paper, dont read, boring. technically, this should count as about 4 blog posts professor g ;)

This paper will focus on the shortcomings of three very popular objections to physicalism, functionalism, and the type identity theory (or Australian materialism): The Mary’s Room thought experiment, the zombie objection, and the inverted spectrum argument. These objections are united in their attempt to cast doubt upon physicalism by their central claim that mental states involve qualia, or the non-physical “properties of the beholder”. How pain feels, what red looks like, and how honey tastes are all examples of qualia. Within this paper I will attempt to show that qualia can in fact be explained physically, and that these three arguments do not reveal any contradiction within a materialist view of the mind.

I will now briefly define the central claims of the type identity theory and functionalism. The type identity theorist holds that consciousness is a brain process (in the same way that lightning is a motion of electric charges), and each type of mental state is a type of brain state. Functionalists on the other hand hold that every mental state is a “functional state of a whole organism”, and that each mental state is a disposition to behave in a certain way, and to have other mental states. Functionalism is said to be substrate neutral because it claims that mental states can be realized by multiple entities other than the human brain, as long as they are functionally equivalent (such as a sufficiently advanced computer).

The Mary’s Room thought experiment was originally proposed against the type identity theory and physicalism in general. It goes something like this: Mary has had a microchip placed in her brain at birth that prevents her from seeing the color red. She grows up to be a brilliant scientist and learns all there is to know about the color red. When the microchip is finally removed, it seems that Mary obviously learns something new when she first sees something red. Proponents of this argument claim that because a person can learn all the physical facts about color and still know nothing of what it looks like, there must be something non physical going on every time we see color. In other words, because physical facts are not sufficient to provide this subjective experience, the mind or part of the mind is non-physical.

Although it may be true that there is a difference between knowing what the color red is and knowing what it looks like, our ability to sense qualitatively the color red can well be explained by the physical structure of our brain. Some animals have senses that humans cannot have, but this is only because they have brains that are vastly different than ours. Perhaps our “qualia” are no more than specific brain states. In this view, a bat can have the non-human sense of echo-location only because it can experience different brain states than the average person. The main claim of the type identity theory is thus not disproven by this argument. Mary is kept, by the force of the microchip, from entering the “seeing red” brain state. If one can deduce from the type identity theory that we learn something new only by entering new brain states, then we can deduce that Mary simply didn’t know all there is to know about color. She didn’t know the fact of what brain state (and thus what qualitative mental state) she would be in every time she saw the color red.

The zombie argument, most thoroughly developed by David Chalmers, is sometimes used to call into question the validity of the main claim of functionalism (that mental states are nothing over and above their functional roles). It may also be used (as Chalmers uses it) in a more general attempt to disprove a materialist account of the mind. The argument uses the term zombie to mean a being that is physically and functionally identical to a human being, the only difference being that the former lacks qualitative experience or consciousness. If zombies are conceivable, then Chalmers argues that they are metaphysically possible. If they are metaphysically possible, then materialism is false, because this must mean that the physical make-up of a person is not enough to account for its consciousness.

It is fairly easy to show that this argument is not a very strong one. A materialist’s most defining belief is that consciousness is caused by our physical structure alone. A materialist would therefore not find it even conceivable that a physical duplicate of a human being could lack consciousness. (How can a physical and functional duplicate of something be different in any way from the original if one accepts a materialistic point of view?). Similarly, a functionalist does not find it conceivable, by their defining belief, that a functional duplicate of a human being could possibly lack mental states. The argument provides no original thought that may cause one to doubt materialism or functionalism. It only claims that it is conceivable that these theories are wrong, without any explanation of why they may be wrong.

The third and final argument, the inverted spectrum, poses a problem only for functionalism. One (fairly weak) version of the argument goes like so: imagine waking up one day to find that all of the colors have been somehow reversed in your mind’s eye, but your brain is left unchanged. Is this conceivable? If it is, then qualia exist and are non-physical. This argument, however, suffers the same flaw that the previous argument suffers. According to the materialist and type identity theorist it is inconceivable that this reversal would take place with no change whatsoever in the brain, by virtue of their core beliefs. This argument, like the zombie argument, provides no original thought or evidence that may compel one to reject materialism.

Another more substantial version of the argument poses somewhat of a problem for functionalism. It is clear that every time I see the color red, I get a specific mental image of that color. My friend on the other hand could be seeing a totally different color in his mind’s eye each time he sees what I call “red”. He may in fact be seeing what I see when I look at the color blue. The argument says that if my friend and I are in different mental states even though those mental states are serving the same exact functional role, than mental states cannot be defined by function alone. Thus, functionalism is false. I believe that this version of the argument effectively casts doubt on the claim that mental states are functional roles and nothing more.

It seems that in order to provide an answer to this objection, we must combine some features of both functionalism and the type identity theory. Type identity theory states that each mental state is a unique brain state. Using this line of reasoning, one could conclude that my friend and I may be in two observably different brain states when seeing the color red (simply because our brains are structured differently) and that is why we see different mental images. A functionalist way of thinking could then be used to unite the unique mental states of myself and my friend as the same functional mental state. In this way, mental states are brain processes and brain processes alone, but may be defined and categorized by their functional role. Mental states could be truly unique while still remaining functionally equivalent. This seems to solve the inverted spectrum argument once and for all without relying on any non-physical thing or process.




Works Cited
1. Dennett, Daniel Clement. Brainchildren: Essays on Designing Minds. Cambridge, Mass.: MIT, 1998. Print.
2. Putnam, Hilary. "The Nature of Mental States." 1973. Philosophy of Mind: Classical and Contemporary Readings. By David John Chalmers. New York: Oxford UP, 2002. 73-79. Print.
3. Chalmers, David John. "Consciousness and Its Place in Nature." Philosophy of Mind: Classical and Contemporary Readings. New York: Oxford UP, 2002. Print.