A criticism of supervenience-based physicalism

pftest

I am under the impression that people generally believe supervenience to be a physicalist view on consciousness, whereas i think it is the opposite. In the wikipedia link below, there are 4 criticisms of supervenience-based physicalism. The one i'm talking about here isnt mentioned, so i want to put it up for scrutiny.

Supervenience:
http://en.wikipedia.org/wiki/Supervenience
http://plato.stanford.edu/entries/supervenience/


In the wikipedia link, on the right side you can see an image that says:

I think this image illustrates where it goes wrong. It starts right at the top where it says "levels of existence". I think this should be "levels of description". The molecule-level is a higher level description than the atom-level. These descriptions are conceptualisations, done by human minds. Physically, there is only one level of existence, the lowest one, and all the other levels can be said to consist of that. Cells consist of molecules, molecules consist of atoms, atoms consist of elementary particles. So they are " = " relationships. A human mind can introduce an arbitrary number of new levels of description, but this has no physical consequence as the elementary particles are still just elementary particles.

When it is said that mind supervenes on brain, it translates to mind = brain, meaning: mind = a group elementary particles, meaning: a group of elementary particles = mind. That means mind has been around as long as those particles have, not to mention the universal nature of the properties of elementary particles. The loophole to avoid this was the view that mind somehow exists at a higher level, but my argument above is that such higher levels are purely conceptual, so they depend on a mind to exist and cannot have come about without mind.

Ferris_bg

I think your example illustrates emergence. And supervenience does not always entail emergence.

Supervenience condition: Two systems engaged in the same physical activity will produce identical mentality (if they produce any at all).

And, yes, I completely agree that emergence is a psychological property.

Weak emergence is a type of emergence in which the emergent property is reducible to its individual constituents. This is opposed to strong emergence, in which the emergent property is irreducible to its individual constituents.

Emergence: Properties of a complex physical system are emergent just in case they are neither (i) properties had by any parts of the system taken in isolation nor (ii) resultant of a mere summation of properties of parts of the system.

As, stated by Kim:

[Ontological physicalism] All that exists in the spacetime world are the basic particles recognized in physics and their aggregates.

[Property emergence] When aggregates of material particles attain an appropriate level of structural complexity ("relatedness"), genuinely novel properties emerge to characterize these structured systems.

[The irreducibility of the emergents] Emergent properties are irreducible to, and unpredictable from, the lower-level phenomena from which they emerge.

Maui

An example of strong emergence irreducible to anything is the ability of humans to make predictions(not counting the ridiculous stance that the Big Bang could be an explanation because of determinism/causality)

pftest

To me they seem like the same thing, just worded differently.

One could say molecules emerge from atoms.
Or that molecules supervene on atoms.

pftest

But we dont know if mind emerged, so that isnt really a valid example. In order to find out if emergence or supervenience are natural explanations of mind, an example of emergence/supervenience occuring in the natural world is required.

Maui

I didn't say 'mind' and lots of novel traits and behavior can in principle emerge from purely physical interactions(the brain can act in novel ways even if minds didn't exist).

apeiron

What this way of looking at it misses is that these levels of existence are interactions across different spatiotemporal scale. And that makes all the difference to the argument.

So it seems just commonsense that a particular arrangement of brain particles always will yield the exact same higher level mental state. Lower level state B picks out higher level state A.

But the material description picks out a global state of organisation only at that one particular instant of time. And if that global level is "doing its own thing" causally - if it is not just a deterministic clockwork - then state B does not equal state A for more than that fleeting instant.

What you are claiming would only hold true for a supervenient relation plus strong determinism - the first to tie things down in the spatial domain (the realm of "definite existence"), the second as an additional claimed constraint to nail things down in the temporal domain (the realm of global dynamics or the potential for change).

The original meaning of supervenience was an attempt to go beyond simple-minded determinism and talk about holism or organic unity. So the stress was on the asymmetric nature of the relationship. Lower level states could pick out a higher level state at an instant, but not for all time. Higher level states had their own stuff going on that lower level description just could not see. And this higher level stuff - the essence of the global level - was thus multi-realisable. No reason why other lower level states could not pick it out as well.

