Raw Thought

by Aaron Swartz

A Very Speculative Theory of Free Will

Previously: How Quantum Mechanics is Compatible with Free Will

Attention conservation notice: I am well aware that this post will get me called all sorts of silly names and insults (Penrosian apparently the worst among them). For once, I am not going to respond. I just think the theory ought to be published and if you are not inclined to believe it, then feel free to ignore it.

The big mystery of the mind is reconciling two things: what we know about the physical structures of the brain and what we experience from day to day as conscious people. The first tells us that our brain is made up of a series of interconnected neurons which fire in response to certain inputs. The second tells us that people have subjective unified experiences and at least the appearance of free will. It seems hard to explain how the first can lead to the second, although they’re obviously connected somehow.

So, for example, if we’re looking at certain visual illusions, we can choose to see them one way or to see them another way. And obviously this choice has some impact on the rest of the brain, especially the part that processes vision. But nobody’s been able to find the place in the brain from which such choices originate.

I don’t know enough about the subject to vouch for it, but this article claims that neurons are small enough that we could see quantum effects in their high-level behavior:

The juncture between two neurons is called the synapse. Each of the perhaps 100 billion neurons in the brain is connected to about 1,000 other neurons. At the synapse, a firing neuron either passes a neurochemical signal to the next neuron, or it does not pass a signal, with the passing or not passing depending on the complex neurochemistry of the synapse. If, within a millisecond, a certain number of signals are passed on to a neuron, then that neuron will fire. Otherwise it will not fire. Thus what happens at the various synapses—signal passed on or not passed on—is the sole determinant of the firing pattern of the neurons in the brain. The synapses are the control points for our flow of thoughts.

The synaptic gap, the gap between one neuron and the next, is quite small, 3.5 nanometers, which is about 35 (hydrogen) atoms. The sizes of the adjacent parts of the synapse, where much of the neurochemistry goes on, are also small, on the order of 3,500 atoms wide. Now one of the peculiar effects of quantum mechanics is that if the volume where an atom might be located (the place where the wave function is non-zero) is initially small, it will spread out in time. One can use Heisenberg’s uncertainty principle to show that a calcium ion, for example, will spread out to the size of the synapses (not just the synaptic gap) in about .1 milliseconds (see 8 below). Neural processes in the brain occur on a time scale of a millisecond, ten times slower than the spread of a calcium ion over the whole synapse.

So here’s the proposal: a series of entangled quantum particles at the synaptic level allow for coordinated firing patterns which occur in response to choices by our conscious free will. Just as my previous post reconciled free will with statistical randomness, this would seem to reconcile free will with the neuroanatomy.

It still seems incredible that there is some high-level coordinated process with its fingers in the quantum effects of our synapses. But we know something incredible is going on because we have subjective experience. So this doesn’t seem like much of a stretch to me.

You should follow me on twitter here.

January 28, 2008


So you are saying our brain has a mechanism to choose which quantum state it’s in? That’s hard to believe. How could evolution (which acts on a non-quantum level) get a grasp on this process of jumping between parallel universes?

IMO there is no paradox of Free Will versus the mechanics of the brain. There is no Free Will. It’s an illusion.

posted by felix on January 28, 2008 #

  1. How could evolution discover consciousness? Same mystery.

  2. The parallel universes interpretation makes it easy: our consciousness only persists in the universe where the properties of the entanglement make sense. I don’t believe PU for a moment, though. (I’m a Bohmian myself.)

posted by Aaron Swartz on January 28, 2008 #

I don’t know what “unified experiences” means, and so I’m not sure I have them.

posted by Ben Donley on January 28, 2008 #

I’m not sure why you would object to being called “Penrosian.” From what I remember of The Emperor’s New Mind, your proposal here is exactly what he proposed 19 years ago. (Of course, I read it 18 years ago, so my memory may be flawed :)

posted by Jamie McCarthy on January 28, 2008 #

How could evolution discover consciousness?

It didn’t. Consciousness is an illusion. As is the passage of time, but that’s a separate argument :)

posted by felix on January 28, 2008 #

For once I’m on Aaron’s side:

For those of you call consciousness an illusion: An illusion is usually thought of as a misperception of reality by some observer. In other words, reality is in state X, while the observer believes that it is in state Y.

