Friday, December 11, 2020

Does quantum mechanics rescue free will?

 

Philip Goff has challenged Kevin Mitchell’s interesting supposition that the indeterminacy of quantum physics creates some “causal slack” within which free will can operate. In essence, Kevin suggests (as I understand it) that quantum effects create a huge number of possible outcomes of any sufficiently complex scenario (like human decision-making), among which higher-level mechanisms of organismic agency can act to select one.

Philip responds that this won’t do the trick, because even though quantum mechanics can’t pronounce on which outcome will be observed for a quantum process with several possible outcomes, it does pronounce on the probabilities. He gives the example of his decision to water his dragon tree Susan (excellent name):

“Let’s say the Born rule determines that there’s a 90% chance my particles will be located in the way they would be if I watered Susan and a 10% chance they’ll be located in the way that corresponds to not watering Susan (obviously this is a ludicrously over-simplistic example, but it serves to make the point). Now imagine someone duplicated me a million times and waited to see what those million physical duplicates would decide to do. The physics tells us that approximately 900,000 of the duplicates will water Susan and approximately 100,000 of them will not. If we ran the experiment many times, each time creating a million more duplicates and waiting for them to decide, the physics tells us we would get roughly the same frequencies each time. But if what happens is totally up to each duplicate – in the radical incompatibilist sense – then there ought to be no such predictable frequency.”

It’s a good point, insofar as it needs an answer. But I think one exists: specifically, Philip’s scenario doesn’t really have any meaning. In this respect, it suffers from the same defect that applies to all attempts to reduce questions of human behaviour (such as those that invoke “free will”, a historically unfortunate term that deserves to have scare quotes imposed on it) to microphysics. The example Philip chooses is not “ludicrously over-simplistic” but in fact ill-defined and indeterminate. I don’t believe we could ever determine what is the configuration of Philip’s particles that predisposes him to water Susan. It’s not a question of this being just very, very difficult to ascertain; rather, I don’t see how such a configuration can be defined at the quantum level. We would presumably need to exclude all configurations that lead to other outcomes entirely – but how? What are the quantum variables that correspond to <watering Susan> or <not watering Susan (but otherwise doing everything else the same, so not cutting Susan in half either)>? What counts as “watering Susan”? Does a little water count? Is watering Susan before lunch the same as watering Susan after? This is not a simple binary issue that can be assigned Born probabilities – and neither can I see how any other human decision-making process is. (“Oh come on: what about ‘Either I press a button or I don’t’”? But no, that's not the issue as far as free will is concerned – it’s ‘Either I decide of my own volition to press the button, and I do it, and the botton works’ or not. And what then is the quantum criterion for ‘of my own volition’? How do we know it was that? What if I was bribed to do it?... and so on.)

Obviously such scenarios could go on ad infinitum, and the reason is that quantum mechanics is the wrong level of theoretical description for a problem like this. We simply don’t know what the right variables are: where the joints should be carved in an astronomically complex wavefunction for many particles that correspond to the macroscopic descriptions. And again, I don’t think this is (as physicists often insist) just a problem of lack of computational power; it’s simply a question of trying to apply a scientific theory in a regime where it isn’t appropriate. The proper descriptors of whether Philip waters Susan are macroscopic ones, and likewise the determinants of whether he does so. At the quantum scale they don’t just get intractably hard to discern, but in fact vanish, because one is no longer speaking at the right causal level of description.

This is, in fact, the same reason why Schrödinger’s cat is such an unhelpful metaphor. No one has ever given the vaguest hint at what the wavefunctions of a live and dead cat look like, and I would argue that is because “live” and “dead” can’t be expressed in quantum-mechanical terms: they are not well-defined quantum states.

I don’t necessarily argue that this rescues Kevin’s idea that quantum indeterminacy creates space for free will. I’m agnostic about that, because I don’t think what we generally mean by free will (which we might better call volitional behaviour) has any meaning at the quantum level, and vice versa. It’s best, I think, to explain phenomena at the conceptual/theoretical level appropriate to it. As Phil Anderson said years ago, it’s wrong to imagine that just because there’s reducibility of physical phenomena, this implies a reductive hierarchy of causation.

You’ll see very soon in Physics World why I’m thinking about this…

4 comments:

Disagreeable Me said...

I don't see that it's necessary for it to be possible to determine what micro-physical configurations of particles would result in Philip watering Susan for Philip's point to stand.

