In Jackson's essay “Epiphenomenal Qualia,” several arguments are made; perhaps the most popular of these arguments is the knowledge argument for qualia involving a brilliant scientist named Mary. In Jackson's example, Mary is:

for whatever reason, forced to investigate the world from a black and white room via a black and white television monitor. She specializes in the neurophysiology of vision and acquires, let us suppose, all the physical information there is to obtain about what goes on when we see ripe tomatoes, or the sky, and use terms like ‘red’, ‘blue’, and so on. She discovers, for example, just which wavelength combinations from the sky stimulate the retina, and exactly how this produces via the central nervous system the contraction of the vocal chords and expulsion of air from the lungs that results in the uttering of the sentence ‘The sky is blue’. (It can hardly be denied that it is in principle possible to obtain all this physical information from black and white television, otherwise the Open University would of necessity need to use color television.)

What will happen when Mary is released from her black and white room or is given a color television monitor? Will she learn anything or not? It seems just obvious that she will learn something about the world and our visual experience of it. But then it is inescapable that her previous knowledge was incomplete. But she had all the physical information. Ergo there is more to have than that, and Physicalism is false. (Jackson).

Jackson notes that this argument could be also used for any of the other senses that humans posses. For that matter, it is not necessary that the visual example that Jackson provides be on the subject of color either. We could, instead, use the example of “a blind Mary who learns from texts,” and one day acquires the ability to see the world around her (Goldberg & Pessin 252). What is important is Jackson's central idea that, through this process, Mary gains some sort of knowledge that, given her previous condition, she could not have had access to by factual information alone.

Jackson makes a strong argument, but I ultimately disagree with his case for nonphysical qualia. Dennet insists that part of Jackson's premise is misleading, and his belief is understandable. It is quite impossible for any normal human being to obtain all of the physical information as described in Jackson's example; for this reason, Jackson's argument may be slightly misleading to some. Although we may be able be able to readily imagine that Mary does have access to a great deal of physical information, we must consider the ramifications of Mary having all of the possible physical information. If, in the example, Mary has this information, say, stored on some sort of supercomputer connected with her brain, she will know “precisely which effects [. . .] each color will have on her nervous system” (Dennet 400). With this knowledge, Mary should be able to differentiate colors immediately upon exiting her black and white room. With all of the physical information, she should easily be able to observe the reactions going off inside of her head, associating objects with the respective chemical reactions that occur in the brain that are present upon viewing an artifact of color. In fact, it has been argued that “if it were possible to know every physical fact about the world, then we would know what colours looked like before we happened to experience them” (Silby). The idea does seem plausible that, if we were to know which neural events would occur upon encountering a certain color, that we could get an idea of what sort of sensation we would experience. Indeed, it is possible with even the knowledge we posses, which is much less than that of Mary, to imagine some sensations before actually experiencing them. Most of us have never had a cold steel sword slice through our bodies, or felt the stimulus of acid eating away at our hands, yet we still cringe in pain when we see these things happen to characters in the movies. It seems intuitive that that we have some idea of how the sensations we would feel if we were to experience them, and Mary, with the extreme amount of knowledge that she has, would surely be able to predict sensations such as these much more clearly and accurately. This is, put simply, Dennet's argument, which seems to be receiving a lot of support. In essence, he “is trying to convince us that it if were possible to know every physical fact about the world, then we would know what colours looked like before we” experienced them (Silby). While Dennet makes a strong case, I would also like examine Churchland's reply to Jackson's thought experiment.

Churchland takes a slightly different approach in trying to invalidate Jackon's argument. In the essay “Knowing Qualia: A Reply to Jackson,” Churchland looks at two premises in Jackson's example. He notes that Mary, before being released, “knows everything physical there is to know about other people;” he also acknowledges the premise that, before here release, Mary “does not know everything there is to know about other people” (Churchland). The second premise here is true because she is supposed to learn what a color “is like” after experiencing it for the first time. Churchland insists that we are missing something from the physicalist picture in Jackson's story. His claim is that “neurobiology already provide[s] us with a plausible account of” knowing everything physical there is to know about others, and knowing everything there is to know about others (Churchland). Churchland goes on to explain how color is stored in the brain. Information for color, he explains, exists as a pattern across the optic nerve. The information is ultimately transmitted to the occipital region of the brain; specifically, the data goes to an area called V4, an area that seems to be “especially devoted to the processing and representation of color information” (Churchland). The V4 area seems be partitioned into distinct areas to discriminate between prototypical colors. When a certain pattern of activity hits one of these areas of the partition, it appears that a specific color is recognized. It is important to note that recognition is learned, and it can be assumed that Mary will not have subspaces to recognize the many colors others are able to see. Instead, her area of partitions should “contain only the subspace[s] for black, white, and the intervening shades of gray” (Churchland). Churchland notes that, based on these accounts of neurology, Mary is indeed lacking something physical. It is plausible, by this account, that if Mary were to some how artificially change the physical makeup of her brain, she could know what color was. This makes Churchland's case seem credible, and certainly presents some challenges to Jackson's position.

Up until this point, we have seen Dennett challenge the idea in Jackson's example that Mary must necessarily learn something new, and we have examined how Churchland argues that Mary's conundrum can be explained by entirely physicalist means. If these arguments hold up, as I believe they can, the example of Mary's black and white room as an example supporting qualia must be abandoned. The reader should note, however, that Dennet and Churchland's examples can only go so far as to show that the experiences of Mary can be answered entirely by physical means. Disproving qualia as nonphysical entities by empirical means is, presumably, not a possibility. This, scientifically speaking, actually weakens the argument for their existence, and we should be very careful before we assume that certain phenomena, such as the apparent existence of qualia, are nonphysical, or transcend human understanding in some way. New frontiers of science are still ahead of us, and there is likely a lot of information yet to be discovered that might add to our knowledge of the world around us. While in the future we may one day hit a road block that shows a limit on what we can discover or comprehend, we have, in the past, gained more insights into the universe than anyone would have likely been optimistic enough to predict. For this reason, we should not be dismissing our apparent experiences of qualia away as nonphysical and unapproachable by science, but rigorously test our ideas in neurology to see what results we can obtain. As for the thought experiment involving Mary and her black room, we have seen that there are at least two plausible responses to examine before resigning ourselves to introducing a new world of nonphysical qualia. Both the arguments of Dennet and Churchland show us why the example of Mary falls short of giving us a conclusive proof for the existence of qualia.

"Qualia." 16 Feb. 2005. Wikipedia. 26 Feb. 2005 <http://en.wikipedia.org/wiki/qualia>. 

Jackson, Frank. "Epiphenomenal Qualia." Philosophical Quarterly 32. (1982): 127-136. 26 Feb. 2005 <http://instruct.westvalley.edu/lafave/epiphenomenal_qualia.html>;.

Goldberg, Sanford, and Andrew Pessin. Gray Matters: An Introduction to the Philosophy of Mind. Armonk: M. E. Sharpe, 1997. 252-262.

Dennet, Daniel C. Consciousness Explained. Boston: Little, Brown and Company, 1991. 398-406.

Silby, Brent. The Problem of Qualia. 1998. Dept. of Phil., University of Canterbury. 26 Feb. 2005 <http://www.def-logic.com/articles/silby014.html>.

Churchland, Paul M. Knowing Qualia: A Reply to Jackson. 1989. 26 Feb. 2005 <http://www.clas.ufl.edu/users/maydede/mind/Churchland.ReplyToJackson.pdf>.