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Professor Jerry Coyne has recently written a highly critical post entitled, Ken Miller, confused, finds free will in quantum mechanics, in which he attacks Professor Miller’s invocation of quantum physics to rescue free will. In a recent Youtube video, made on March 23 of this year at the New York Academy of Sciences, and featuring theologians John Haught and Nancey Murphy, Professor Miller elaborated his views:
At its finest level, matter has an inherent unpredictability, which certainly doesn’t explain free will, but certainly gives the lie to the notion that any inherent mechanical system is ultimately predictable. And I don’t think we are predictable: I think that capacity to make choices is ultimately wired into the circuity of our brain, and that’s how we become autonomous beings; that’s how we make judgments; that’s how we decide to seek the truth and how we make moral decisions. (Emphases mine – VJT.)
Quantum unpredictability: necessary but not sufficient for free will
Professor Coyne was incredulous that Miller could make such a claim:
What? Quantum mechanics to the rescue! … The obvious problem is that Miller equates unpredictability with free will. I’m willing to grant that perhaps events on the quantum level would lead to two universes, started off at the exact same physical configuration, winding up at different states in the future. What neither I nor any other competent thinker is willing to concede is that quantum unpredictability has anything to do with “free will”. A “decision” does not become free if it’s merely the result of the unpredictable movement of an electron somewhere in our brain. How can anyone believe that stuff?
I have to say that I was mystified by Professor Coyne’s failure to understand the simple point being made here by Professor Ken Miller. Professor Miller nowhere equated unpredictability with free will; indeed, he explicitly stated that unpredictability doesn’t explain free will. What he said was that unpredictability is a necessary but not sufficient condition for the existence of free will. No philosopher or scientist claims that a decision becomes free simply by virtue of being unpredictable; hence when Professor Coyne remarks that “A ‘decision’ does not become free if it’s merely the result of the unpredictable movement of an electron somewhere in our brain,” he is merely attacking a straw man.
Professor Coyne will probably want to know precisely how quantum physics makes free will possible, if the former is a necessary but not a sufficient condition for the latter. In my post, How is libertarian free will possible? (July 14, 2011), I provided a detailed model which attempted to address this very question. I discuss this model below. Professor Coyne is welcome to critique my model if he so wishes.
There is one thing that Professor Coyne gets absolutely right, however: genuine free will is incompatible with determinism. He and Professor Miller agree on this point, against philosophical compatibilists (such as Professor Daniel Dennett) who argue that our actions can be completely determined and yet fully free. I critiqued Dennett’s view in my post, Battle of the two Elizabeths: are free will and physical determinism compatible? (14 August 2011).
Is emergentist materialism sufficient for genuine freedom?
In the Youtube video I linked to above, Professor Miller went on to say that our capacity to make choices is wired into our brains. Evidently he is an emergentist materialist:
We are collections of not just the molecules that make us up, but also the cells that make up our bodies. These collections have emergent properties – and what I mean by emergent properties is: the 100 trillion cells that make up a human being together are capable of doing things that no-one in their right mind would ever look at a single cell and say that cell is eventually able to do. I’ve never looked at a cell under an electron microscope and said, “You know, that’s the cell that can compose a symphony,” or “That’s the cell that can hit a baseball,” or do just about anything else. And I think out of these emerging properties comes not just the ability to make moral decisions, but the ability to basically, as an organism, made up of all these different parts, to try to ask questions like, “What is the truth, and why should we seek it?” (Emphases mine – VJT.)
On this point, I would have to respectfully disagree with Professor Miller: I would say that our non-deterministic brains allow us to make free choices, but that brains themselves are incapable of freely choosing anything. In my post, Why I think the interaction problem is real (July 13, 2011), I explained why higher-level emergent properties of the brain cannot account for freedom:
It might seem tempting to say that higher-level bodily actions can bring about lower-level bodily actions. That’s fine, so far as it goes. However, if we are to have genuine freedom, then these higher-level bodily actions must be just as ontologically fundamental as the lower-level bodily actions that they determine. For if these higher-level actions are determined by lower-level bodily actions occurring at a previous time, then we are back at square one again: we are once more the prisoners of our body chemistry, and bottom-up causation rules.
If you’re going to argue that higher-level emergent processes occurring in the brain can explain human freedom, then you’ll have to argue that these processes were not determined from below at a previous date. But can brain processes be free?
