The Value of Experience for Knowledge

by Madeleine Hess, Philosophy


Abstract: This article refutes physicalism, the notion that all facts and information are tangible and originate from the physical sciences, and advocates that experience is essential for knowledge. It engages the main viewpoints of Jackson and Dennett responding to the Mary thought experiment, where a brilliant scientist is forced to examine human color vision through a monochromatic television monitor. The two researchers debate how perceptual sensation will expand her understanding of the visual system to determine the value of experience. Opponents of physicalism maintain that experience will enhance Mary’s knowledge and is directly supported by the existence of the explanatory gap, which asserts that physical information alone is insufficient to convey experience to the fullest extent. This rationale is further investigated using an original hypothetical example to showcase the ambiguity between individual interpretation and physical facts. The physicalist perspective is supported using the Blue Banana example, which asserts that Mary wouldn’t learn a fact by perceiving color since she already possessed all the physical information. However, it’s effectively disproved because it assumes that our perception of the world is stagnant and unable to expand beyond concrete facts. In the end, it’s indisputable that perceptual experiences and bodily sensations are required to advance knowledge.

physicalism, experience, explanatory gap, Jackson, Dennett

Many cognitive scholars have dedicated their studies to explaining the role of perception and experience in obtaining knowledge. One of the most controversial and compelling pieces of evidence pertaining to this topic is Jackson’s thought experiment regarding Mary, a brilliant scientist who’s locked in a black-and-white room and forced to evaluate the world through a monochromatic television monitor. Mary specializes in neurophysiology and possesses all the physical information necessary for color vision (Jackson 130). When Mary exits the room, Jackson asserts that she will learn something about the world and enhance her understanding of the visual system by experiencing color (Wright 3). Jackson, like other “qualia-freaks,” believes that bodily sensations and perceptual experiences are necessary to further knowledge, which is effectively demonstrated by this example. On the other hand, physicalists believe all facts and information originate from the physical, chemical, and biological sciences and that cognition is irrelevant for knowledge (Jackson 127). They maintain that Mary wouldn’t learn anything by experiencing color since she already possesses all the physical information regarding human vision (Dennett 18). Throughout this paper, I will prove that physicalism cannot substitute the value of experience for knowledge. 

It’s evident that there’s a bridge between the physical components of the brain and the phenomenal processes that take place within the mind. Despite many in-depth examinations analyzing the structure of neurons and their subsequent chemical transactions, qualia remain irreducibly subjective and continue to have non-physical attributes. This is known as the explanatory gap and it further supports the necessity of experience for knowledge (Tye ch.5). Having this gap means that even if someone revealed all the physical information, it would still inadequately convey the extent of an experience. In other words, you can tell me everything physical about a subject without actually telling me what it’s like. This rationale is substantive evidence supporting anti-physicalism and is visible throughout the Mary thought experiment. Even though Mary knows all the physical facts about human color vision while in her black-and-white room, she still enhances her knowledge by exiting the room and experiencing color for the first time. Mary learns what the color red looks like through sensation, therefore, not all facts are physical facts and physicalism is insufficient (Wright 3). Furthermore, it proves that while someone may have access to every physical fact, they still don’t possess all the possible information relevant to a topic since experiences function as their own source of knowledge (Jackson 130). 

To investigate the role of experience for improving knowledge, I propose a new thought experiment which emphasizes the ambiguity between physical information and interpretation. Suppose your friend just returned from a beach vacation and begins recounting their trip. They provide a detailed account of the crystal blue water, the saltiness of the air, and the sound of squawking seagulls and crashing waves. Imagine your friend is so enthusiastic about their getaway that they describe every possible physical detail down to the very last grain of sand. Although your friend has relayed every tangible fact about their trip, you still cannot fully understand the experience or personally attest to the resulting sensations without having gone on the trip yourself, which further supports the notion of the explanatory gap and aligns with Jackson’s original premise (Jackson 127). Now, imagine your friend also shares the extensive details of their vacation with your classmate, making them imagine what it would’ve been like to explore the beach too. However, despite having received the same verbal description, both you and your classmate happen to picture slightly different versions of the beach. This is because you both individually interpreted the physical information to best understand what it would’ve been like for each of you to have personally experienced the vacation, further demonstrating the inability of physicalism to substitute experience. Physical facts are irrefutable concepts that are equally understood from multiple points of view, therefore, these differing yet accurate depictions prove that the physical information alone wasn’t enough to convey the full extent of the vacation without experience (Jackson 132). 

