First Descartes abstracted out from concrete material substances those features that were definable in terms of mathematical structure alone, reified that abstract structure -- making of what is really only an accident or characteristic of a substance a substance in its own right -- and then stuck the label “matter” onto this invented substance.  Second, he abstracted out from human beings their power of thought, reified that abstraction -- making of what is really only a power of a substance a substance in its own right -- and then stuck the label “mind” onto this invented substance. 

This created an interaction problem in several ways.  First, the new Cartesian conception of matter -- a conception which, certain details aside, the materialist essentially endorses himself insofar as he thinks mathematical physics gives us an exhaustive description of matter -- made of matter something essentially inert.  For there is nothing in the language of mathematics that can capture anything like the active potency or causal power that the Aristotelian-Scholastic tradition Descartes and the other early moderns were rebelling against attributes to matter.  This is why Descartes and others took to thinking of motion as something that had to be imparted to matter from without, by God.  It is also part of the reason even body-body interaction -- never mind mind-body interaction -- became problematic for the early moderns.  Indeed, Descartes appears to have been an occasionalist with respect to body-body interaction, attributing causal interaction to the mind-body case alone.  Malebranche’s more thoroughgoing occasionalism and Leibniz’s parallelism -- both of which, remember, denied causal interaction in the case of physical objects no less than the mind-body case -- were just more consistent applications of the basic Cartesian position.  And Humeanism vis-à-vis causation was just the last stop on the train Descartes and Co. had sent out of the station.  Causation as such becomes problematic when one denies (as the early moderns generally did) Aristotelian notions like active and passive potency, finality or the directedness of efficient causes toward their characteristic effects, and related notions.

Second, the modern idea that the material world characterized exclusively in mathematical terms is causally closed (where efficient causation is what is in view in casual closure) leaves nothing for mental states qua efficient causes to do. 

Third, making of thought a substance in its own right makes it mysterious how the human mind can interact with the body in the specific manner in which it does -- specifically, in such a way that mind and body make up an organic whole.  The mind, in Cartesian dualism, seems instead to relate to the body the way a fallen angel relates to some human being, animal, or inanimate object it possesses -- as something to which it is no more essentially related than it is related to any other material object.  This is the reason Ryle famously, and rightly, characterized Cartesianism as the theory of the “ghost in the machine.”  A machine would be just the thing it is, and a poltergeist just the thing it is, whether or not the latter haunted the former.  They are related only contingently and do not form a unity.  But the same is true of mind and body on a Cartesian account.  The mind is essentially like an angel -- which for A-T is a thinking substance -- and the body is essentially a zombie, in the philosophy of mind sense.  Each could be exactly as it is even if the other were not in the picture.  Hence even if some kind of causal relation could be said to hold between them, it wouldn’t be the right kind.  For the mind is not in fact related to the body as a kind of chess piece or tool that it moves around, which is the way a poltergeist moves an object around. 

Thus, when you see and hear, you perceive the world from the point of view of the body and its sense organs -- from a perspective just behind the eyes and between the ears, as it were.  When your body is warmed, cooled, or damaged, you feel the temperature or pain in the affected body part.  When you pick something heavy up or climb a hill, you feel the strain in your arms and legs.  By contrast, when you operate a model airplane via remote control, you don’t see and hear the world below the airplane as if from its point of view; when the poker with which you move around logs in the fireplace glows red, you don’t feel that heat in the end of the poker; and when the end of a screwdriver breaks off as you try to remove a rusted screw, you don’t feel the snap in the screwdriver’s tip.  (Of course, you might feel some warmth in your hand as you use the poker, or feel a vibration as the screwdriver breaks, but that is different.  What you feel in that case is in your hand, not in the poker or the screwdriver.) 

Now a poltergeist or an angel moves about a material object in something like the way we move about these instruments -- as something extrinsic, to which the mover is related only contingently.  If the mind were related to the body in the way Descartes supposes, that is how the human body would seem to us.  And yet it doesn’t seem that way at all.  On the contrary, it seems instead to be part of us, as we would expect if, as A-T maintains, a human being, mind and body together, is one substance rather than two.

In the post linked to above, Bill suggests that the interaction problem for Cartesian dualism is overrated given that there are accounts of causation, such as regularity theories and counterfactual theories, on which mind-body interaction is no more problematic than any other kind of causal relation.  But this doesn’t show that Cartesian dualism is in good shape after all; on the contrary, it shows at most only that all causation, as the moderns understand causation, is in shape as bad as mind-body interaction is given Cartesianism.  For regularity theories and counterfactual theories are essentially Humean theories.  They face notorious problems, and you don’t have to be an Aristotelian to think that they do not really capture causation at all, but only a post-Humean ersatz.  The “causation” they give you is like the “law and order” that an Al Capone-style mob boss might give you once he takes over the city and makes sure that his gangsters keep the streets safe for their operations by rubbing out other, lesser thugs.  In both cases what we have are really symptoms of the basic problem, not solutions to it.