If you use an example like the living things~social groups one mentioned here, you can see it is a local~global spatiotemporal relationship. Incan society supervenes on Incan individuals. There is some general cultural understanding and framework that develops over many generations that comes to define Incan - not just as an anthopologist's conceptual label but as an actual fact of the world. There is an Incan-making machinery that exists. Humans born at that place and time will be made into Incans with great inevitability (though not, of course, complete deterministic certainty).

And also, all the Inca that exist at some instant in history would seem to equate to "Incan society". All that they are, all that they do, sums back up to the collective whole - at least for that moment. And so you can imagine twin universes with the exact same lower level state (the same collection of individuals in the same environmental circumstances) and the same higher level state (Incan society) would have to exist in both worlds. (But not for all time, as left to their own devices, those two worlds will start to diverge - come back 500 years later and "Incan" would look unpredictably different, no matter how indiscernible the two initial states).

The problem with debates about consciousness is that consciousness is framed by most people in an a-temporal fashion. Consciousness just is a state of awareness at some instant. And so if conciousness is going to have any "higher level stuff going on" - such as downward causality or freewill control - then this has to happen instantaneously as well. Which of course is logically incoherent. And leads immediately to all the difficulties people have.

Q_Goest

Hi pftest,
I think this is basically a misunderstanding of what supervenience means.
You say the elementary particles have been around [presumably since some beginning], not to mention the universal nature of those particles, so I believe your argument is that since these particles have been around all that time, minds should have been around all that time and since minds obviously haven't been around all that time, minds can't be physical. Is that correct?

You could say the same for aircraft though, or buildings or anything. The particles that make up those things have been around so buildings and aircraft must have been around all that time.

Here's where I think the confusion is. Note that when we say something is supervenient on something else, we're not talking about it simply existing or being composed of something else. Supervenience is a property relationship. There has to be a property which is a function of its physical basis in order to use the term 'supervenience'. We say that some given property A supervenes on some organization of matter only if a change to that property A requires a change to the organization of the matter of which it's composed. For example, the hardness of a diamond is supervenient on the way the particles are assembled, so to change the hardness of the diamond, you have to change the way the particles are assembled. Supervenience isn't a 'made up of' relationship, it is a relationship that picks out a given property and says that particular property can't change without a change to its base. Given that supervenience picks out property relationships which are a function of something's physical configuration, we can't say there should be a property we call mental states without a physical configuration we call a brain. We have to have the physical configuration first, before we can say the property exists. Then we can say the property supervenes on its physical basis if and only if that property requires a change to that physical basis in order for the property to change.

Pythagorean

Supervenience is not an equivalence statement. Supervenience is a unidirectional statement; one supervenes on the other: mental states supervene on physical states.

In the other direction, several different physical states can map to a single mental state; this is called "degeneracy" and it is exhibited (at least functionally) in neural system. See Eve Marder's work:

Multiple models to capture the variability in biological neurons and networks
Eve Marder & Adam L Taylor
Nature Neuroscience 14, 133–138 (2011) doi:10.1038/nn.2735

http://www.nature.com/neuro/journal/...l/nn.2735.html

pftest

It would help if there was a clear example of physical supervenience, preferably a very simple system which can be understood quickly. "Incan society" is not really a suited example because it includes conscious beings and so cannot be understood in mere physical terms. What i suspect is going on here, is that the human mind makes an abstraction of the myriad of incan individuals, and then calls this mental abstraction "incan society". So like i said in my first post, it is a higher level description, not a higher level of physical existence.

pftest

Predicting is a mental activity, like dreaming, thinking, doing math, etc. We have no idea if it emerged.

pftest

Actually im not saying minds havent been around all that time, im saying that supervenience entails that they have been.

Yes, but the thing is that "aircraft" is a higher level description, while physically it is a collection of particles at a spatiotemporal position. We can say that those particles have been around in different spatiotemporal positions. If we want to talk about the immediate postbigbang situation in terms of higher level descriptions, then we might say that "diluted" or "distorted" aircraft were around at that time. In the end "aircraft" is just an arbitrary label. If the aircraft loses one screw, we arbitrarily still call it an aircraft. If its particles are distorted to a postbigbang mess, we arbitrarily might also still call it an aircraft.

Im glad you bring up an exampler. Lets focus on the hardness of a diamond. I believe this to be basically nothing more than an arrangement of particles and forces. To a human hand, a diamond may feel hard, it may feel smooth, other materials may feel squishy, wet, etc., but physically it all boils down to the arrangement of particles and forces. So it is an "=" relationship.

