Jackson's Essay 'What Mary Didn' T Know

What Mary Didn’t Know

Malia Mandl

Philosophy 101

Jackson’s paper What Mary Didn’t Know presents and clarifies a thought experiment is intended to argue against physicalism, the view that everything is physical when it is broken down to its most basic properties. The paper starts off by setting Mary up in a black-and-white room where she is, and always has been, solely exposed to a black-and-white world. Mary is an intelligent scientist who knows everything that can be known about the physical properties of colors. The question is, when she is finally exposed to color, will she learn new factual knowledge or not? Jackson uses this thought experiment to claim that if Mary does, in fact, learn new factual knowledge upon experiencing color, then

qualia are non-physical and they are epiphenomenal, which serves as an argument against physicalism. At the end of this article he also makes clarifications and addresses objections by Churchland. Although Jackson sets up a good thought experiment, there are several points in which his argument can be disputed.
Mary knows every piece of physical knowledge in about human color prior to her release from the black-and-white room. She specializes in the neurophysiology of vision. Mary comes to know all of the physical facts about color vision through a black-and-white television. These facts include the nature of causal interactions between the surface reflectance properties of objects, wavelengths of light, and retinal stimulation. She will also know exactly how this produces the contraction of one’s vocal chords via the central nervous system and results in one saying: “the sky is blue.” This premise should just be granted, as it is a fantastical setup, but it must be established in order to engage with this thought experiment.
Jackson then asks: “What will happen when Mary is released from her black and white room?” The second premise that Jackson states is that when Mary leaves the room and witnesses color first-hand, she will obtain new knowledge. He answers, “It seems just obvious that she will learn something about the world and our visual experience of it.” He reasons that Mary will finally learn what it is like to see and experience the color red. According to Jackson, all of her knowledge on the color red could not prepare her for the actual experience of seeing red.
The more important question that Jackson raises is: once she experiences color, does she learn anything new? Jackson claims that there is an epistemological gap in Mary’s experience that can only be filled once she leaves her black and white room for the first time and learns something new, specifically, the qualitative experience of what it is like to see or experience the color red. He answers this question by saying that the knowledge that Mary gains after leaving the room is new to her: “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, 1982) The implications of this are that if Mary does in fact learn something new, then qualia must exist. This also entails that there is a difference between people who have had access to particular qualia and people who haven’t, hence it must be granted that qualia are real properties. This would also imply that physicalism, the principle that all information is physical information, is false. Although Mary may know everything possible about the science of color and color perception, she cannot know what it is like to experience red before having ever experienced it.
After this Jackson goes on to clarify certain aspects of his paper. In the first clarification, he explains that the important distinction isn’t that Mary couldn’t imagine red, but instead that she would not know what it is like to sense red. According to Jackson, imagination is a faculty that those who lack knowledge fall back on. His second clarification explains that Mary is not lacking knowledge that could be “remedied merely by her explicitly following through enough logical consequences of her vast physical knowledge”, and that bequeathing her with vast logic does not alone fill the gaps in her knowledge. Jackson states that: “on being let out, she will not say ‘I could have worked all this out before by making some more purely logical inferences.’” She understands every relationship between certain things and their equivalencies, and she is not lacking the ability to process complex deductions or reasoning in order to find relationships between everything in existence.
Finally, his third clarification states that the knowledge that Mary lacked is “knowledge about the experiences of others, not about her own.” When she is let out of her black-and-white room, she has new color experiences that she has not had before. Jackson then asserts that it is not an argument against physicalism to say that she learns something upon being let out. He says that both physicalists and nonphysicalists can agree that some physical things, namely her brain state, will change. But he also asserts that after Mary first sees a ripe tomato, she will realize that there was something about the people who had experienced this image that she was unaware of. Although she had carried out countless investigations regarding the neurophysiologies of others and their internal states, she still could not know this feature of color experience. This missing knowledge of the experiences of others is what cannot be explained by physical facts. And this, he asserts, is the trouble for physicalism.
Jackson later goes onto address Churchland’s three objections, all of which he nullifies by further clarifying his argument. The first thing that Churchland claims is that Jackson’s argument is stating that Mary understands everything there is to know about brain states, but not everything there is to know about sensations. From this, he concludes that brain states must not be equal to sensations. Jackson clarifies his argument after this objection by stating that Mary, before her release, doesn’t actually know everything there is to know about brain states because she does not know about the qualia associated with these brain states. Therefore Jackson proves Churchland’s first premise wrong.
Churchland’s second objection states that Jackson’s argument must be wrong because it proves too much.

