Free will is not an illusion, except that it is, says philosopher

I find attempts to reconcile free will and determinism like these to be interesting, but not convincing. I believe in free will over determinism and reject the notion that they are compatible. Regular readers will be aware that this is something I only ever try and rationalise, not investigate from first principles. The main problem is that defining "free will" is bloody hard, and not something I feel I can write down on a whim. At some point I will try and explain what I actually mean by free will, but for the moment, articles like this are helpful for me only in discovering what it is I already believe. And to anyone who says, "but that's not very scientific of you, Rhys !" I will cheerfully smile back in agreement.

Anyway, on to the article. There are some aspects I agree with :

I am quite happy to concede that free will requires intentional agency, alternative possibilities among which we can choose, and causation of our actions by our mental states. I think the mistake in the standard arguments against free will lies in a failure to distinguish between different levels of description. If we are searching for free will at the fundamental physical level, we are simply searching in the wrong place.

I agree that agency and intent are real, and cannot be due to the action of atoms bashing about. The action of choosing is a non-physical thing. But I disagree with the idea that it's simply an emergent property, as the author appears to suggest :

The neuroscientific skeptic is absolutely right that, at the fundamental physical level, there is no such thing as intentional goal-directed agency. The mistake is to claim that there is no such thing at all. Intentional agency is an emergent higher-level property, but it is no less real for that. Whenever our best scientific explanations of a particular phenomenon commit us to postulating certain entities or properties, then it is very good scientific practice to treat those postulated entities or properties as genuinely real. We observe patterns and regularities in our social and human environment, and the best way to make sense of those patterns and regularities is by assigning intentional agency to the people involved.

Meteorologists are interested in higher-level patterns and regularities. In fact, the very notion of weather is a higher-level notion. At the level of individual air molecules, there is no such thing as weather. Perhaps the system at that very fine-grained level of description would indeed behave deterministically according to classical physical laws, but as you move to a more macroscopic description, you abstract away from this microphysical detail. That is not driven by ignorance on our part, but by the explanatory need to focus on the most salient regularities.

But isn't "weather" just a label for system of air molecules ? It certainly makes some kind of sense to think of the larger properties of a weather system being responsible for the behaviour of a storm or a whirlwind, rather than having describe how every single friggin' molecule interacts. And those larger properties are indeed emergent : you cannot describe the air pressure of a single molecule, or the humidity of a single water atom - those properties only exist in bulk. So the idea that the actions of individual atoms is governed by the emergent properties in a top-down approach is undeniably useful.

But I don't think this invalidates the bottom-up nature of the emergent properties in the first place. Suppose, during a storm, two air molecules collide and bounce apart. During that interaction, their trajectories should be determined only by their speed and their interaction with each other. The overall properties of the storm don't directly control their behaviour : the properties of the storm only emerge from the collective behaviour of countless air molecules. That, to me, is what emergence actually is. The storm itself is just a label for this vast collective behaviour; though it may be impossibly complex to actually calculate the behaviour of the storm by monitoring the actions of every molecule, in principle there's no reason this couldn't be done (neglecting quantum effects for the moment).

If you were modelling a weather system particle by particle, you would give each particle its various properties and find that humidity and pressure and so on emerge from the individual elements. At no point would you never need to specify the global parameters, because they result implicitly and inevitably from the local ones. Conversely, you couldn't use the global parameters to directly specify the local ones.

When we talk about "humidity", we use a label of a physically meaningful state. It's helpful to use this in simulations because it's usually not possible to model every particle. "Humidity" is a just a word, a way to describe how many water molecules are present per unit volume : what it refers to is physically real, but humidity itself is in a sense not real - there are no humidity particles to be found anywhere. Emergent properties are simply descriptions : they are convenient and useful, because they let us approximate enormous numbers of particles with much smaller quantities, but they are not physical and don't fundamentally drive anything.

We can attach probabilities to different scenarios, but it’s not the case that the weather state at the present time fully determines the weather state in a few days’ time. Multiple different trajectories are entirely possible. Likewise, to describe the complete state of a human agent, we do not describe the full microphysical state of every elementary particle in the brain and body. That would be the wrong level of description. If you ask psychologists, cognitive scientists, and economists, they will give you different theories of how human choice-making works. But they all treat human beings as agents who are faced with choices between different options, so all these theories assume alternative possibilities.

So far as I can tell, the author here means for us to discard the prospect of true randomness (i.e. from quantum effects or whatever) for the sake of argument. In that case, I think the weather state at any given time does determine its future evolution (barring external influences like a change in solar radiation). I cannot see how an emergent collective property - a description - could possibly be said to control the behaviour of individual atoms. The motion of a single atom is influenced only by the actions of those it directly interacts with, not the emergent property itself.

In that sense, I see the definition of free will here as missing the point. If it's something that simply arises from the collective action of smaller processes, if it's just a label for a vastly complex set of interactions because we can't chart them all, if, in effect, it's simply way of saying, "this is all just too complex for us to understand", then it's robbed of force. I don't see how if free will is merely a label for a complex set of deterministic processes then it can be anything other than an illusion.

If free will as I understand it truly exists, then it ought to be capable of driving the movements of individual atoms just as much as it is moving arms and legs. For instance, it should be possible to see a flow of electrons develop in the nervous system that simply cannot be explained by tracking the behaviour of every individual particle involved.

This is an uncomfortable notion, to be sure, but I don't see the alternatives as being any more agreeable.

Let’s say I now form the intention to move my arm to lift this glass to drink some water. What should we cite as the cause of this particular arm movement? A leading philosopher raised an important challenge against mental causation, the so-called causal exclusion argument. If you consider a particular effect and you’ve found a cause that fully accounts for that effect, you should not simultaneously postulate yet another distinct cause for the same effect. That would be an act of causal overattribution. You can fully account for the action by reference to the physical state of my brain, so there is no reason to postulate yet another cause—namely, a distinct mental cause. 

My response, which Peter Menzies and I developed, is that if we accept the interventionist theory of causation, the causal exclusion argument does not generally hold. For any given system, the most systematic causal relations may not involve the lowest-level variables, but could involve higher-level variables, or there might be systematic causal relations at both levels.

But which process fundamentally drives the other ? It's easy to see, in principle, how the action of one particle can influence another, and another and another, and so on until the collective action causes me to go and get a glass of water or torture a duck or whatever. In contrast, I cannot see how my desire (to torture ducks or drink water) itself can then be said to drive the actions of my individual atoms - at least not in sense that's meant here. Rather, what I mean by free will is something I daresay is more mystical : the idea that my choices have little or nothing to do with how the electrons in my brain move, but instead that my will (whatever that is) does not merely ultimately describe a flow of electrons but actually controls them.

I haven't got the foggiest idea how this works, or how compatible it is with the scientific world view. I'm simply saying that's my view of free will regardless of what anyone else thinks. And don't worry, I have no secret desire to torture ducks.

Yes, Determinists, There Is Free Will - Issue 72: Quandary - Nautilus

It's not just in politics where otherwise smart people consistently talk past one another. People debating whether humans have free will also have this tendency. Neuroscientist and free-will skeptic Sam Harris has dueled philosopher and free-will defender Daniel Dennett for years and once invited him onto his podcast with the express purpose of finally having a meeting of minds.