I'm not relying on supervenience to prove that physicalism is true. I don't claim that physicalism is definitely true, only that it may well be. If I were to say I was a physicalist I would merely be adopting physicalism as a working assumption. Up until now you have been saying even this position would be untenable because physicalism must be either logically wrong or absurd.
It's fine for doing empirical science. The problems are philosophical ones.
Supervenience may be "compatible with" those positions but as long as it does not require them then there is no reason why physicalists should have a problem.
So long as they are not using supervenience as a definition of physicalism this is OK.
I know you don't believe supervenience physicalism to be true, but you are now admiting that it is coherent, aren't you?
The theory is coherent, in so much as it claims that minds supervene on matter. But the "physicalism" bit is a problem. It's not a problem because supervenience isn't true, but because anything which claims to be physicalism but cannot reduce all mental terms to physical terms is incoherent. By admitting a definition of "mind", at all, it sets up the same incoherence that all the other non-eliminative forms of materialism suffer from. In this case, it will be logically impossible to explain
exactly how mind supervenes on brains.
You are admiting that you can neither disprove it or dismiss it as absurd.
No. I think I can prove you can never explain how/why mind supervenes on matter. There are two issues about
being which are linked, but which physicalism doesn't recognise as linked. One of those issue is the existence of why the universe exists at all. This is just an unanswerable for physicalism - the big bang just happened and that is it. This doesn't prove Goddidit, but it leaves a key issue about Being unresolved and largely forgotten/dismissed. But it sets up a problem for physicalism - a logical problem from which there is no escape. It leaves something unaccounted for. Let's call it
anomaly 1. The consequences only surfaces when the physicalist next encounters the issue of Being and that is when he tries to explain how minds arise from matter. It turns out he can't do it, which is why he has to turn to eliminativism. This problem, which the physicalists have spent this entire thread trying to claim doesn't exist, is the result of having forgotten anomaly 1. It is
anomaly -1. The reason they can't fix the system is because the system can only be fixed by recognising that anomaly 1 and anomaly -1 cancel each other out. To return to your question, supervenience works as a solution because anomaly -1 has now been "sectioned off" by using the word "supervenes" instead of the word "are". By removing the claim about Being ("are") it has sectioned off both both anomalies at the same time. By not making an explicit claim of physicalism, it avoids the assertion that sets up anomaly 1. And by not claiming that "minds ARE brain processes" it partitions off anomaly -1 to be dealt with at a later time. Thus it finds a way to get rid of both halves of the anomaly about Being without linking them together. BUT - as soon as you call it "supervenience physicalism" you have re-introduced anomaly 1 again. This is not an immediate problem at the other end, because anomaly -1 remains sectioned off by the word "supervenience". However, this means that the supervenience physicalist can never find a way to explain how minds supervene on matter. But the only way you can really justify calling it physicalism is if this explanation is at least theoretically possible. It isn't, so supervenience physicalism is also false. However, it is a vast impovement on the alternative versions of physicalism. It doesn't make any meaningless claims revolving around abuses of the verb "to be".
