I’ve written before in reply to materialist Jerry Coyne’s assertion that free will is an illusion. The gist of Coyne’s denial, shared by others of course, is that nature is deterministic and that the mind is a wholly material process, yoked to the laws of physics and to an organism’s evolutionary history. Thus, our choices are completely determined and free will is an illusion.
I’ve already pointed out his error on the question of determinism. Today I’ll focus on his error regarding the materiality/immateriality of the will.
We have a variety of mental capabilities (or powers). We have sensation and perception, memory, imagination, intellect, and will. Philosophers since Aristotle have noted that intellect and will differ qualitatively from other mental powers. The difference is in the substrate on which intellect and will act, on the one hand, and sensation, perception, memory, imagination, and desire act, on the other.
The substrates are particulars and universals. Particulars are specific things in nature that are presented to the mind by our senses — an apple sitting on my desk, or a wedding ring on a finger, or a friend walking into an office. Universals, on the other hand, are concepts that do not have physical instantiation in nature. The beauty of the red color of an apple, love for a spouse symbolized by a wedding ring, musings about the nature of humanity occasioned by a friend in an office are all examples of universals. Goodness, truth, and justice are universals.
Our senses present us with particulars. We see and smell the apple, we feel a ring on a finger, we hear a friend. Particulars grasped through sensation and perception, as well as imagination and memory, have an obvious composition with matter. We use our eyes to see, our skin to feel, our ears to hear. There are well-defined regions in the brain whose activity seems to be necessary for the exercise of these sense-perception powers by which we grasp particulars. In that sense, the grasp of particulars is material, or at least depends on matter in a necessary way.
The same is not true of intellect and will. There is not the same intimate link between intellect and will with matter that there is between perception and imagination, etc., and matter. Through our intellect we grasp and comprehend universals, not particulars, and our will carries out decisions made by our intellect. For example, we see (perceive) a picture of Nelson Mandela (particular), we ponder (intellect) injustice (universal) done to political prisoners, and we donate (will) to Amnesty International.
So the fundamental question is this: Are intellect and will material powers, like sensation and perception are material powers?
The answer is no. Intellect and will are immaterial powers, and obviously so. Here’s why.
Let us imagine, as a counterfactual, that the intellect is a material power of the mind. As such, the judgment that a course of action is good, which is the basis on which an act of the will would be done, would entail "Good" having a material representation in the brain. But how exactly could Good be represented in the brain? The concept of Good is certainly not a particular thing — a Good apple, or a Good car — that might have some sort of material manifestation in the brain. Good is a universal, not a particular. In fact the judgment that a particular thing is Good presupposes a concept of Good, so it couldn’t explain the concept of Good. Good, again, is a universal, not a particular.
So how could a universal concept such as Good be manifested materially in the brain?
The only answer possible from the materialist perspective, it would seem, is that the concept of Good must be an engram, coded in some fashion in the brain. Perhaps Good is a particular assembly of proteins, or dendrites, or a specific electrochemical gradient in a specific location in the brain.
But the materialist is not home yet. Because in order for Good to be an engram in the brain, the Good engram must be coded in some fashion. How could Good be coded? A clump of protein of a specific shape two mm from the tip of the left hippocampus? Obviously there’s nothing that actually means Good about that particular protein in that particular location — one engram would be as Good as another — so we would require another engram to decode the hippocampal engram for Good, so it would mean Good, and not just be a clump of protein. Yet that engram for the code for the engram of Good would itself have to have some representation of Good in order for it to mean that it signifies the code for the Good engram, which would require another engram for the engram for the Good engram, ad nauseam.
In short, any engram in the brain that coded for Good would presuppose the concept of Good in order to establish the code for Good. So Good, from a materialist perspective on the mind, must be an infinite regress of Good engrams. Engrams all the way down, so to speak, which of course is no engrams at all.
The engram theory of intellect and will presupposes that which it purports to explain.
Concepts such as Good can’t be material manifestations in the brain. The intellectual grasp of concepts and acts of will based on universals are inherently immaterial.
Of course, specific particulars that we judge to be Good (a good apple, etc.) may have material manifestations of some sort in the brain (even that is problematic, at least from our modern metaphysical perspective), but concepts involving universals cannot have any material manifestation whatsoever in the brain. A concept is an immaterial thing. And of course the normal operation of intellect and will may be influenced by other psychological powers — such as perception, memory, and imagination — that are linked to matter in some fashion.
Good may seem different after a few beers, for sure. The intellect is influenced by matter (in that case, EtOH), but the intellect, which grasps concepts, and the will, which acts on concepts, are inherently immaterial. And promissory materialism is of no avail here — the inevitable materialist segue to "It may make no sense now, but give scientists time…" The immaterial nature of the intellect and will is not demonstrated by experiment, but by logic. It simply makes no sense to say that intellect and will are material, unless one accepts infinite regress as a valid hypothesis. (Given the materialist proclivity to deny the relevance of all philosophy, which would include logic, infinite regress may well become the materialists’ new tactic.)
Free will is the exercise of an immaterial power of the mind, and is not constrained by deterministic processes in nature, even if nature is deterministic, which it isn’t. Coyne’s argument against libertarian free will fails on that basis.