Should I continue to?
— Philosophim
No. I think not. — I like sushi
Well too bad, I'm going to respect you still for making a good follow up post.
:)
I think there might have been a misunderstanding between us. If you recall, you wanted me to explore an IF scenario, and perhaps between me saying, "Ok, lets assume X is true" and my own viewpoints, what was thinking in your scenario vs my viewpoints may have gotten mixed up.
So, supervenience. To my understanding of the word, it is a non-causal dependency relationship. I think you misunderstood, or I did not communicate clearly enough, what was supervenient. I did not mean to imply that mental properties were supervenient to the brain. I meant that mental properties were supervenient to physical properties. In other words, subjective experience is still a physical property at the end of the day, not a brand new separate substance of existence. I say this not because I don't think that there can't exist a non-physical substance, its that I see no evidence that it could be some type of non-physical substance. Its why I've been asking for people to define exactly what they mean by 'non-physical' and present an example of something 'non-physical' existing that wasn't merely a miscategorization of something physical.
To repeat, I don't say mental properties are supervenient on the brain, but physical processes of the brain. I don't think supervenience works very well in regards to the brain because as I noted, physical processes affect other physical processes. Meaning, that IF subjective experience is a physical process, it impacts other physical processes in the brain. We see this in studies as well. The placebo affect. Creating positive subjective experiences can affect the brain's objective state in a positive manner. Supervenience as a description here does not work because these are causal dependency relationships.
If you hold to there being a difference between Properties of items under discussion AND hold that there is no Substance Dualism then it does not logically follow that you can have this both ways due to the condition of Supervenience — I like sushi
As you can see, I hold no substance dualism, there can still be a difference between subjective experience and objective observation, but we do not have supervenience between the brain's objective actions and subjective physical experiences of the brain are two separate physical processes that affect each other.
The only reason why someone can even propose that the subjective experience of the brain is 'non-physical' as something plausible, is because we cannot objectively identify subjective experience. We cannot 'be' some other thing besides ourselves. Because we cannot currently do this (and maybe never will be able to), this results in the hard problem. How do we figure out the link between our objective knowledge of the brain and the subjective experience of that brain? Currently, we can't.
Even if you sat down and mapped out your specific brain to your subjective experiences, how do you mark that down objectively? "I see green. But you might also feel happy. And might also be thinking of what you're having for dinner." You can describe all of that, but how can anyone else objectively understand that? What do you mean, "You see green?" Is it the same green that I see. What are the dimensions of green. How do you chart mental space in dimensions? What is the experience of being happy for you vs any other person? How do I objectively write down and measure a 'feeling'? Where in your mental space are you seeing green vs thinking about what you're having for dinner tonight?
In other words, we have no objective means of describing and recording subjective experience. The subjective experience of one individual is only inferred by another, never objectively known. As such, we can't even correctly map our own personal subjective experience in a way that accurately captures our own subjective experience, let alone others. That is why its impossible to link the objective mind to subjective experience in specific detail. We lack the measuring tools, concepts, and capabilities to do so.
This has caused some to think, "Does that mean that subjective experience is something non-physical?" A great idea to explore. Whenever humanity is faced with limits, we can still use logic based on what we know to come to at least some reasonable conclusions. Quantum mechanics is completely based around this idea. It is currently impossible for us to measure a quantum state without our very measuring tools affecting the outcome of the quantum state. Despite this, we've made a logical scientific theory that is often used successfully in the real world.
The brain is the same thing. We can approach the brain and ask if subjective experience is non-physical. Of course, we first have to define what physical is, then define what non-physical would be. Then in tests, we would look for results that either fit in with physical results, or outside of expected results. What neuroscience and pharmacology have consistently resulted in over decades is that subjective experience is a physical process. It follows and behaves physical laws. Its tied to a physical location in space. Physical drugs and manipulation of the brain result in rather consistent outcomes like physical laws entail. Subjective experiences affect the brain just like causal interactions between physical things do.
For subjective experience, we would need examples of outcomes which are necessarily non-physical. Thoughts not tied to the brain for example. One way causality. Physical affects on the brain, the location of subjective experience, having consistently unpredictable outcomes on subjective experience.
That, to my knowledge, simply hasn't been the results we've seen. Time and time again, despite not being able to specifically record and detail subjective experience objectively, the outcomes in which subjective experience are broadly generated implies a physical reality, not some other non-physical substance.
So, this is why I'm not a physicalist. I do not assert that everything is physical. I simply assert that subjective experience can be reasonably concluded as physical because there is no indication of subjective experience being non-physical in decades of exploring the brain. Could it be that tomorrow we do find something non-physical about subjective experience? Sure, anything is possible. But asserting that subjective experience must be non-physical does not align with our current understanding of science. It is the far less reasonable conclusion to make, and to my understanding held together by a wish and a hope that our inability to objectively record subjective experience allows that something non-physical could be hiding there. The problem of course with dreams like this, is without any evidence its simply as likely to be physical. With the fact that there is a mountain of evidence that subjective experience is physical, and almost none that it is non-physical, the rational position is to assume at this point that subjective experience is physical.
What does that make me? Just a person who believes the most rational conclusion we can make with the current scientific evidence that we have now, is that subjective experience is physical. No claims in how exactly the brain maps to it. No claims that the hard problem doesn't exist. No claims that we can objectively map subjective experience down. Just noting that when we define physical vs non-physical and look at the tests over the years, the evidence for subjective experience being physical is overwhelming while the evidence for it being non-physical is almost null.