Material Property Dualism
Material Property Dualism
(MPD) predicts there is something material in our brain which has the subjective qualities, such as redness, we experience. While Functional Property Dualism
predicts the same experience will "arize" from "anything functionally equivalent" from neurons to silicone this theory predicts that without the right stuff, in the right state, a redness experience will not be possible. A quality like redness could be a quality of anything from quantum effects to some form of electromagnetic phenomenon, as being predicted by various sub camps theories.
David Chalmers authored the paper "Consciousness and its Place in Nature"
where he nicely classifies various camps about consciousness. This Material Property Dualism camp is similar to the theories he classified as "Type F Monist"
MPD predicts qualities like a redness quale are the most absolutely fundamental properties in existence. Most people accept that the causal physical properties we can detect with our senses and scientific instruments are a fundamental part of nature. MPD predicts this is correct, but it also predicts that we must additionally realize that all we know of these causal physical properties, is abstracted information about their behavior we interpret from our senses. Because of the quale interpretation problem we are blind to anything other than this abstracted information about these behaviors. Our senses can't know any qualitative (in the quale sense) information of any natural stuff they are detecting. The world in our head image by Steven Lehar is meant to portray this in a vivid schematic way.
What is redness a quality of?
The Idealized Effing Theory World
predicts it is something like glutamate that has a redness property, which our brain uses to 'paint' our phenomenal knowledge of a strawberry with. When we think of a strawberry out there we are perceiving, we imagine it as having a redness property. We tend to think of this redness quality as causing the surface of the strawberry to reflect 650 NM light. But of course, this would be a mistaken way to think about it, since if we add a red vs green inverter anywhere in the perception process, we will then represent the strawberry with knowledge that is made of greenness. Obviously, the greenness has nothing to do with the surface of the strawberry, and is only a concept in our mind we are using to think about the strawberry with.
But what, then is redness a quality of, and how is the best way to think about it? Material Property Dualism predicts the best way to think about a redness quality, is just the way we intuitively think of it as a property of the strawberry, causing 650 NM light to be reflected. It's just that redness is not a quality of the strawberry, it is a quality of something our brain is using as our knowledge of such. The causal properties of the neural correlates we already know about are what the qualities are causing, instead of the light being reflected off of the surface of the strawberry, because of its redness quality.
Obviously, 650 NM light doesn't reflect off of the strawberry, because we think of it as having a redness quality. But something, casual, is going on in our mind, because it does have a redness quality we can experience. We only say, yes, that is our redness, precisely because of its fundamental phenomenal quality. But, obviously, if we look at such brain stuff with abstracted observation systems that suffer from the quale interpretation problem, we will be completely missing a large part of why the particular behaviors we are observing, are behaving the way they are.
In the Idealized Effing Theory World
, imagine if we set up an experiment where we repeatedly replaced different neurotransmitters representing someone's knowledge of a red point on the surface of a strawberry. The person would repeatedly say that is not my redness, until you used what really did have the redness property - glutamate. Of course, that is how it would be experienced. If you looked at this same system with an observation method that sufferers from the quale interpretation problem, since you would be completely blind to any of the fundamental phenomenal properties, the system would just look like a very good detector of glutamate. And you'd be able to simulate such abstracted knowledge in any old abstract computer system. But, you'd be missing quite a bit about why it was working the way it was working, and why it was capable of only saying "yes, that is my redness" with nothing but glutamate.
We think of bits, in a computer, the same way we think of redness on the surface of a strawberry. We imagine little ones and zeros laid out on a spinning disk the head is reading. But, just like the the fact that there is no redness on the surface of the strawberry, there are no ones or zeros on a spinning disk. The "bits" or abstracted information are all in our head. Just like you can invert the red/green signal in our perception process, you could add a bit inverter on the USB output of a hard disk. Even though the hard disk hasn't changed at all, other than this inverter on the output, suddenly all the ones are now zeros and visa versa.
In our brain, these ones and zeros can be strung together to make something like 0xFF0000, and we can think of this as 'red', 'stop' or even as representation of reality on which a higher level simulated computer is built and operating. But, again, none of these higher levels exist in the computer, they only exist in our head, as different ways to think about the fundamental natures of the stuff we've organized independent of whatever might be interpreted as representing such. No matter what level you think about it in any such abstracted way, it has no effect on the fundamental causal properties which we are interpreting at the fundamental basement, or any other, level. Other than our abstracted interpretations about any of the representations, it's all just the physical stuff, at the basement level, being interpreted at whatever level we decide in our heads.
Possibly starting with Alan Turing, and as our digital computers become ever more capable, there has been a growing in popularity idea that 'information' is more fundamental than any of these fundamental natures. One version of this kind of thinking is captured in the idea of "digital physics"
which is making predictions like you can "get it from bit"
. But, again, the 'it' you get from any higher level simulated 'bit', doesn't really exist. 'bits' are just an abstracted way to think of the fundamental natures we've organized to behave the way we want them to, so we can think of them or interpret them as this 'it' we got from the 'bit'.
It seems to us to be sloppy thinking when people like Daniel Dennett make a claim like we don't have qualia 'it just seems like we do'. This is because we rigorously define 'seem' to be having knowledge that doesn't accurately represent its referent'. Given that definition the mistake becomes clear. Perhaps people that think this way are thinking of some other definition of what it means "to seem"?
Similarly, when intelligent people make a claim like we can get "it from bit" they are making yet another sloppy thinking mistake. Perhaps you can define 'information' and 'bits' in a different way, such that it is possible to base a theory of fundamental physics on such ideas - but you certainly can't use the common sense definition of an abstracted 'bit' as we've rigorously defined it here: "A 'bit' of information is only some way to interpret whatever is representing it, in a particular way, and has nothing to do with the representations fundamental natures which are being interpreted as such."