One would expect a book on this broad subject to leave some dangling issues. Dr. Feser’s sympathies clearly lay with Aristotelian dualism, even theism. He begins with a nuanced statement of Cartesian Substance Dualism. His aim is to explicate the logical strength of substance dualism, aware also of its primary weakness (the “interaction problem”) and then ask if the various alternatives to it, particularly those promulgated by materialist philosophers of the 20th and 21st centuries, are coherent in their own right and if so, successfully defeat dualism’s logic.
As noted in the review (reproduced below with a link to the book on Amazon) Feser spends the bulk of the book on this latter task. He demonstrates that none of the suggested alternatives actually work. Some (eliminativism of two kinds and epiphenominalism) are incoherent, while others (functionalism, behaviorism, and many others) fail to capture the substance of subjective first person experience, in effect explaining it away. Most of these critiques focus on epistemological issues, but some also run into metaphysical issues, indeed the same “interaction problem” faced by Cartesian dualism (see also “From What Comes Mind” and “Fantasy Physics and the Genesis of Mind”).
Having demolished the contenders, Feser asks if there is something else, a different sort of dualism that might work and yet not require or point to theism? His solution is Aristotelian Hylomorphic dualism. Alas, as noted in the review, here he fails but doesn’t seem to notice it. Either the form emerges from the facts of the assemblage that is the brain, or it is added intentionally from the outside. Hylomorphism either collapses into reductive (or supervenient) materialism, or it leads back to something that must stand in the place of, if not be, God. Feser leaves this matter dangling.
Other issues dangle. Feser cites many authors I’ve read, among them David Chalmers, but as I read Feser, he seems to misunderstand Chalmers’ “property dualism”, more or less equating it with epiphenomenalism, the idea that our mental arena is merely an accidental by-product of brain function with absolutely no causal consequence. It is precisely the point of Chalmers’ property dualism that it does have causal consequence and so is not epiphenomenal but rather a radical emergence.
From the physics of brains alone emerges what amounts to a substance with novel properties, the upward property of subjective experience itself, and a downward causal power, subjective will, on that same physics. Chalmers, being bothered by the radical character of the emergent subjectivity, speculates on panpsychism or various types of monisms that might be embedded in physics and so support such an emergence (see above linked “Fantasy Physics…” essay for details). These various ideas for sources of the phenomenal in a hidden property of the physical are quasi-material in Feser’s taxonomy.
Another matter of interest to me is Feser’s characterization of substance dualism. His sketch is more nuanced than that usually given by his materialist peers but there are other possibilities that yet remain broadly Cartesian. For example, a property dualism supported by the presence of a spacetime field that is not physical but also not phenomenal (or proto-phenomenal).
The field need not be mind as such. It need have no phenomenal/proto-phenomenal properties of its own. Viewed from the material, mind is a radical emergence (upward) and has, as a result of its novel properties, also downward causal qualities. Its appearance, however, its form and nature, is the result of an interaction with this everywhere present (and yes, mysterious) field and not equally mysterious undetectable properties embedded in physics. For a detailed explication of this model see my “From What Comes Mind?”
Of course an “interaction problem” comes immediately forward. This hypothetical field is, after all non-material. But this interaction issue is the same faced by property dualism generally along with panpsychism, and Russelian or dual-aspect monism. All of these theories propose proto-phenomenal properties embedded in micro physics or the universe as a whole, but none ever say how exactly to identify the proto-phenomenal, in what exactly its properties consist. Nor do they speculate on their origin, and how they interact with the physical we know; how exactly they perform their teleological function driving the physical towards [genuinely] phenomenal expression.
Feser notes that materialist philosophers always cite “Occam’s Razor” as reason for rejecting theism and so any sort of substance dualism. He should somewhere have noted Occam’s Razor is supposed to apply to two or more theories that equally explain all the data! Theism answers two of the questions left dangling by quasi-materialisms. It explains why it is we find the phenomenal, any phenomenal proto or otherwise, only in association with brains. It has also an origin story in theistic intentionality, the phenomenon we find at the core of the recognizably phenomenal, our phenomenal, itself!
Quasi-materialisms deny intention in the proto-phenomenal leaving the transition to intention in brains hooked (metaphysically) on nothing. None of this, not the postulation of a field or the proto-phenomenal explains how exactly interaction occurs. The problem with theism isn’t merely the interaction (about which at least “God knows the trick”) equally suffered by all the non-eliminative materialisms. The problem is the postulation of an intentional source of the field supporting intentionality as we experience it. Yes this is a big pill to swallow, but without it we can say nothing about how any of this works anyway. Rejecting the possibility of theism leaves behind more mysteries than it resolves.