If consciousness is an illusion, who or where is the observer that is being fooled? If I’m fooled into thinking that I’m conscious, doesn’t that make me de facto conscious?

posted by Mark on January 28, 2008 #

“… a series of entangled quantum particles at the synaptic level …”

Sorry. I stopped taking the argument seriously at that point. That’s right up there with dilithium crystals depolarizing the transporter confinement beam causing a warp core breach. Red Alert!

posted by Seth Finkelstein on January 28, 2008 #

On the quantum thing.

There is no need to treat ions and nuclei quantum mechanically in any other model of macroscopic liquid collisions or electrochemistry. Classical theories of electrical conductivity (Debye Huckel theory for example) do perfectly well.

In a liquid each ion is surrounded by solvent molecules - the effective container size is much smaller, and therefore the timescales much shorter. But quantum treatment of nuclear motion is not needed at all.

In fact, in any chemical process where the atoms involved are bigger than hydrogen, quantum effects on nuclear motions are absolutely negligible. You do need to consider them to get realistic treatments of hydrogen bonding (a H atom bounces back and forth between two O atoms) but nothing bigger than that unless you are looking at very high resolution experiments.

The uncertainty principle calculation is a red herring. 1ms is a very very long time, and the Calcium ion will undergo many many collisions in that time, so any spreading of the wavepacket (implicitly, of an isolated ion) is swamped by the effect of collisions. It’s just not significant.

posted by tom s. on January 29, 2008 #

Quantum mechanics is the new souls.

posted by Seth Finkelstein on January 29, 2008 #

posted by haig Shahinian on January 29, 2008 #

Go read “On Intelligence” and realise you’re wrong.

posted by El Diablo Communista on January 29, 2008 #

I love On Intelligence but it has zero relevance.

posted by Aaron Swartz on January 29, 2008 #

I don’t know why some people can agree with applying occam’s razor to almost all other phenomenon we encounter, but then when it comes to their own ‘consciousness’ they suddenly decide to agree with elaborate theories of quantum entangled microtubules within our brain when it’s clearly the least probable theory. The brain is EXTREMELY complex as it is, with MASSIVE feedback throughout, and doesn’t require a leap to the QM hypothesis unless you need it for your own speculative reasons.

I once tried entertaining this quantum consciousness hypothesis with enthusiasm because if our consciousness is somehow caused by QM effects as Penrose suggests, then that opens up a window of possibility for elevating our ‘souls’ once again above just an evolved material machine and into the ‘spooky’ realm of of the quantum. I don’t think that way anymore but we don’t have a complete understanding of how brain creates mind yet, and so it still is a possibility, but a very very unlikely one. Why don’t you believe in intelligent design? It’s as likely as the QM consciousness hypothesis.

Consciousness, though I would hasten to call it an illusion, is what Minsky calls a suitcase word. A word which doesn’t have any specific definition and has come to represent one thing when in reality it is just an emergent epiphenomenon resulting from many different processes occurring at the same time.

What exactly does quantum entanglement add to the brain that could not otherwise be explained without it?

posted by haig Shahinian on January 29, 2008 #

Discussing free will without discussing identify (ie “what is free”) is like studying fish without any knowledge of water.

posted by Seth Russell on January 29, 2008 #

This idea in no way gets around the mind-body problem which has beset all dualist theories since Descartes i.e. how can there be any kind of causal contact between the mind (which must be non-physical to have free-will) and the brain (in your case entangled quantum particles at the synaptic level in Descartes the Pineal Gland)?

Penrose to his credit at least admitted that quantum theory was no use as random laws were just as useless as deterministic laws for free-will. What he argued therefore was that some as yet to be discovered property of quantum gravity would allow room for freewill. Francis Crick summarised this argument as follows “quantum gravity is mysterious, consciousness is mysterious so one might explain the other” Not very convincing is it?

But I think anyone who has read anything about this isssue would know most of this. Just for a change how about challenging the other side of the coin i.e. the assumption that we all experience free-will so that there is something that must be explained. Is that really your experience of everyday life? Presumably you work out, save money, have enriching hobbies, are always in a good mood with loved ones, have no bad habits etc etc? If not, why not?