Remember in your previous post to me you mentioned your "pet-rock"? Im still wondering why you mention the pet rock, as opposed to an ordinary rock.

pftest

Im looking for an example of purely physical supervenience, which can demonstrate that supervenience is an actual physical type of relationship. That would demonstrate that "mind supervenes on brain" is a physicalist statement. Both examples of supervenience you give here are examples of mind supervening on brain. So they are disqualified as examples, because it would be begging the question: "mind can physically supervene on brain, because physical supervenience is possible, as is demonstrated by mind supervening on brain".

Ferris_bg

pftest, no one knows if mind supervene on brain, that's just the physicalist position. So when one attempts to defend it, one assumes this as true and goes on from there. I can say mind supervene on legs then you can say "yeah, but people with no legs still have minds". Then I can say prove it to me. And you can't, because we still don't have a working model about what consciousness is. And while there are plenty of people trying to find a way to study it objectively, there are also plenty of people seeking through logic on what this phenomenon may depend. That's why there are many philosophers who work as part of neuroscience projects and consciousness is the holy grail of science.

Q_Goest

Hi pftest,
Ok, thanks for clarifying.

Agreed. However, the objectively observable properties that an aircraft might have do not exist in this "diluted" or "distorted" aircraft. That's why I don't like the "Levels of Existence" chart given by Wikipedia. It's confusing. For supervenience, we have to pick out some physical property, not simply the 'level of existence'. The only way to make the Wikipedia chart make sense is to explain it this way:
1. Social groups have properties that are dependent on living individuals such that those properties can't change without a change to the living individuals. (can't think of a good example here)
2. Living individuals have properties that are dependent on cells such that those properties can't change without a change to the cells. (ex: The strength of a muscle is a function of the cells out of which its composed. Not a good example.)
etc...

The chart is poorly thought through and not a very instructive example of supervenience. I've never seen any kind of chart like that nor references to levels of existence as they show in any of the philosophical literature. I'd recommend throwing the chart away and focusing on the definitions of supervenience provided, especially the one provided by Standford EP. I'd be glad to provide other definitions by Kim for example, who goes through it in some detail. Let me know if you'd like to see those.

The pet rock was a poor example so I'll take that one back. Regarding the diamond, let's say the diamond came from the carbon in the ground which came from the decay of a dinosaur. The carbon in the dinosaur decayed after it died, was covered by miles of rock, compressed and heated so that the carbon atoms rearranged themselves into a diamond, and that diamond was eventually discovered. The carbon atoms existed the entire time, but the property of hardness that we attribute to the diamond didn't come about till it was formed. So here's a property that didn't exist previously. It only came into existence after the right conditions stripped away the bonds of other atoms that made up the dinosaur and stuck the carbon back together under great heat and pressure. Similarly, the particles that are in my brain have been around for a very long time, but they haven't been arranged into the present configuration till very recently, so the properties they have today (both physical and mental) can differ from properties they had before I was born.

It's worth noting that the properties of the diamond are objectively verifiable properties. We can verify the hardness of a diamond through interactions with other physical things such as a hardness testing device. So in the case of the dinosaur, we can verify there was no property of the dinosaur that had the hardness that the diamond has. We can objectively verify there was no measurable property of hardness so we can create a supervenience statement, "The diamond has properties that are dependent on its carbon atoms such that the hardness can't change without a change to the (arrangement of the) carbon atoms."

The same can be said of mental states. Mental states are dependent on the physical states such that the mental states can't change without a change to the physical states.

Note that the 4 arguments against supervenience-based formulations of physicalism given by Wikipedia all hinge on the subjectivity of mental states. These arguments all rely on the fact that there is no objectively observable property. None of the arguments would suggest there are changes to objectively observable physical properties given the changes the authors have proposed.

Maui

I am not sure what your point is, but I also find it hard to believe that decoherence creates reality independent of minds.

pftest

My point is that it is not a physicalist position at all. Saying that the mind supervenes on the brain is like saying that mind is a dream had by the brain. Both dreaming and supervening are mental activities, so both claims simply translate to "mind is done by mind". Supervenience is meaningless in physical terms.

I know we dont have a working model of consciousness and i know philosophers cannot prove their metaphysical positions, however, supervenience is said to occur even outside of brains and minds, for example in diamonds.