Dennet, being a materialist, reads the question in this manner and simply agrees that Mary will not be surprised, since materialism is true.
Then he is quite simply wrong. Knowledge can never be fully separated from its representation, just as one can never quite untangle a mind from the body it wears. ;-)
This conclusion is a requirement of actual materialism, since if you’re truly materialist, you know that knowledge can’t exist apart from a representation. Our applying the same label to two different representations is our own confusion, not one that exists in reality.
Reading the thought experiment as a logic problem, one should accept the conflation of the two putative mental states you’ve identified (calling them both ‘knowing’)
If you start from a nonsensical premise, you can prove just about anything. In this case, the premise is begging a question: you can only conflate the relevant types of knowledge under discussion, if you already assume that knowledge is independent of physical form… an assumption that any sufficiently advanced materialism should hold false.
This conclusion is a requirement of actual materialism, since if you’re truly materialist, you know that knowledge can’t exist apart from a representation. Our applying the same label to two different representations is our own confusion, not one that exists in reality.
It really doesn’t have to be a confusion though. We apply the label ‘fruit’ to both apples and oranges—that doesn’t mean we’re confused just because apples are different from oranges.
Then he is quite simply wrong. Knowledge can never be fully separated from its representation, just as one can never quite untangle a mind from the body it wears. ;-)
I don’t think either I or Dennett made that claim. You don’t need it for the premise of the thought experiment. You just need to understand that any mental state is going to be represented using some configuration of brain-stuff...
According to the thought experiment, Mary “knows” everything physical about the color red, and that will include any relevant sense of the word “knows”. And so if the only way to “know” what experiencing the color red feels like is to have the neurons fire that actually fire when seeing red, then she’s had those neurons fire. It could be by surgery, or hallucination, or divine intervention—it doesn’t matter, it was given as a premise in the thought experiment that she knows what that’s like.
One way to make such a Mary would be to determine what the configuration of neurons in Mary’s brain would be after experiencing red, then surgically alter her brain to have that configuration. The premise of the thought experiment is that she has this information, and so if that’s the only way she could have gotten it, then that’s what happened.
And so if the only way to “know” what experiencing the color red feels like is to have the neurons fire that actually fire when seeing red, then she’s had those neurons fire.
This is going way beyond what I’d consider to be a reasonable reading of the intent of the thought experiment. If you’re allowed to expand the meaning of the non-specific phrase “knows everything physical” to include an exact analogue of subjective experience, then the original meaning of the thought experiment goes right out the window.
My reading of this entire exchange has thomblake and JamesAndrix repeatedly begging the question in every comment, taking great license with the intent of the thought experiment, while pjeby keeps trying to ground the discussion in reality by pinning down what brain states are being compared. So the exchange as a whole is mildly illuminating, but only because the former are acting as foils for the latter.
You can’t keep arguing this on the verbal/definitional level. The meat is in the bit about brain states.
Call the set of brain states that enable Mary to recall the subjective experience of red, Set R. If seeing red for the first time imparts an ability to recall redness that was not there before, then as far as I’m concerned that’s what’s meant by “surprise”.
We know that seeing something red with her eyes puts her brain into a state that is in Set R. The question is whether there is a body of knowledge, this irritatingly ill-defined concept of “all ‘physical’ knowledge about red”, that places her brain into a state in Set R. It is a useless mental exercise to divorce this from how human brains and eyes actually work. Either a brain can be put into Set R without experiencing red, or it can’t. It seems very unlikely that descriptive knowledge could accomplish this. If you’re just going to toss direct neuronal manipulation in there with descriptive knowledge, then the whole thought experiment becomes a farce.
Then he is quite simply wrong. Knowledge can never be fully separated from its representation, just as one can never quite untangle a mind from the body it wears. ;-)
This conclusion is a requirement of actual materialism, since if you’re truly materialist, you know that knowledge can’t exist apart from a representation. Our applying the same label to two different representations is our own confusion, not one that exists in reality.
If you start from a nonsensical premise, you can prove just about anything. In this case, the premise is begging a question: you can only conflate the relevant types of knowledge under discussion, if you already assume that knowledge is independent of physical form… an assumption that any sufficiently advanced materialism should hold false.
It really doesn’t have to be a confusion though. We apply the label ‘fruit’ to both apples and oranges—that doesn’t mean we’re confused just because apples are different from oranges.
I don’t think either I or Dennett made that claim. You don’t need it for the premise of the thought experiment. You just need to understand that any mental state is going to be represented using some configuration of brain-stuff...
According to the thought experiment, Mary “knows” everything physical about the color red, and that will include any relevant sense of the word “knows”. And so if the only way to “know” what experiencing the color red feels like is to have the neurons fire that actually fire when seeing red, then she’s had those neurons fire. It could be by surgery, or hallucination, or divine intervention—it doesn’t matter, it was given as a premise in the thought experiment that she knows what that’s like.
One way to make such a Mary would be to determine what the configuration of neurons in Mary’s brain would be after experiencing red, then surgically alter her brain to have that configuration. The premise of the thought experiment is that she has this information, and so if that’s the only way she could have gotten it, then that’s what happened.
This is going way beyond what I’d consider to be a reasonable reading of the intent of the thought experiment. If you’re allowed to expand the meaning of the non-specific phrase “knows everything physical” to include an exact analogue of subjective experience, then the original meaning of the thought experiment goes right out the window.
My reading of this entire exchange has thomblake and JamesAndrix repeatedly begging the question in every comment, taking great license with the intent of the thought experiment, while pjeby keeps trying to ground the discussion in reality by pinning down what brain states are being compared. So the exchange as a whole is mildly illuminating, but only because the former are acting as foils for the latter.
You can’t keep arguing this on the verbal/definitional level. The meat is in the bit about brain states.
Call the set of brain states that enable Mary to recall the subjective experience of red, Set R. If seeing red for the first time imparts an ability to recall redness that was not there before, then as far as I’m concerned that’s what’s meant by “surprise”.
We know that seeing something red with her eyes puts her brain into a state that is in Set R. The question is whether there is a body of knowledge, this irritatingly ill-defined concept of “all ‘physical’ knowledge about red”, that places her brain into a state in Set R. It is a useless mental exercise to divorce this from how human brains and eyes actually work. Either a brain can be put into Set R without experiencing red, or it can’t. It seems very unlikely that descriptive knowledge could accomplish this. If you’re just going to toss direct neuronal manipulation in there with descriptive knowledge, then the whole thought experiment becomes a farce.