Some people seem to think being an evolved, physical creature is a terrible fate but really most of the good things of life only make sense from this perspective. I love my little monkeys because I am a big monkey - it’s not rational or chosen. A free-will possessed, rational superbeing would be some kind of angel or monster.

posted by flex on January 29, 2008 #

And now I have started on the evryday experience of “having freewill” just use a little bit of introspection. An example I like to use is having a conversation. It is certainly not my experience that a little internal dialogue box pops up with options and I choose what to say, a freeflowing conversation happens too quick. I don’t know what I am going to say. In emergencies people often describe themselves as being surprised by what they did. We do not even have very good access to what our brain is doing never mind choose options. What we do have is language to report our internal states but this is at best partial.

posted by flex on January 29, 2008 #

“Consciousness is an illusion? How is that possible, since illusion presupposes consciousness?”

That’s a good point. Sounds a bit like: ‘I think therefore I am’. It depends on your definition of consciousness (and illusion).

What I meant to say is that consciousness has no physical reality. Our consciousness cannot affect physical reality. It is merely a by-product of physical processes.

I won’t deny that there is a phenomena of consciousness that we perceive. I just think it exists in some state other than physical reality. I imagine consciousness like an image on a TV screen. Physical Reality (the brain) is the phosphor and electronics of the TV. The image is generated by patterns in the TV’s physical state so it does exist in some way, but the image could never ‘decide’ to be a different image and rearrange the TV atoms. It’s a one-way street.

posted by felix on January 29, 2008 #

Why do you care about this so much?

I’ve seen so many very smart people pour so much energy and effort into arguing ad infinitum about the source of consciousness which, as far I can tell, nobody has any theories about how some might prove or disprove. I don’t know, and that’s fine, because I can’t see how either way would change any of my actions in the ways that have real effects on others.

posted by Benjamin Mako Hill on January 30, 2008 #

I tend to agree with what others have said about deploying Occam. You suggest our free will modifies firing patterns through a quantum-level mechanism. If our free will is a characteristic of brain activity, surely it’s more likely to influence directly, at an electro-chemical level?

I’m not sure the question of free will is a useful one anyhow, Occam again: is the existence of free will necessary for our perception of the thing we call free will? I doubt it, but that leads back into other questions of perception and consciousness.

I suspect there is a lot more can be usefully learned about consciousness, as some kind of emergent property at the interface between one complex system (the brain) and another (everything else).

I think I can summarise these points with the question: would a brain in a jar have free will?

posted by Danny on January 30, 2008 #

PS. Try substituting the word “magic” wherever you see the word “quantum”. Does that break anything?

posted by Danny on January 30, 2008 #

Random quantum effects isn’t free will. It’s random. I’m not sure how our neuro-chemistry can have an effect on exotic quantum effects. Perhaps some interpretation of collapsing the wave function through thinking chooses between alternate choices?

Good argument here:


posted by RXP on January 30, 2008 #

You’ve got the right idea, that it’s a matter of crazy huge and small scales, but you’ve got the wrong variables. Entangled quantum states is not a necessary construct. Way too small. Random thermal vibration of molecules, however, is a larger scale effect that can be modeled as a quantum effect (assuming our boy Gibbs has anything to do with it). I suppose you’d really need to understand how quantum mechanics gives rise to the statistical mechanical model we call thermal physics.

Once you understand that, you need 1) evolutionary time 2) mesoscale time 3) size of the brain 4) number of synapses in a brain (trillions) 5) number of neurons in a brain (billions) 6) various derivative things, like synapses per neuron, specialization of sets, local and disseminated sets, etc. 7) fraction of brain not consumed with reptilian tasks 8) Number of and types of machines in neurons: R ribosomes, P protein systems, S second-messenger systems (and S’ and S” and S”’, etc), nuclear signaling systems, SNRPs, etc. (probably measuring in the thousands).

So you’ve got thousands to millions of transistor-level machines inside each of billions of cells interacting in trillions-raised-to-the-trillions of combinations. Plus lots of specialization in diffuse and local patterns. Floating in a electrodynamic soup. You don’t need entangled quantum states. The state of that system is thoroughly complex enough at the molecular/chemical/thermal-physics/statistical-mechanics level.