Arguments against mechanistic materialism
In my post, I then provided links to some short, highly readable philosophical posts (see here, here, here, here and here) demonstrating that a purely bodily action could not possibly qualify as a free choice. (See here for a more serious paper by the late Professor James Ross.) However, I realize that Professor Coyne is distrustful of philosophical reasoning, as he considers it to be based on unverifiable armchair argumentation, so today I’ll try a different tack. Instead, I’d like to suggest that Professor Coyne have a look at a non-technical mathematical paper by the Oxford mathematician J. R. Lucas, which was read to the Turing Conference at Brighton on April 6th, 1990. It’s an argument based on Godel’s theorem, which aims to show that mechanism is false. Lucas originally developed the argument in an article entitled, Minds, Machines and Godel (Philosophy, 36, 1961, pp.112-127). In his subsequent 1990 paper, Lucas elaborated his argument and defended it against some common criticisms.
I can move the neurons in my brain
There are some philosophical dualists (e.g. Professor Edward Feser) who have argued (see here) that the “interaction problem” is a pseudo-problem. In my post, Why I think the interaction problem is real, I argued that interaction between persons and their brains really occurs. I went on to defend the view that persons (not brains) make choices, and that it is simply “a basic fact of human nature that whenever I perform the non-bodily action of deciding to move my right arm, region ‘X’ of the motor homunculus in my brain (i.e. the area in my brain which governs right arm movements) is activated, and whenever I decide to move my right leg instead, region ‘Y’ of the motor homunculus in my brain (which governs right leg movements) is activated.” This was a deliberate oversimplification: I further acknowledged that “the mechanics of voluntary movement [described above] is grossly oversimplified, as it overlooks such things as feedback, forward modeling, fine motor-tuning and proprioception.” In the same post, I also criticized the view (commonly known as Cartesian dualism) that “that mind and body are two things, and that the former interacts with the latter in a purely mechanical fashion – as if the mind were like a ‘spiritual billiard ball’ that could somehow set ‘physical billiard balls’ (i.e. neurons in the brain) in motion.”
How is quantum physics related to free will?
I wrote about the relation of quantum physics to free will in my post, How is libertarian free will possible? (July 14, 2011), in which I provided a detailed model of how a non-bodily act of top-down causation transforms a non-deterministic brain into the executor of a free choice made by a person. Here is the relevant excerpt from my post:
Reasoning is an immaterial activity. This means that reasoning doesn’t happen anywhere – certainly not in some spooky Cartesian soul hovering 10 centimeters above my head. It has no location. Ditto for choice. However, choices have to be somehow realized on a physical level, otherwise they would have no impact on the world. The soul doesn’t push neurons, as Eccles appears to think; instead, it selects from one of a large number of quantum possibilities thrown up at some micro level of the brain (Doyle’s micro mind). This doesn’t violate quantum randomness, because a selection can be non-random at the macro level, but random at the micro level. The following two rows of digits will serve to illustrate my point.
1 0 0 0 1 1 1 1 0 0 0 1 0 1 0 0 1 1
0 0 1 0 0 0 0 1 1 0 1 1 0 1 1 1 0 1The above two rows of digits were created by a random number generator. Now suppose I impose the macro requirement: keep the columns whose sum equals 1, and discard the rest. I now have:
1 0 1 1 1 0 0 0 0 0 1
0 1 0 0 0 1 1 0 1 1 0Each row is still random, but I have imposed a non-random macro-level constraint. That’s how my will works when I make a choice.
For Aristotelian-Thomists, a human being is not two things – a soul and a body – but one being, capable of two radically different kinds of acts – material acts (which other animals are also capable of) and formal, immaterial actions, such as acts of choice and deliberation. In practical situations, immaterial acts of choice are realized as a selection from one of a large number of randomly generated possible pathways.
On a neural level, what probably happens when an agent decides to raise his/her arm is this: the arm goes through a large number of micro-level muscular movements (tiny twitches) which are randomly generated at the quantum level. The agent tries these out over a very short interval of time (a fraction of a second) before selecting the one which feels right – namely, the one which matches the agent’s desire to raise his/her arm. This selection continues during the time interval over which the agent raises his/her arm. The wrong (randomly generated quantum-level) micro-movements are continually filtered out by the agent.
Facts are stubborn things. If the facts suggest that materialism is wrong, then it is time to look for a better model. In this post, I have attempted to describe a top-down, “person-body” dualist model which addresses the nuts and bolts questions relating to free will, and which explains how quantum indeterminacy makes it realizable within an organism with a human body.