Driving Society Forward.
‘Mary could know all the physical facts, but not know what it is like to see red. So physicalism is false.’ Discuss.
An essay written as an undergraduate in the Department of Philosophy, King's College London
London, June 2010
Frank Jackson uses a thought experiment involving a person called Mary in his “knowledge argument”. Physicalism is the thesis that the world is entirely physical. And Jackson says that since Mary can know all the physical facts, but not know what it is like to see red, there must then be non-physical facts involving non-physical conscious properties. I will show that the ability hypothesis given by Lewis is an inadequate response to Jackson. I shall also discuss the positions of Loar and Papineau, who both maintain that since Mary did not know what it is like to see red, she did not have the phenomenal concept which immediately refers to the physical property of having a red experience. An anti-physicalist though, may be unsatisfied with the conception of ‘facts’ that Papineau and Loar are using. However, I shall finish the essay by giving Crane’s point that: even if we accept that there are non-physical facts, this does not necessarily mean that physicalism must be false. I argue that even if we take facts to be what the knowledge argument takes them to be, the argument still fails to successfully refute physicalism.
Jackson gets us to imagine that Mary has been in a black and white room her whole life. The only colours she has ever seen are black and white. However, Mary has learnt all the physical facts about the world from her science books. Jackson says: “In this way she learns everything there is to know about the physical nature of the world” . Now, according to physicalism, all facts are physical facts, believes Jackson. As Jackson says: “If physicalism is true, she [Mary] knows all there is to know” . So, if Mary extents her knowledge from leaving the room, then physicalism must be false, says Jackson. But Jackson says that Mary learns something new when she leaves the black and white room. From leaving the room, Mary learns what it is like to see red. So, not all facts are physical facts. “Hence, physicalism is false” , concludes Jackson.
Physicalism says that the world is completely physical, and Jackson believed that his knowledge argument has proven that physicalism must be false. What he is saying is that, there must be properties of conscious mental states which are non-physical. Upon leaving the room, Mary learns what it is like to see red. And many now accept Nagel’s conception of consciousness. Nagel states: “…an organism has conscious mental states if and only if there is something that it is like to be that organism” . For Nagel, a conscious mental state is a state that feels a certain kind of way to be in. Papineau (2002, p. 48) gives the example of a tooth-ache. He says that we can be in a conscious mental state of having a painful feeling in a tooth. Assuming that Nagel’s conception of consciousness is right, this poses a problem for physicalists, as it appears that the knowledge argument proves that there are non-physical facts involving non-physical conscious states, such as the state of seeing red, for example.
David Lewis acknowledges that to know what a new experience is like, we must undergo that experience for ourselves. He gives the example of tasting vegemite. He himself has never tasted vegemite, but he says that in order for him to know what vegemite tastes like, he needs to experience tasting it for himself. As Lewis says: “You can’t learn it by being told about the experience, however thorough your lessons may be” . If Lewis does taste vegemite, then from tasting it, he will be able to imagine and remember what vegemite tastes like (Lewis, 1997, p. 592). Just like Mary, the knowledge Lewis has would then be extended due to a new experience. However, this new piece of knowledge gained is a specific kind of knowledge, says Lewis. The knowledge that both Mary and Lewis would have gained is knowing-how rather than knowing-that (1997, p. 593). When Mary leaves the room, she does not gain any new information about the world, says Lewis. But, what she does gain is an ability to imagine and remember what it is like to see red—she gains know-how. According to Lewis, the knowledge argument falsely assumes there is only one kind of knowledge. He says: “Lessons impart information; ability is something else” .
Some explain that what Lewis is saying is that, Mary does not gain any new propositional knowledge when she leaves the room (Van Gulik, 1997, p. 560). I take propositional knowledge to be knowledge which represents the world in some kind of way. According to Lewis, Mary only gains a new ability to remember and imagine seeing red, but she does not learn any new facts. And as a physicalist, Lewis would maintain that Mary would only be able to do all this because of her physical properties. However, it could be said that Mary does in fact extend her propositional knowledge. After all, from learning what it is like to see red, she could make new judgements about the world. She could represent the world by thinking that she is currently looking at a red object (Nida-Rumelin, 2002, p. 13). And whether such a thought is true or not depends on whether the object she is seeing really is red.