You point out that, strictly speaking, watering or not watering is not binary, but that there are a range of intermediate outcomes. And yet presumably when Philip actually does water Susan, it's always pretty clear whether he has or has not. He is not in the habit of offering Susan just a few drops or deciding to cut Susan in half. In 99.999% of the branches of the wavefunction, there is no difficulty in identifying whether Susan has been watered or not. If you really do need a binary, then you can imagine embedding a moisture detector in Susan's pot. If the detector goes off, 99% of the time it will mean that Philip has watered Susan. If it does not, then 99% of the time it will mean that Philip has not. The question then is whether Philip has any free will in influencing the probability of whether it goes off or not. The fact that freak events can also occur doesn't matter very much because their probability is small. The outcome is influenced by Philip's decision far more than by any other factor.

I guess this just turns the watering Susan analogy into the pressing the button analogy. But I'm not sure I understand your objection here. Yes, he could be held at gunpoint and ordered to water Susan, but that's not the scenario Philip is considering. He is wondering in his daily life whether there is room for indeterminist free will to influence his decisions to water or not water. Coercion doesn't enter into it.

Michael Patriciaa said...

This year 2020 has been so blissful to me for God has given me a reason to live happily again after been heart broken for 6 years when my husband neglected me and went back to he's mistress. I suffered and went through all types of emotional tortures for i couldn't get any help to get my man back not until i was refereed to Dr. Iyaya by my co-worker who gave me her full assurance about him that he can be of help to me. I got in touch with Dr. Iyaya and i hearken to his words and followed the instructions given to me by him. Could you believe that my husband got back home within 48hours as said by him and today, my marriage is restored & i'm so thankful, appreciative & grateful to God for using Dr. Iyaya to get my man back after 9 months of broken marriage. Is there anyone out there who needs to get back to he's or her lover back or needs any help of any kind? Then, i suggest that you get in touch with Dr. Iyaya now through his Email: doctoriyaya@gmail.com Call WhatsApp +2347032756397 for more information, visit his website you may found your solution there www.https://dr-iyaya-herbal-remedy.webnode.com God bless you sir.

GET THE BEST PENIS ENLARGEMENT PRODUCT said...

I want to share this wonderful testimony to the Good people all over the world on how I was able to Enlarge my Penis by Dr. Aziba. I was living a shameful life from my young age, just last month as I was browsing on the internet about Penis size  and Enlargement Products, I saw a testimony of a Man called Tim James testifying of how he was able to get his penis Enlarged by Dr. Aziba and I decided to also Email Dr. Aziba for my small penis size and he quickly respond to me and gave me the normal instructions which i did and then he shipped the product to me here in the united state which i received in just 3 working days and today i am very happy because i started seeing positive changes in my penis size in just 7 days of use.  Dr Aziba herbal product is the best recommended for you and to whom ever suffering from this shame or having any other diseases as well should Contact this great herbal doctor via his Email : Priestazibasolutioncenter@gmail.com and WhatsApp Him on +2348100368288






I want to share this wonderful testimony to the Good people all over the world on how I was able to Enlarge my Penis by Dr. Aziba. I was living a shameful life from my young age, just last month as I was browsing on the internet about Penis size  and Enlargement Products, I saw a testimony of a Man called Tim James testifying of how he was able to get his penis Enlarged by Dr. Aziba and I decided to also Email Dr. Aziba for my small penis size and he quickly respond to me and gave me the normal instructions which i did and then he shipped the product to me here in the united state which i received in just 3 working days and today i am very happy because i started seeing positive changes in my penis size in just 7 days of use.  Dr Aziba herbal product is the best recommended for you and to whom ever suffering from this shame or having any other diseases as well should Contact this great herbal doctor via his Email : Priestazibasolutioncenter@gmail.com and WhatsApp Him on +2348100368288

nancy said...

i was cured of herpes simplex virus 1 & 2 by a great herbal doctor called Dr sayo with the use of pure natural roots and herbs. it is still like a dream to me. There is no word suitable enough to qualify your significant in my life dear doctor. he can also cure any kind of diseases/virus and illness You can contact him via email: (sayoherbalhealer@gmail.com) or whatsapp him +2349012175679 you can also visit his FB page: https://www.facebook.com/Sayo-Herbal-Healer-100145798345000/    and take a good look on his website: http://sayoherbalhealinghome.com/     My little way to appreciate you doctor is to advertise your great work and that is what i am doing now