The knowledge argument, first put forward by Frank Jackson in 1982, is a powerful criticism of physicalism. Despite Jackson’s withdrawal of support for this argument, it remains highly significant in the philosophy of mind. Physicalism, a metaphysical belief, claims that everything in our world – cars, humans, animals, research papers, and even our sensations – ultimately possesses a physical nature.
The knowledge argument seeks to challenge this claim by presenting a hypothetical situation called “Mary’s Room.” Mary is confined within a room that lacks color, learning exclusively from black-and-white books and lectures conveyed through black-and-white television. Through this method, she acquires complete knowledge regarding the physical properties of the universe.
According to Jackson (1986, p. 291), Mary possesses extensive knowledge about the physical aspects of both humans and our surroundings. This encompasses a broad definition of “physical” that includes all established principles in physics, chemistry, and neurophysiology, as well as an understanding of the causal and relational facts derived from these disciplines, including functional roles. The knowledge argument suggests that if physicalism is indeed valid, Mary would possess comprehensive knowledge about everything in our world. However, it is evident that Mary cannot have acquired absolute knowledge solely from her own experiences.
Once Mary is freed from her black and white environment, she is able to experience and learn about color. This newfound experience challenges the idea of physicalism. Prior to her release, Mary already possessed knowledge of all the physical facts about color. However, her exposure to actual color brings about new understanding, supporting the argument against physicalism. A simplified version of this argument is presented by Jackson: 1) Mary possesses knowledge of all physical facts about color while in the black-and-white room. 2)
Mary gains insight into color experience after leaving the room, implying that she lacks complete understanding of color experience while inside. Consequently, she lacks full knowledge of color experience in the room. As a result, there exist non-physical facts about color experience. If physicalism holds true, all facts are physical, thereby indicating that physicalism is false. Additionally, objections can be raised against many philosophical arguments, including Jackson’s. I will explore the four most influential objections to this particular argument. The initial objection challenges the conjunction of the first and second premises, asserting that Mary cannot possess knowledge of every physical fact unless she personally experiences seeing the color red. This objection establishes the limitation behind Mary’s newfound knowledge upon her release. Daniel Dennet further argued that it is impossible to know all relevant physical facts, suggesting that if premise #1 is accurate, premise #2 must be inaccurate.
Defenders of the knowledge argument argue against Dennet’s claims by stating that the argument only requires us to understand the basic knowledge that Mary possesses while she is in her black and white world. They believe that because we can comprehend the physical facts that Mary knows, we have the ability to assess the possibility that (1) and (2) are simultaneously true. The following two objections to the knowledge argument focus on disproving premise #3. According to Churchland (1985), Mary gains a “knowledge by acquaintance” of what it is truly like to see and experience the color red after she is released from the room.
According to Churchland, by applying this analysis, an argument that is parallel would also reject the concept of dualism. This is because even if Mary has a vast amount of propositional knowledge about the nonphysical, she still lacks sufficient “knowledge by acquaintance.” In 1986, Jackson responded to Churchland’s refutations by stating that it is possible to have complete knowledge of the physical facts related to experiencing the color red without actually experiencing it firsthand. However, one cannot possess complete knowledge of both the physical and nonphysical aspects of seeing red without having the subjective experience of what it is like.
Another objection to the argument, refuting the third premise, asserts that the benefits Mary acquires upon leaving the room are not about knowledge, but rather about an ability. This objection was initially raised by Laurence Nemirow in his analysis of Nagel’s argument in 1980. David Lewis also supported this objection in 1988. When delving into this newfound “ability” of Mary’s, it is claimed that she learns how to identify and recall the experience of “seeing red.”
Having experience is a necessary condition for possessing these abilities, but it does not imply that physicalism is false. Moreover, having extensive propositional knowledge alone does not ensure that a person has the necessary ability. If that were the case, experts in a field like engineering would be able to excel in any profession, such as being a basketball player, simply by knowing all the relevant facts about shooting a basketball into a hoop.
The prevailing objection to Jackson’s Knowledge Argument centers around rejecting premise #6. This objection contends that what Mary acquires is merely a novel way of depicting a previously known portion of reality. It suggests that our methods of representing reality might be more detailed than the reality itself. Essentially, this objection asserts that Mary did not actually learn any new information, but merely encountered familiar facts presented in a fresh manner.
In 1993, Jackson accepted the idea of epiphenomenalism and acknowledged the absence of an obvious fallacy in the Knowledge Argument. However, he concluded that its assertion of physicalism being false must be incorrect. By considering his own conclusion as false, Jackson suggests a flaw in the argument itself. Therefore, if physicalism is claimed to be false in the Knowledge Argument’s conclusion, but it is not, it implies that the argument is unsound for some undisclosed reason.
The advantages of adopting physicalism should be explored, as it aligns with the prevailing worldview of modern science, known as the principle of physicalism. It would be an error to assume that philosophy has the authority to amend scientific findings. However, embracing physicalism also presents drawbacks concerning our intuitive beliefs regarding values, free-will, experience, and other matters.
Overall, I have argued that The Knowledge Argument poses a challenge to physicalism. However, its importance extends beyond just opposing physicalism as it has generated varied and thought-provoking responses. As a result, this argument has influenced discussions on various topics including the differences between propositional knowledge and ability, the relationship between identity and deducibility, and the distinct qualities of phenomenal knowledge.
The majority of philosophers generally reject the argument, while a smaller group accepts it as valid. Key references include:
Churchland, Paul. “Reduction, Qualia, and the Direct Introspection of Brain States.” Journal of Philosophy 82(1985):8-28.
Dennett, Daniel. Consciousness Explained. Boston: Little Brown and Company, 1991.
Jackson, Frank. “Epiphenomenal Qualia.” The Philosophical Quarterly 32(1982):127-136.
Jackson, Frank. “What Mary Didn’t Know.” The Journal of Philosophy 83(1986):291-295.
Nemirow, Laurence. Review of Mortal Questions Thomas Nagel. Philosophical Review 89(1980):473-477.
