Always learning. Always wrong.
Escaping Mary’s Room
As soon as a philosopher begins talking about mental states as though they are fundamental or uniquely important things and not convenient abstractions for talking about particles bopping around in a particular way, you should know you’re in trouble. It’s an unfortunately common variety of motivated thinking to come up with a grand theory of the universe that just happens to have the theorizer in the center; be wary.
While this is good advice, it is not really a counter-argument. There are arguments against dualisms in general, but I will instead be focusing on specific errors in these next couple posts, on the grounds that dealing with them is both more straightforward and more entertaining.
So. Mary’s Room is a thought experiment first formulated by Frank Jackson as follows:
Mary is a brilliant scientist who 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 cords and expulsion of air from the lungs that results in the uttering of the sentence ‘The sky is blue’. [...] 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?
(Via Wikipedia)
Or, to put it another way, Mary is a person who has complete and exhaustive physical knowledge of everything about color and how humans perceive it, but who has never experienced it herself. If she then experiences it, can she be said to have acquired some (non-physical) knowledge she didn’t previously possess?
This thought experiment has been the subject of a great deal of debate among philosophers of mind. Which is silly, because the answer is trivially and obviously no.
Mary’s complete and exhaustive physical knowledge of human color perception must include knowledge of how her own brain experiences colors. The human brain deals with experiential knowledge as well as explicit verbal knowledge; I know how to ride a bike, but this has nothing to do with my knowledge of gyroscopes and angular momentum. But this does not and should not lead us to say that my knowledge of how to ride a bike is somehow non-physical. It is merely represented and processed differently by my brain.
And yet somehow people have been arguing about this (usually badly) for more than 20 years. Five or ten minutes should really be enough. Let’s move on.
Tomorrow: I do not understand Chinese.
| This entry was posted by WrongBot on March 3, 2011 at 11:16 pm, and is filed under Problems in Philosophy. Follow any responses to this post through RSS 2.0. You can leave a response or trackback from your own site. |
about 11 months ago
I think this thought experiment is flawed.
Mary learns something because she didn’t have complete and exhaustive physical knowledge: having such knowledge would mean she has seen red. She can’t simultaneously have “all the knowledge” and have never seen red. Her visual system perceiving red is a physical form of information that she is stated not to have.
Someone’s posted something similar on LessWrong:
http://lesswrong.com/lw/168/esrs_new_take_on_qualia/1262
about 11 months ago
“Mary’s complete and exhaustive physical knowledge of human color perception must include knowledge of how her own brain experiences colors.”
The thought experiment implies that her knowledge is entirely non-experiential so I’d say the correct answer is “yes.” This doesn’t mean that there’s something non-physical going on but really just reflects what the limitations are on specific knowledge acquiring abilities. All that Mary would know is that the brain interprets different wavelengths in such a way that it can tell the difference between them. She’ll also might know the names for these differences. But I don’t see any way for her to know what occurs from a first person perspective when the brain interprets specific wavelengths.
about 11 months ago
It should say Frank Jackson not Johnson.
Interestingly, Jackson no longer believes that this thought experiment is evidence for dualism. He says here, “So what is the before and after story about Mary? If feel is a matter of immediacy, inextricability, and richness of representational content, and the right kind of functional role, the difference is that, after her release, Mary has representational states with all those properties. If she makes the mistake of conflating intensional properties with instantiated properties, she will think that she has learnt something new about how things are, but she’ll be wrong. Rather, she is in a new kind of representational state from those she was in before. And what is it to know what it is like to be in that kind of state? Presumably, it is to be able to recognise, remember and imagine the state.”
His points are that knowing what it is like to see red is only being able to recognize remember and imagine a certain representational state, and this is not knowledge about any real property about the world, but is just an ability.
about 11 months ago
Eeep, thanks for the correction. I’ve edited the post.
Thanks also for the update on Jackson; I like his spin on it.
about 11 months ago
I’ve read Automaton’s comment several times, but to my shame, I don’t understand Jackson’s point. Could you make a bit more explicit, please?
about 11 months ago
My comment might have been unclear because I was trying to summarize the punchline of Jackson’s paper, which is long and covers a lot of ground, not all of which I completely understand. I’ll try to explain in more detail.
The purpose of this paper is for Jackson to explain why he no longer believes the Mary’s Room thought experiment he devised is evidence against physicalism and to counter some common objections others have made to the thought experiment.
He believes that the only way to reconcile Mary’s Room with physicalism is with a representational theory of consciousness. These theories say roughly that a conscious state is an intentional state, meaning a state which represents an object, and that there is nothing to conscious experience beyond a representational state. Specifically he rejects the sense-datum theory he previously held which says “experiences are composed of an act of awareness directed to an object or sense datum which bears the qualities” .
Before Jackson came to believe a representational theory of consciousness, he believed a sense-datum theory, so he believed the “datum” which Mary would be directly aware of when seeing red had to be non-physical. I’m unclear on his exact logic for why this is the case, and why the ability response given by WrongBot and others would fail even if the sense-datum theory was correct. In any case he goes on to say that in a representational theory, there is no thing that has the property of “redness” as experienced by conscious beings, but that the subjective experience of “red” is nothing more than a representational state. He believes that “red” is in some sense only an illusion, since nothing has the property of “redness” (hence the title of his paper). Given this, he no longer has qualms about saying that “knowing what it is like to see red” is simply the ability to recognize, remember and imagine the representational state.
The first part of Jackson’s quote from above about feel being a matter of “immediacy, inextricability, and richness of representational content” is referencing his attempts earlier in the paper to explain why some representational states have a conscious feel while others don’t. He thinks that immediacy, inextricability and richness of content are the important factors in that. For example you can think about a ball without having any particular conscious experience of a ball, but if you visualize a ball you have to imagine it having a certain color, size, location etc. and these properties can’t be removed from the visualization (you can’t imagine a colorless ball).
about 11 months ago
Thank you Automaton. It’s clearer now.
about 10 months ago
I just wanted to say that the first sentence of this post is gold. It nicely explains what’s wrong with whole categories of philosophy, and especially theistic arguments. I’ve quoted it again and again.