Some of these neurons are just wet half-adders. Some are these sensual, diffuse distributed things that monitor crazy stuff, like system temperature.

I think Jeff Hawkins has the right idea. The reptilian brain is sort of a motherboard type of thing and the cortex is a sort of large storage system, which can also be used for virtualization of various additional machines. I think these virtual machines would be the classical brain areas, like Wernicke’s area, Broca’s area, that sort of thing.

posted by Niels Olson on January 30, 2008 #

You know, on the virtual machine thing … I’m sure you’ve seen the old grids of magnetic balls suspending at the nodes of a wire grid, the first addressable storage? All those cortical neurons are members of similar, highly defined, highly systematic, structures. They don’t have names, as I recall, but you could think of them sort of like disk sectors. But they’re arranged in columns. If you unwrap the wrinkled cortex and lay it out like a sheet, and inject a single cortical neuron with some dye, you’ll see it that dye diffuse to involve a small column (and I think it’s actually a hollow column, a tube, if you well) of neurons near by. One can imagine the white matter axons underlying these columns could be going to columns and the signal on the axon is designed to query that column and the column has developed through experience in such a way to respond to the stimulus by retransmitting another pattern, perhaps back the way it came, perhaps down another axon, or series of axons. And once a certain series of patterns is replicated and reinforced enough, a stimulus goes to some other extra-cortical area, like the limbic system where you might feel some fear or longing, or from the motor cortex do the basal ganglia and out to the extra-pyramidal systems (extra-pyramidal = (but not ==) extra-cortical: cortical neurons are generally pyramidal in shape).

posted by Niels Olson on January 30, 2008 #

Mako++ :)

posted by Jacob Rus on January 31, 2008 #

((my english is not good enough for this - please excuse.))

it does not seem too amazing that the idea of free will can be reconciled with neuroanatomy - especially by investigating the process: starting after the intention behind, no matter from which perspective, quantum or magic. ;-) Neither one - free or determined thought - would be contradictionary to the neuronal transmission, I promise ;-)

and the other way round: nothing we will explore on a material level will object free will. insofar quantums are the “best” focus.;-) a huge amount of liberty is still far away from freedom.

Randomness „possibly seen as maximum of freedom“ may at any level be the result of/our word for explaining/observing without knowing enough, which again is very probable. Personally i dislike the word random, as it seems more like our observation of „the most effective evolvement system“ to me: maximum freedom, but within a system : no goal + evolvement energy + the system or ist initiation. No goal is as close as possible to „free will“: we can choose (the goal)– within the system. And now again, maximum evolvement would actually be what i would invent if i was almighty and bored/courious ;-) (we are certainly not (yet) the observers of the whole illusion - but that is no argument against illusion.) personally i would not call it an illusion – i would call it a possible, relational and restricted experience ☺ (@being lucky: this is truly a question in strong relation to ones thoughts, which are related to chemical processes too: while thoughts can go “down” in a spiral to depression or be depressive by birth reasons– they can be enabled to be cured chemically, because of the material relation – how great. So in general: you will always and everywhere find the relation between biology, chemistry, physics – material. Thats the relation, the restriction-and though possible „freedom“ of our consciousness ;-) consciousness as result of „evolution“ (again i prefer evolvement) is still a creative power - so it seems likely that there is a creative power behind evolution - as it is ongoing creation („random“ or determined) – but it simply does not necessarily assume a TARGETED creator. so THIS seems to be the question and the answer to my little brain: if there is/would be a goal - it is/would be determinism, if not - it is, restricted by birth,challenge/reaction/power,time and death: something like free will :-) (not too free, uh? :-)) (nothing seems to be targeted, actually, except evolvement to higher level itself as purpose: which again, to be most effective, demands the illusion of free will for creative consciousness, which again allows to avoid too - so this IS free will (including insecure outcome) then. (not too free again, as any choice has consequences – and most humans are aware of this – without knowing the outcome for sure, they do know an individually different amount of „unified relations possibilities“ restricted by fear of anything – but „free will“) so i do personally replace „free will“ with „free choice and will based on values“ if there is a creative power behind evolution we simply can’t answer the question of free will, because it is the wrong question, admittedly an important one though - it is a question of what dimension we discuss. which, in the end means that there is no free will, as free will would mean: at any dimension and free of restrictions. but it is quite reconciling that there is free will within the finite-dimensional experience of time: the subjective one.