Despite the clear notion that experience is necessary for knowledge, physicalists attempt to defend their position using Dennett’s Blue Banana example which argues that Mary wouldn’t learn a fact by perceiving color. In this scenario, Mary’s experimenters decide that they will deceive her and present a bright blue banana instead of a yellow one during her first color experience. Prior to the deception, Mary is taught that a banana can only ever be yellow, light green if not ripe, or brown if rotten, but never blue. Moreover, since she already possesses all the physical information regarding human color vision, physicalists maintain that she would be able to discern all colors without having experienced them. They assert that Mary wouldn’t be fooled by the bright blue banana or expand her knowledge by perceiving color for the first time because there was nothing more for her to learn (Dennet 15). This hypothetical refutes our original claim that perception is essential for knowledge since Mary didn’t gain any new knowledge through sensation. If Mary did happen to learn something by exiting the room, it would’ve only happened because she didn’t have access to all the physical facts beforehand. In all, Mary’s ability to sense the banana’s color using only physical information in this thought experiment is compelling evidence for physicalism and disputes the necessity of experience for knowledge. 

While physicalists make a valiant effort to undermine the importance of experience, their arguments are undoubtedly short-sighted. Physicalism asserts that our knowledge solely depends on the tangible information provided by our environment. It eliminates any possibility that our current scientific practices are deficient or unable to explain entire phenomena. It implies that scholars are unable to expand their knowledge beyond physical terms because they should already have access to all the facts. Therefore, physicalism assumes that our perception of the world is stagnant and unable to improve in light of new information because our minds require concrete evidence and disregard conceptual theories. To put these claims into perspective, let’s theorize an intellectual species of sea slugs who live at the bottom of the ocean in a very restrictive environment. These creatures are assumed to have an extremely limited conception of the world compared to ours because their knowledge relies on their immediate surroundings (Jackson 136). If we apply the principles of physicalism to this colony of sea slugs, we assume that they will always be subservient to humans because they’re unable to advance beyond the physical information provided by their environment even though more knowledge exists in our society. If this were the case, it would completely undermine the ability of humans to evolve past the physical limitations of their environment. Returning to our previous hypotheticals, the physicalist assertion that Mary would learn nothing by experiencing color conveys an exceedingly limited and improbable perspective which greatly undermines the capability of the human mind. Additionally, it disregards the ability of the human brain to uniquely interpret information and assumes the existence of only one right answer, which entirely rejects the premises of our beach thought experiment. It’s obvious that this perspective assumes humans to be completely objective entities whose brains can only depict physical information in limited contexts because it discounts the innate value of experience. 

It’s undeniable that bodily sensations and perceptual experiences are essential for knowledge, which is directly supported by the existence of the explanatory gap. This gap maintains that despite having all the physical information, one can never fully understand the extent of an experience without perceiving it themselves. Furthermore, the explanatory gap supports anti-physicalism and is evident throughout the Mary thought experiment. This experiment argues that Mary would enhance her knowledge by experiencing color for the first time, therefore, not all facts are physical facts and physicalism is insufficient. Additionally, the multiple depictions of the hypothetical beach showcase the discrepancy between physical facts and interpretation and proves that experience is subjective. Even when considering the opposing arguments, it’s indisputable that experience is crucial for expanding knowledge. 

Works Cited

Dennett, Daniel C. “What Robomary Knows.” PhilPapers, Oxford University Press, 2006,

Jackson, Frank. “Epiphenomenal Qualia.” The Philosophical Quarterly, vol. 32, no. 127, Apr. 1982, pp. 127–136,

Tye, Michael. “Qualia (Stanford Encyclopedia of Philosophy).”, 2017,

Wright, Sarah. “Jackson.” Introduction to Cognitive Science, 11 Oct. 2023, University of Georgia, GA. Lecture.

Acknowledgements: I would like to thank my inspiring teaching assistant Danielle Kotrla for her continuous academic support and writing guidance.

Citation Style: MLA