Churchland states that Mary could have “received a special series of lectures over her black-and-white television from a full-blown dualist, explaining the “laws” governing the behavior of “ectoplasm” telling her about qualia.” He uses this to show that this would not affect the plausibility of the claim that upon her release Mary still learns something. Churchland is saying that this argument would work for dualism as well. Jackson replies by stating this cannot be true because the lectures could not tell Mary everything about qualia. On the other hand, he deduces that to build a good argument against dualism, all that must be done is to replace the premise that she knows everything, and make it so that she is all knowing, according to dualism. This is impossible and does not even make sense and therefore there is no “parity of reasons” as Jackson states. Churchland’s last objection is that Jackson’s argument claims that Mary could not even imagine what the relevant experience would be like and he goes on to argue against this claim. However, this claim was already addressed earlier in Jackson’s article in the first clarification. The knowledge argument claims that Mary wouldn’t know what the relevant experience is like and her imagination is

irrelevant.
There are several different points at which Jackson’s argument can be disputed. The first point in Jackson’s paper that can be easily disputed is Jackson’s assertion that upon leaving the room and witnessing color first-hand, Mary obtains new, factual knowledge. This argument can be disputed in many ways and perhaps the easiest way to dispute it is to claim that Mary did gain something when leaving the room, but what she gained was not new knowledge. It is easy to agree that Mary must gain something when leaving the room, but what can be disputed is what exactly that something is.
When Mary steps out of the room, it can be argued that what she gains are only baseless beliefs.

The reason Mary believes she has learned something new has nothing to do with her new acquaintance with color qualia, but instead relates to her visual cortex. After leaving the room, her visual cortex operates the way that cortexes do in other people. What she gains is merely an ability to recognize what seeing red is like, and an ability to remember this new experience. The fact that she needs experience for this ability does not actually carry any anti-physicalists properties. It is easy to recognize that an extensive propositional knowledge does not always guarantee that one also possesses the relevant ability to this knowledge. Although Mary may have known everything there is to know about color and color experience, this does not necessarily mean that she must also have possessed the ability to recognize, remember, or imagine seeing red. If extensive knowledge entailed the relevant ability, then ice hockey teams would be made up of extremely smart physicists who knew everything there was to know about the relevant facts of skating and shooting a puck into the goal. Mary has merely gained the ability to have her own visual cortex function in a new way that others are accustomed to, but she has not actually gained new knowledge about color

qualia.
The premise states that Mary has a complete knowledge of color and what effects experiencing color have on a human nervous system. This knowledge includes the studying of subjects that are exposed to color and their brain states. Mary could then study a subject who is looking at a tree. The visual phenomenal quality of this subjects experience is captured by his brain state and his brain state represents that he or she is looking at a tall, green thing. And since Mary can, in principle, study this subject’s brain and know the contents of his or her brain state, then she can, in principle, know all there is to know about what it is like to see a tree and therefore also the color green. She would also be able to predict that once she is able to leave the room and experience color first hand if she was shown a tree she would say to herself, “Wow, that’s what a tree looks like” when she first saw the tree. She knew in advance, however, the effects the tree would have on her nervous system. Therefore, she is not surprised by her behavior in reaction to seeing a tree. The claim that Jackson makes that Mary learns something new depends upon the fact that when Mary experiences these new qualia she is genuinely astonished or surprised. Consequently, since Mary isn’t genuinely surprised or astonished at the sight of a tree, the reasons that initially lead to the belief that Mary had learned a new thing start to disappear.
Furthermore, if Mary did, in fact, already know everything about every color and the effects of these color on visual cortices and the effects of this on one’s nervous system, then this would probably include a deep understanding of why and how human neurology helps us sense color. Subsequently, within this knowledge Mary would be able to differentiate between colors and would know exactly what to expect when she saw red when she left the room. Jackson’s argument is not a good argument for the existence of qualia because the knowledge that Mary supposedly knows before leaving the room would be identical to her experience, so there is no qualia left over.
The experience of red is entirely contained in the brain and this experience immediately causes further changes in the brain (i.e. creating new memories). This suggests that Mary is simply discovering a new way for her brain to represent qualities such as color, that exist in the world. This can be seen in someone who has prosopagnosia, a cognitive disorder where the ability to recognize other’s faces is impaired while other visual processing remains intact. If someone was cured of this they would not be surprised to discover that their spouse has a face, but rather, their surprise would come from their brain now functioning normally and allowing them to see their spouse’s face.
Jackson’s paper What Mary Didn’t Know presents a thought provoking experiment. This paper is intended to argue against physicalism and uses logical steps in order to do so. The first premise is that Mary knows every piece of physical knowledge in regard to color prior to her release from the black-and-white room. The second premise is that once Mary leaves the room and witnesses color first-hand, she obtains new knowledge. Jackson’s conclusion is that since she learned something new upon leaving her room that she did not know through her intensive studies, some non-physical truth must exist. After this argument, Jackson goes on to clarify and address Churchland’s objections to his paper. Although Jackson sets up a good thought experiment, there are several points in his argument where he leaves room for dispute. It is easy to agree that Mary must gain something when leaving the room, but what can be disputed is what exactly that something is. One thing that can be argued is that Mary solely gains new ability. And since Mary has extensive knowledge on human neurology and how people sense color, she would therefore be able to differentiate between colors and would know exactly what to expect when she was exposed to them for the first time. It can therefore be argued that Jackson’s premise could be rejected, which would consequently make his conclusion incorrect.