posted by sleepy aber in schreiblaune on January 31, 2008 #

If a pseudo random number generator is not compatible with your definition of free will I do not understand how a (real) random number generator can make it any better. How does the “free” come into play if our mind draws its inputs for decisions from a stream of random numbers?

posted by Conny on January 31, 2008 #

You should read Johnjoe McFadden’s Quantum Evolution.


posted by flippy on January 31, 2008 #

How dumb is Swartz?

“So here’s the proposal: a series of entangled quantum particles at the synaptic level allow for coordinated firing patterns which occur in response to choices by our conscious free will”

What exactly has this to do with free will? You conveniently forgot to mention were free will comes from in the first place.

So here is my proposal: a series of entangled Micky Mice at the synaptic level allow for coordinated firing patterns that occur in response to choices by our conscious free will.

P.S. Sorry, I could not resist. It is not to be taken personally. But you should hold you own theories against the same standards you do with others.

posted by Conny on February 1, 2008 #

If you assume that ‘you’ are defined, then it seems to me that, according to Hawking’s forthcomming artilce, your choices could actually determine their causes.


posted by Seth Russell on February 4, 2008 #

This one tortured me from the age of 15 or so (whenever I saw a Horizon documentary on AI, Searle etc) to midway through university, when I gave up on the dream. This was a huge shakeup for my worldview, and was greatly influenced by hearing Susan Blackmore talk to the philosophy dept here (1992/3 i guess). She had spent years passionately chasing evidence for the paranormal, before regretfully - and bravely - coming to the conclusion that it just wasn’t there. Until I heard her speak I was chasing the same trails, and looking for a story about consciousness via quantum wierdness was (for me) a part of that. Yeah I’d call them Penrosian ideas btw.

Subsequently I’ve come to terms with being composed of inanimate matter, and with my thinking, feeling and remembering (avoiding nouns here helps; Dennett got that from Ryle fwiw) being grounded in fairly ordinary chemistry. I used to find that picture of the world somehow horrible and cold; now I find it strangely beautiful. Rather than being made of ‘mere matter’, I get to think how amazing it is that the only difference between me and my ‘raw ingredients’ is the way I’m arranged. It’s left me with an almost pantheistic outlook…

posted by Dan Brickley on April 1, 2008 #

I do not understand the problem. And this solution with quantum mechanics certainly does not solve anything.

Let’s just assume something: One really smart mind finds out the answer to the question whether there is free will. Now he tells people “Hey, the solution is, there is no free will, its all deterministic”. What would happen? Nothing. Nothing would change - the world would run as it was. So lets assume something else: He finds out that we do have free will. Wow, everyone likes to hear that somehow, but what would actually change? Nothing. Again no one would do anything different just because he knows he has free will. Ok - so for me the conclusion is: There is no difference. Its both the same - free will or not free will, the problem does not exist.

Oh yeah - there is this third option - the guy finds out “well, its all quantum stuff”. Well first of all - I don’t get why anyone would conclude that this “reconciles free will”. By definition it means everything is random. No will at all and no determination. (and I’ve read your other article about it, I think there you pretty much agree at the end). Now what does that solve? Nothing at all.

I think the question you ask is the wrong one. We do have to first find the correct question - then we can try to find the right answer.

posted by Thomas Schmall on October 7, 2009 #

Let’s just assume something: One really smart mind finds out the answer to the question whether there is free will. Now he tells people “Hey, the solution is, there is no free will, its all deterministic”. What would happen? Nothing.

I don’t think that’s quite fair. Imagine someone discovers one day that the Eiffel Tower isn’t connected to the ground. In one sense, this wouldn’t change much — people would still go up in the Eiffel Tower, it would still look nice in photographs, etc. But it would be very fascinating to learn how it managed to stay in one place without being connected to the ground and also why everyone thought it was connected to the ground for so many years.

posted by Aaron Swartz on October 11, 2009 #

You can also send comments by email.

Email (only used for direct replies)
Comments may be edited for length and content.

Powered by theinfo.org.