Surely suggesting that there is an intentional (minded) source of intentional, subjective mind begs the question. Of course it does! It remains, however, a coherent, possibility! God can not only be conceived, his necessary qualities can be specified to considerable detail (see my “Prolegomena to a Future Theology”). It isn’t clear that the proto-phenomenal can be conceived, and even if we allow its conceivability there seems to be nothing that can be said at all about any of its qualities.
I said at the end of the book review I would say something about free will. Feser does not mention it. Free will is related to intentionality. The ability to direct our attention purposefully is the core of the matter and some (Schopenhauer) would say it, is the essence of the conscious self! “Mental causation” or in Rescher’s terms initiation is, when not subconscious, agent-directed. We experience our agency as will (and this why the ‘free’ in ‘free will’ is redundant’ see “All Will is Free”). Will’s relation to “philosophy of mind” should be obvious. We experience our volitional agency in mind, and like qualia and intention, the nature of volitional agency is mysterious, doubly so because it is a mystery on top of a mystery!
I have said much about free will and its associated agency elsewhere in the blog. On the negative side (the absurdity of denying it) see “Arguing with Automatons”, and “The Nonsensical Notion of Compatibilism”. On the positive side, “Why Free Will”, “Why Personality”, and “The Mistake in Theological Fatalism”.
The two best books on the subject are “Free Will: A Philosophical Reappraisal” by Nicholas Rescher and E. J. Lowe’s “Personal Agency”. My own books, “Why this Universe” and “God, Causal Closure, and Free Will” both address the subject.
I picked up Feser’s “Philosophy of Mind”, a book in an introductory series, for the sake of little else to read at the time, but I’m glad I did. It is, perhaps the best basic-evaluation of this subject (one of my specialty areas) I have ever read. It doesn’t merely introduce and review the subject. It makes an argument, a point about the present philosophical state-of-the art on the nature of mind, and does it very well.
Feser begins by introducing the subject and settles on representative-realism (the external world is real more or less as we experience it, but what we experience as subjects is nevertheless a representation of it) as the fundamental datum which a philosophy of mind must account. He then moves to examine the various proposals put forth by modern philosophers, some with their roots back in classical Greek times. He begins with Cartesian (substance) Dualism, a rather more sophisticated treatment than is usually accorded by modern philosophy. He shows us that substance dualism rests on more solid logical foundations than is usually acknowledged even if it smacks of being unscientific thanks to its infamous “interaction problem”.
From that point Feser looks at what has been offered as alternatives to Dualism, various materialisms (eliminative, functionalism, behaviorism, pure epiphenomenalism, causalism, reduction and supervenience) and quasi-materialisms (panpsychism, Russelian-monism, property dualism). All of this treatment constitutes the bulk of the book and as he covers each solution there emerges the best taxonomy of philosophies-of-mind I have yet seen. The modern emphasis on qualia is explored thoroughly but he argues that intentionality, even given the representational realism with which he begins, is more important, more central to mind and consciousness, than qualia.
In doing all of this Feser drives home the point that none of the alternatives is without serious metaphysical or epistemological problems. All of the quasi-materialisms, in fact, come up against the same interaction problem as substance dualism, and the others are either incoherent (two sorts of eliminativism), or simply do not get at two core problems: why do we experience anything at all and why does the subject that appears throughout all experience seem so obviously causally potent?
In the last chapter Feser asks if there is anything else that does address the core issue without having to invoke what ultimately comes down to God? His answer is Aristotle’s “Hylomorphic Dualism” (also championed by Thomas Aquinas though his variation relies directly on God). To explain consciousness, to get at its core and resolve the ever-present interaction problem, Feser says all we have to do is reject the contemporary physicalist insistence that material and efficient causes (two of Aristotle’s four leaving out formal and final cause) exhaust causality in the universe. This would be, to say the least, a big pill for 21st Century science, and most of philosophy, to swallow.
Further while Hylomorphic dualism might deal nicely with the epistemological issues Feser everywhere touches, it does no better than the quasi-materialisms concerning the metaphysical. Either the form of the human mind springs entirely from the arrangement and dynamics of physical particles, in which case we are back to reductive or supervenient materialism, or it does not. But if it does not, where does it come from? That physics cannot detect any teleology in the physical universe does not mean it isn’t there. It does mean that it has to come from somewhere other than physics and be prior to individual human minds. We are on the way back to God.
There is also a notable absence. Feser never mentions free will. A discussion might be beyond Feser’s scope in this book, but I’m surprised he did not at least note its obvious relation to intentionality. I will cover this and other implications in a blog commentary.