Lewis would respond to the above objection against the ability hypothesis by saying that, when leaving the room, Mary was simply able to use the material/scientific concepts she already had in new ways. Since Mary already knew all the physical facts, she already knew about all the physical processes that go on in a person when they see a certain colour; and after leaving the room, Mary is then able to use her old scientific concepts in a new way. However, this seems mistaken, as we can easily imagine a person having no scientific knowledge at all, but yet still being able to represent the world by judging that they are seeing red. And from learning the use of words, such a person can linguistically express such a judgement. It seems that Mary gains a new kind of propositional knowledge when she leaves the room. Papineau explains that when Mary leaves the room, she would not be able to know which exact colour she is seeing just by using her old material concepts. If she knows that she is seeing red, then she must be thinking in a new kind of way. As Papineau says: “This shows that Mary cannot be thinking just using her old material concepts” .
Jackson would say that knowing what it is like to see red is to do with knowing about some non-physical conscious state. As Papineau says, this conscious state would be “…the ‘conscious feel’ of red experience” . However, even if Mary extends her propositional knowledge when she leaves the room, this does not necessarily mean that physicalism must be false. Loar and Papineau for example, both say that when Mary leaves the room, she merely acquires a different concept of red experience. These philosophers say that Mary acquires a new phenomenal concept. They explain that the property of seeing red is a material property that can be thought of in two different ways. Red experience can be thought of by using either a material concept or a phenomenal concept. And by ‘concepts’, I am thinking about components of thoughts that contribute to the truth or falsity of those thoughts (Papineau, 2002, p. 59).
After leaving the room, Mary may eventually associate the word “red” with the colour red. However, she would only be able to do so by thinking about her red experience. But how do phenomenal concepts work? One thing to take note of is that, seeing red is a certain kind of experience, and that a certain phenomenal concept enables us to recognise that experience. As Loar says: “Phenomenal concepts belong to a wide class of concepts that I will call recognitional concepts” . When Mary leaves the room, even if she does not first of all associate the word “red” with her new red experience, she will still recognise that the experience she is having is a new kind of experience. Simply by recognising that she is having a new kind of experience, she is using a new phenomenal concept (Papineau, 2002, p. 57). And to correctly judge what experience she is having, Mary needs to think of that experience by using the right phenomenal concept for doing so.
We are told that phenomenal concepts do not refer in the way material concepts do. Material concepts refer via description (Papineau, 2002, p. 48). When thinking about red experience, we can think of it by using a material concept, and we use this concept to think about the causal relationships between physical properties during a red experience (which is what Mary did in the room). Papineau explains that we use material concepts to refer to physical properties, by describing such causal physical relationships. But phenomenal concepts refer directly, we are told. By using them, we are thinking about what it is like to undergo a certain experience. Papineau (2002, p. 59) says that from leaving the room, Mary can imagine what it is like for other people to see red. But Papineau also says that: “And her new introspective powers will also allow her to think thoughts like ‘This is what people experience when they look at ripe tomatoes’” . Papineau thinks that Mary can only do all this by using certain parts of her physical brain.
For Papineau and Loar, conscious mental states are identical to physical states, but these states can be thought of by using two different types of concepts. For them, the knowledge argument does not successfully refute physicalism, as from leaving the room, Mary just gains a new way of thinking about the physical state of seeing red. Papineau (2002) maintains that, even though it may seem to us that conscious mental states are not identical to physical states, this is a mere illusion. It would only seem to us that conscious states are non-physical if we fail to fully recognise the distinction between material and phenomenal concepts.
Both Papineau and Loar think that from learning what it is like to see red, Mary just gains a new way of referring to a fact she already knew. However, an anti-physicalist may say that Papineau and Loar are not thinking about facts in the correct way. Crane illustrates that the knowledge argument assumes a notion of facts in the following way: “’Fact’ simply means object of knowledge” . The knowledge argument also takes physical facts to be facts which are learnt just by studying books of physical science. Also, the knowledge argument indicates that physicalism is the thesis that every fact is a physical fact (Crane, 2001, p. 98). If we accept all this, then it seems as though Mary does learn a non-physical fact when she leaves the room. From learning what it is like to see red, she could judge that the rose just outside her old room is red, for example. Mary may also learn language sufficiently well enough to express such a judgement. And if that particular rose is red, this would be a non-physical fact (as it cannot be learnt just from reading science books). So, it seems that physicalism is refuted after all.
