A criticism of supervenience-based physicalism

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.

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

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

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.

Let me try to formulate your claim better as premises and a conclusion:

P1: mind supervenes on brain is like mind is a dream by brain
P2: dreaming and supervening are mental activities
C: supervenience is not a physicalist position

The fundamental problem here is that this is not a real argument, it is a non-sequitor. It does not follow that supervenience is not a physicalist position from your premises.

Furthermore, I don't think that P2 is correct if you're using standard accepted definitions and you would have to justify P1. As Q_Goest said, supevenience is a property relationship. Supervenience is not a mental activity or an activity at all. One cannot go around "supervening" in an event-based manner. Abstract objects, called sets, are what supervene. Set theory is a branch of mathematics, but the basic concepts of set theory are relatively simple and available on wikipedia. This is also why A=B is not true:

To the physicalist, the set A (mental events) are contained in the set B (physical matter and interactions) and, in most cases, B is considered to be the universal set.

You said strong emergence is possible and gave human predictions as an example. My response was that predicting is a mental activity, so that example of disqualified since it would be begging the question: "mind can emerge from brain, because emergence is possible, as is demonstrated by mind emerging from brain".

To show that mind can emerge from brain, a different example of emergence is required.

It does follow because saying that mind supervenes or mind dreams is equivalent to saying mind does what mind does, "mind = mind". Physicalism is supposed to be "mind = physical".

Ive bolded the important part: abstract objects. All abstractions are conceptual, existing only in the mind. So yes you are exactly right to say that abstract objects are what supervene.

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.

Your first paragraph still has some problems with it. You're taking the phrase "what mind does" and using it two different ways but saying they're the same because they share syntax.

To your second paragraph, that is not automatically incompatible with physicalism. You first have to determine to what degree a physicalist position relies on scientific realism. A physicalist may full well know the concepts hes using are a result of how he and his culture have imposed boundaries on observations and still hold a physicalist position.

It is observed that something that resembles a mind can emerge from brains. Observations count as evidence.

But this is not valid reasoning. A physicalist believes all that exists is the physical, so it's dubious that a hardcore physicalist would ever use a loaded word like 'mind'. And no, mind is a particular state, not an object, so it cannot be physical in the traditional sense of the word. And yes, i agree, if mind is not physical but is yet supervenient on physical brains, physicalism would be in trouble exlaining the interaction between the physical and the non-physical.

Im not sure i follow, but if you mean that i use the word "mind" in different ways, it may be so. This is because i consider mind a container term that encompasses a lot of different abilities: seeing, thinking, abstracting, predicting, emotions, etc. (and im adding supervenience to the list in this topic) Whenever one of those things is taking place, it implies mind is present. So te position that mind (which includes all of those things) supervenes on brain, is like the position that minds dream.

What would such a position be like?

What observation?

All we know is that minds exist in brains. It doesnt follow that it emerged in them. Electrons exist in skyscrapers, but they did not emerge in them.

In your previous post you said that we can only give examples of observed behaviour, and that is exactly what im looking for: observed cases of supervenience that occur in physical systems. I dont know any such examples. The same goes for strong emergence. Ive looked at the physicalist position for a while, and i havent found any phenomena in the natural world that behave the way consciousness behaves according to physicalists. Simply put, that makes the physicalist position unnatural by the very definition of that word. That is why such examples are important. If someone can show that supervenience happens in rocks, it makes the idea of supervenience in brains natural.

Now you appear to be starting your assumption with your conclusion ("I'm adding supervenience to the list"). Supervenience isn't an event "taking place". It's a declaration about how to sets relate

Pessimstic induction

Actually, everything that you observe and consider physical can be said to be strongly emergent. It has been 80 years of constant attempts by the scientific community to find and establish the physical basis of physical reality. They failed. Instead, they find more evidence of inconsistencies with physicalism. In a sense, everything from an electron detections to atoms and cats and dogs, can be said to be strongly emergent from more basic principles.

The opposite proposition - that brains could have emerged from minds will hardly be tolerated here(unless there is some science behind such a hypothesis, not just valid inferences stemming from inconsistencies of physicalism). From what i've seen so far here and in the literature, most physicists, even the most brilliant ones, will back off defending physicalism past a certain point if you push them too hard. So your doubts aren't completely unwarranted either.

Anyway, there is a very solid connection established scientifically between minds and brains(this is completely the opposite point of view):

Phantoms in the brain by Ramachandran(part 1):

http://www.youtube.com/watch?v=sq6u4XVrr58

However, as far as i know about neuroscience, the connection between mind and brain is one of correlation. To illustrate: there is correlation between the distortion of spacetime and the mass of a planet earth. Such a correlation doesnt mean that spacetime originates and is limited to planet earth.