Substance dualism is the philosophical position that the mind is composed of a fundamentally different substance than is the body, and therefore the functioning of the mind cannot be explained or understood in terms of physical entities and processes. While it has roots going as least as far back as classical philosophers like Plato, it is probably most strongly associated with Rene Descartes. Today, the position is a decidedly minority one among philosophers of mind and neuroscientists. In large part, this is simply a reflection of the prevailing attitude, particularly in intellectual and academic circles, which does not take seriously claims of the immaterial and supernatural. But there are also specific problems with substance dualism that, while long recognized, remain insuperable.
Prominent among these is the problem of interaction, which can be summarized as follows: The mind is clearly able to have effects on things that are material. It can cause us to move our arms or legs, and to speak. Its emotions can have effects on our pulse and rate of breathing, etc. Yet if the mind has no physical attributes or qualities, how does it interact with the physical world in order to have these effects?
I have recently come across an attempt to address this problem by a proponent of dualism (who, however, does not claim to be a Cartesian dualist). OK, I admit: It is my arch-nemesis Michael Egnor. (The poor guy is going to think I’m stalking him.) He has written an article on the Discovery Institute blog Mind Matters, entitled “How Can Mind Interact With Matter?”, in which he appeals to the concept of hylomorphism to solve the problem.
Hylomorphism is an idea attributed to Aristotle, and its basics are fairly simple to understand. Aristotle is concerned with the question of what happens when things change into other things. He rejects the idea be that one thing ceases to exist, and is replaced by another thing, because this would mean that the second thing would have come into being out of absolute nothing. On the other hand, during the process of change, something must have been lost, or ceased to exist, to be replaced by something new. Aristotle refers to that which persists as matter, and to that which is acquired through the process of change as form. Together, these comprise a thing’s substance. A simple example to illustrate the concept: Imagine a bronze statue of a horse that is melted down, and then recast into a statue of a man. Here, the matter is the bronze, and the form is (initially) that of a horse, which is then replaced with the form of a man.
This is all straightforward enough when we are talking about simple inanimate objects of this sort. However, things become rather more complicated when we attempt to apply the concept to issues like the nature of the relationship between the body and the mind. Aristotle considered the matter of a human being to be the body, and its form to be the soul. But, at the same time, he held that a body that has lost its soul (i.e. after death) is no longer a body, i.e. that the soul is an essential aspect of a body, and without it the body ceases to be. Therefore, there seems to be an inconsistency in Aristotle’s treatment of matter and form as distinct aspects of a substance which are related only contingently to one another. 1 There remains disagreement to this day over whether Aristotle’s was a monist or dualist view of the mind/body relationship. It is clear, however, that he did not accept Plato’s view of forms as transcendent, timeless, immaterial entities that exist separately from the objects that manifest their qualities.
Regardless, it is difficult to see how, taken on its own, Aritotle’s hylomorphism provides a solution to the interaction problem. So how does Michael Egnor attempt to use it as such? Here is what he writes:
(M)atter and spirit interact in the same sense that matter and form interact. Form is the organizational principle–the intelligible principle–behind the thing. Matter is what individuates something. Form is what makes it real rather than potential. Form determines the properties of matter.
A simple example from chemistry will help: It is the property of certain things to exist as mirror images of each other; my right and left hand are an obvious example. From the standpoint of matter, my hands are identical. They have the same bones, muscles and nerves. What makes them different is their form. My right hand is a mirror image of my left hand. That is, it is the form alone—the organization of my hand—that makes the difference, rather than the matter of which my hand (right or left) is composed.
Chirality is a property of asymmetry. The same chirality exists in many molecules and chirality plays an essential role in biochemistry. Most biomolecules are chiral, and the function of biomolecules is tightly linked to their chirality. “Right-handed” glucose is metabolized by the body. “Left handed” glucose is not….
The relevance of chirality to substance dualism and the interaction problem—how can something immaterial interact with something material—is that chirality is a beautiful example of how form alone—immateriality—can determine the properties of matter.
I think the problem with his argument is plain, but I will nonetheless spell it out: The chirality of a molecule is a physical attribute. It is reducible to the spatial arrangement of its constituent atoms in physical space. It does not require us to invoke mysterious, immaterial, supernatural processes or forces to account for the fact that, when chemicals undergo reactions to form new compounds, the latter will demonstrate properties that were not present in the former.
A further problem: Egnor appears to equate matter with the “material”, and form with the “immaterial.” He views the “spirit”, by virtue of its providing the form of the mind, as immaterial, with the material brain providing the mind’s matter. However, the brain is, itself, composed of more basic physical constituents. So would it not be correct to consider the physical structure of the brain to be its form, and the cells and other tissue that make it up to be its matter? I cannot see why not. But, if that is the case and Egnor is correct in equating form with the “immaterial”, then we have the odd situation in which the brain is both material (with regard to the “spirit”) and immaterial (with regard to the cells that make it up). That does not make any sense, and suggests that Egnor is incorrect in his equation of form with the immaterial.
As I had mentioned, there remains disagreement among scholars regarding the exact nature of Aristotle’s position on the mind/body question. As it happens, at least one contemporary philosopher, William Jaworski, appeals to hylomorphism as a possible solution to the hard problem of consciousness, and draws an analogy between those who would insist otherwise and adherents of the discredited concept of vitalism: writing: “(T)he hard problem of consciousness does not arise within a hylomorphic framework. It arises only for a view of the natural world that rejects hylomorphic structure. If conscious experiences are structured activities, as hylomorphism claims, then they can be exhaustively accounted for by describing the powers of conscious beings, the subsystems in which those powers are embodied, and the kind of coordination or structure that unifies the activities of those subsystems into conscious events. To insist that such a description fails to capture phenomenal character is analogous to an obstinate vitalist claiming that a physical description must fail to explain life because it fails to accommodate vital spirit. “2 I am not endorsing Jaworski’s viewpoint nor claiming that he has succeeded in solving the “hard problem.” I am merely pointing out that, at the very least, it would appear that hylomorphism is a double-edged sword that can be used to argue against dualism, and that by merely invoking the concept Egnor has not demonstrated that dualism is a viable position . (BTW, be forewarned that if you Google William Jaworski’s name, many of the hits will pertain to sexual harassment claims that have recently been made against him. Not that this should have any bearing on the validity of his arguments, but I just thought I should mention that).
Now, it is entirely possible that I am taking Egnor too literally and he is only using examples such a chirality as metaphors for how he understands hylomorphism to pertain to the relationship between mind and body. But if that is the case, it is not at all clear what this metaphor is meant to represent. With any luck, he will read this article and clarify what he means. As things stand, however, I do not think he can justifiably claim to have resolved the problem he has set out to resolve.
I’ll read this when I am well.