However, even if we accept that all physical facts are facts learnt in science books, this does not necessarily mean that physicalism is false. A physicalist need only say that every state in the world is a physical state. The knowledge argument is an epistemological argument—it is about what Mary knows. However, physicalism is a metaphysical thesis—it is a thesis about the nature of the world. We may know many non-physical facts from our own perspective. Crane (2001, p. 98) gives an example of Perry, who notices that someone must have a hole in their sugar bag in a supermarket, as he sees a trail of sugar there. Perry then realises the fact that, it is his own sugar bag which has a hole in it. There are some facts we just cannot learn from science books, Crane rightly points out. However, all this need not worry physicalists. Physicalists need only to maintain that every state in the world is a physical state, and that there are some non-physical facts which are known from having a certain perspective. In one sense, it does not matter what Mary knows. As Crane says: “surprising as it may seem, a physicalist can sensibly deny that all knowledge is physical knowledge” .
Physicalism says that every state in the world is a physical state. Jackson believes that since Mary can know all the physical facts, but not know what it is like to see red, then physicalism must be false. He thinks that conscious mental states, like seeing red, must be non-physical. I take a conscious mental state to be a state that feels a certain kind of way to be in. Papineau and Loar responded by talking about universal facts concerning the nature of the world. An instance of me seeing red for example, would be a particular instance of what it is universally for a human to see something red. Papineau and Loar are saying that these universal facts are physical facts concerning physical properties. They say that from learning what it is like to see red, instead of learning a new fact, Mary just learns a new way of thinking about a fact she already knew.
However, it may be said that Papineau and Loar are not talking about ‘facts’ in the way the knowledge argument does. The knowledge argument takes any object of propositional knowledge to be a fact. Yet, even if we accept that physical facts are learnt from only science books, and that Mary learns about new non-physical facts when she leaves the room, this does not mean that physicalism is false. Physicalism makes a metaphysical claim that every state in the world is a physical state; and what Mary knows is actually irrelevant to whether or not physicalism is true (Crane, 2001). We may take ‘facts’ to be what either Jackson or Papineau take them to be, but either way, the knowledge argument still fails to successfully refute physicalism.
Crane, T. Elements of Mind: An Introduction to the Philosophy of Mind, Oxford: Oxford University Press, (2001).
Jackson, F. “What Mary Didn’t Know”, (1986), published in [NC] The Nature of Consciousness: Philosophical Debates, edited by Block, N., Flanagan, O. and Guzeldere, G. London: A Bradford Book, The MIT Press, (1997).
Lewis, D. “What Experience Teaches”, (1990), published in [NC] The Nature of Consciousness: Philosophical Debates, edited by Block, N., Flanagan, O. and Guzeldere, G. London: A Bradford Book, The MIT Press, (1997).
Loar, B. “Phenomenal states”, (1990), published in The [NC] Nature of Consciousness: Philosophical Debates, edited by Block, N., Flanagan, O. and Guzeldere, G, London: A Bradford Book, The MIT Press, (1997).
Nagel, T. “What Is It Like to Be a Bat?”, (1974), published in [NC] The Nature of Consciousness: Philosophical Debates, edited by Block, N., Flanagan, O. and Guzeldere, G. London: A Bradford Book, The MIT Press, (1997).
Nida-Rumelin, M. “Qualia: The Knowledge Argument”, published in Stanford Encyclopedia of Philosophy, website: Qualia: the Knowledge Argument , (2002).
Papineau, D. Thinking about Consciousness, Oxford: Clarendon Press, (2002).
Van Gulick, R. “Understanding the Phenomenal Mind: Are We All Just Armadillos? Part 1: Phenomenal Knowledge and Explanatory Gaps”, (1993), published in [NC] The Nature of Consciousness: Philosophical Debates, edited by Block, N., Flanagan, O. and Guzeldere, G. London: A Bradford Book, The MIT Press, (1997).
(1) Jackson, F. (1986), “What Mary Didn’t Know”, published in The Nature of Consciousness (NC), (1997), p. 567.
(2)Jackson, F. ibid, p. 567.
(3)Jackson, F. ibid, p. 567.
(4)Nagel, T. (1974), “What is it like to be a bat?” published in NC, ibid, p. 519.
(5)Lewis, D. (1990), “What Experience Teaches”, published in NC, ibid, p. 579.
(6)Lewis, D. ibid, p. 593.
(7)Papineau, D. (2002), Thinking About Consciousness, p. 62.
(8) Papineau, D. ibid, pp. 50-51.
(9) Loar, B. (1990), “Phenomenal States”, published in NC, ibid, p. 601.
(10) Papineau, D. ibid, p. 59.
(11) Crane, T. (2001), Elements of Mind: An Introduction to the Philosophy of Mind, p. 97.
(12) Crane, T. ibid, p. 99.
This paper was originally a Pre-Submission Essay for the 2009/10 BA Philosophy of Mind Paper, King’s College London, for part of the BA in Philosophy
Copyright © Alexander Rikowski, November 2010
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