What it seems philosophy of mind is trying to do is create one-to-one match-ups between what exists according to commonsense and what our present physical and neuropsychological theories can say about the mind.
The folk philosophy of mind theory is supposed to work sort of like a function in mathematics: “For every input there is exactly and only one output.”
Except in philosophy of mind we’re not that certain there are one-to-one match-ups like that. So it’s more like quantum indeterminacy, or should be.
Many philosophers still believe some sort of one-to-one rule applies to our concepts about the mind. That implicit thesis is defended by the majority of philosophy professors and academics in the consciousness studies.
We try to find a nice spot in our theory about the mind for all sorts of things we think must exist. Consciousness must exist, or an explanation of it must, so we have to be able to place that in our theory. That is given.
We also think beliefs and desires exist, so we must find a place for that too. That there is something called “first person experience” that must also have a counterpart in our theory as well. These are the things the folk thesis wants to salvage.
But identity theory (making those match-ups) has been called into question before. And we changed our theories because of it. Science use to think there was a fluid substance that held heat inside bodies, kind of like water in a sponge.
But we got rid of that when we decided heat was the rapid movement of trillions of jostling molecules that actually did the heating. We also thought, even further back, that demonic forces could possess people and turn them into witches. That, however, has been taken over by modern psychology, and they no longer explain mental conditions in demonic or Biblical terms.
In each case, something was eliminated. It seemed unlikely that we would arrive at a nice one-to-one match-up between the concepts of folk psychology and the concepts of theoretical neuropsychology.
That intertheoretic match-up is required if we think all the commonsense things can be reduced to neuropsychological things. But some things are just not reducible. You can’t reduce the heat substance to the theory that says the heat substance doesn’t exist. You have to eliminate that idea of the heat substance.
As I see it, the one-to-one match-ups will not be found in the philosophy of mind either, and our commonsense psychological framework will not have an intertheoretic reduction, because our commonsense psychological framework is a false and misleading conception of the causes of human behavior and the nature of cognitive reality.