Win,
The puppy first. No one claims that a puppy is logically entailed by all the physical facts about a puppy. People do claim that the experience of seeing red is logically entailed by all the physical facts about seeing red.
The knowledge of what it is like to see red is
not logically entailed by the physical facts about the knowledge of what it is like to see red. That is the point.
When we say that the experience is logically entailed by the physical facts about seeing red, we simply mean that the physical process of seeing red logically implies the existence of the experience of seeing red. This does not in any way mean that reading those facts from a book (which is simply a description of the process of seeing red) is going to produce the experience, or the memory of having had the experience.
OK. The knowledge part now. If you know all the physical facts about seeing red, then necessarily you know what it's like to experience red, if experiencing red is a physical fact.
Experiencing red is not a physical fact. It is a physical process. You can know all the physical facts about that process, but this is not the same as actually having the process occur in your brain.
Either you know it by virtue of knowing all the physical facts (and materialism is true), you don't it even though you know all the physical facts (and materialism is false) or the experience of seeing red doesn't contain any information, that is to say, isn't a fact that you can know.
The fact that you know all the physical facts does not imply that you know what it is like to see red. Saying that you know all the physical facts simply means that you have a complete description of the physical brain state that corresponds to you knowing what it is like to see red. It does not equate to you actually possessing that brain state.
Memories are physical, yes. The experience of memories isn't.
But we aren't talking about experience of memories here. We are talking about the memories. Presumably, even under your brand of Dualism, if we were to alter Mary's brain state so that she possessed the memory of having seen red, she would then know what it is like to see red, because she would experience that memory. Under Physicalism, the situation is the same, except that it is also her brain which experiences the memory, rather than something else. The effect is the same though. Either way the knowledge of what it is like to see red is a physical memory, located in the brain. Simply reading all the physical facts about that brain state is not going to cause that brain state to appear in her brain, which is what the Mary experiment is implying should be expected to happen.
From my position, information has a dual quality. The information about the content of qualia isn't physical information, it's phenomenal information. It isn't "contained" in our brains, as it were.
That's fine. The thought experiment is presented within the framework of physicalism, which holds that it is the brain that does the experiencing. The point is that if we accept the premise that the knowledge of what it is like to see red is a physical structure in the brain, then we cannot claim that knowing all of the physical facts about that physical structure is going to cause the physical structure to appear. Thus the argument that physicalism implies that Mary should be able to know what it is like to see red, simply by knowing all the physical facts about, is not valid.
Now, I guess we could ask, what would happen with p-zombie Mary. Emerging from her black and white room, light of the right wavelength will hit zombie Mary's eyes, causing signals to travel along her optical nerves to her geniculate bodies, thence to her visual cortex. New patterns, never before existing in zombie Mary's brain, will cause her to remark, "I can now see red." Those same patterns will create, or perhaps better, are in part, the false belief that she has had the experience of seeing red.
In real Mary, however, those patterns will be accompanied by experience, and the phenomenal information contained in the experience of seeing red is what is not logically entailed by all the physical facts.
Under your brand of Dualism, sure. But not under Physicalism.
You bring up a good point, though. Here is a question for both you and Rusty (since you are both advocating very different brands of dualism).
Imagine that we make a perfect physical copy of Mary. This copy is physically identical to Mary in every way. Several questions:
1) Do you believe this copy would be a p-zombie, or would it possess consciousness?
2) If she does have consciousness, then would she know what it is like to see, or hear, or any of the other things that Mary knows, but which the copy has not yet experienced?
3) If she does know what these things are like, even though she has never had the experiences, doesn't that imply that the knowledge of those experiences (not necessarily the experiences themselves, or the experiences of the memories) is purely physical?
I would assert that under physicalism, the answers would be:
1) She would possess consciousness.
2) She would know what all those things are like.
3) The knowledge of what those things are like is physically stored in her brain.
I would say that this is all that physicalism requires. It does not require that Mary knowing all the physical facts about seeing red, will cause Mary to actually possess the knowledge of what it is like to see red.
Another way to look at it is this. The knowledge of what it is like to see red is
not a physical fact about seeing red. Facts are just information. Knowledge is more than just information. Knowledge is a physical state in the brain. It is a physical representation of information.
There are, in fact, physical facts about the
knowledge of what it is like to see red. Mary could have those facts as well, but knowing those facts is not the same as having the knowledge, just as having all the facts about a puppy is not the same as having the puppy.
Dr. Stupid