As I understood it, Mary is, in the thought experiment, supposed to be very nearly omniscient—she knows EVERY PHYSICAL FACT about color and human perception of color.
My question is whether she’s allowed (before exiting the room) to wire her brain up to a machine that stimulates her neurons exactly as if there was a red thing in front of her.
Would you agree that if she were allowed to use such a machine, then she would know which response her brain in fact would have?
Yes, I do, but I think that turns it into an unhelpful question. If she already knows enough to stimulate her neurons to generate what it feels like “exactly as if there was a red thing in front of her”, then of course she won’t learn anything from seeing red. But knowing enough to do that raises the question of how she could know she’s generating the right feeling, which just regresses to the original dilemma. It’s like saying, “If Mary knows everything, does she know a subset of everything?”
I thought the point of the scenario was to ask if Mary learns anything from seeing red if, before that, she received sensory data in all modes except color sight—that is, she could feel or smell or even see black and white images.
The above reformulation is still fair because, for example, she can run simulations of other people that have information about their reactions to red, and information about her own brain, and she can extrapolate to her internal experience. But I would still say that when she sees red, she resolves residual uncertainty, for example, about which of several branching Marys she is.
As I understand it, the point of the scenario is intended to be an argument against physicalism. Qualia are claimed to be nonphysical, because Mary knew “every physical fact” about color and human color perception, but still (it is claimed) learned something when she saw red for the first time.
Dennett, if I undersand him correctly, argues that the “knowing every physical fact” is a very strong hypothesis, which the exposition of the scenario doesn’t pay enough attention to. With so much information and comprehension, Mary is not very much like a human; our intuition that she would say “wow” is not trustworthy.
In particular, I don’t think that we actually disagree—your posts seem to come from a physicalist, rather than dualist, conception of the world.
As I understood it, Mary is, in the thought experiment, supposed to be very nearly omniscient—she knows EVERY PHYSICAL FACT about color and human perception of color.
My question is whether she’s allowed (before exiting the room) to wire her brain up to a machine that stimulates her neurons exactly as if there was a red thing in front of her.
Would you agree that if she were allowed to use such a machine, then she would know which response her brain in fact would have?
Yes, I do, but I think that turns it into an unhelpful question. If she already knows enough to stimulate her neurons to generate what it feels like “exactly as if there was a red thing in front of her”, then of course she won’t learn anything from seeing red. But knowing enough to do that raises the question of how she could know she’s generating the right feeling, which just regresses to the original dilemma. It’s like saying, “If Mary knows everything, does she know a subset of everything?”
I thought the point of the scenario was to ask if Mary learns anything from seeing red if, before that, she received sensory data in all modes except color sight—that is, she could feel or smell or even see black and white images.
The above reformulation is still fair because, for example, she can run simulations of other people that have information about their reactions to red, and information about her own brain, and she can extrapolate to her internal experience. But I would still say that when she sees red, she resolves residual uncertainty, for example, about which of several branching Marys she is.
As I understand it, the point of the scenario is intended to be an argument against physicalism. Qualia are claimed to be nonphysical, because Mary knew “every physical fact” about color and human color perception, but still (it is claimed) learned something when she saw red for the first time.
Dennett, if I undersand him correctly, argues that the “knowing every physical fact” is a very strong hypothesis, which the exposition of the scenario doesn’t pay enough attention to. With so much information and comprehension, Mary is not very much like a human; our intuition that she would say “wow” is not trustworthy.
In particular, I don’t think that we actually disagree—your posts seem to come from a physicalist, rather than dualist, conception of the world.