Since there's a many-to-one mapping between physical states and temperatures, am I a temperature dualist? Would it be any less dualist to define a one-to-one mapping between physical states of glasses of water and really long strings? (You can assume that I insist that temperature and really long strings are real.)
The ontological status of temperature can be investigated by examining a simple ontology where it can be defined exactly, like an ideal gas in a box where the "atoms" interact only through perfectly elastic collisions. In such a situation, the momentum of an individual atom is an exact property with causal relevance. We can construct all sorts of exact composite properties by algebraically combining the momenta, e.g. "the square of the momentum of atom A minus the square root of the momentum of atom B", which I'll call property Z. But probably we don't want to say that property Z exists, in the way that the momentum-property does. The facts about property Z are really just arithmetic facts, facts about the numbers which happen to be the momenta of atoms A and B, and the other numbers they give rise to when combined. Property Z isn't playing a causal role in the physics, but the momentum property does.
Now, what about temperature? It has an exact definition: the average kinetic energy of an atom. But is it like "property" Z, or like the property of momentum? I think one has to say it's like property Z - it is a quantitative construct without causal power. It is true that if we know the temperature, we can often make predictions about the gas. But this predictive power appears to arise from logical relations between constructed meta-properties, and not because "temperature" is a physical cause. It's conceptually much closer than property Z to the level of real causes, but when you say that the temperature caused something, it's ultimately always a shorthand for what really happened.
When we apply all this to coarse-grained computational states, and their identification with mental states, I actually find myself making, not the argument that I intended (about many-to-one mappings), but another one, an argument against the validity of such an identification, even if it is conceived dualistically. It's the familiar observation that the mental states become epiphenomenal and not actually causally responsible for anything. Unless one is willing to explicitly advocate epiphenomenalism, then mental states must be regarded as causes. But if they are just a shorthand for complicated physical details, like temperature, then they are not causes of anything.
So: if you were to insist that temperature is a fundamental physical cause and not just a shorthand for microphysical complexities, then you would not only be a dualist, you would be saying something in contradiction with the causal model of the world offered by physics. It would be a version of phlogiston theory.
As for the "one-to-one mapping between physical states of glasses of water and really long strings" - I assume those are symbol-strings, not super-strings? Anyway, the existence of a one-to-one mapping is a necessary but not a sufficient condition for a proposed identity statement to be plausible. If you're saying that a physical glass of water really is a string of symbols, you'd be bringing up a whole other class of ontological mistakes that we haven't touched on so far, but which is increasingly endemic in computer-science metaphysics, namely the attempt to treat signs and symbols as ontologically fundamental.
It seems like we can cash out the statement "It appears to X that Y" as a fact about an agent X that builds models of the world which have the property Y.
I actually disagree with this, but thanks for highlighting the idea. The proposed reduction of "appearance" to "modeling" is one of the most common ways in which consciousness is reduced to computation. As a symptom of ontological error, it really deserves a diagnosis more precise than I can provide. But essentially, in such an interpretation, the ontological problem of appearance is just being ignored or thrown out, and all attention directed towards a functionally defined notion of representation; and then this throwing-out of the problem is passed off as an account of what appearance is.
Every appearance has an existence. It's one of the intriguing pseudo-paradoxes of consciousness that you can see something which isn't there. That ought to be a contradiction, but what it really means is that there is an appearance in your consciousness which does not correspond to something existing outside of your consciousness. Appearances do exist even when what they indicate does not exist. This is the proof (if such were needed) that appearances do exist. And there is no account of their existential character in a discourse which just talks about an agent's modeling of the world.
It appears to the brain I am talking to that qualia exist. It appears to the brain that is me that qualia exist. Yet this is not any evidence of the existence of qualia.
You are just sabotaging your own ability to think about consciousness, by inventing reasons to ignore appearances.
Facts about your phenomenology are facts about your programming!
No...
If you can type them into a computer, they must have a physical cause tracing back through your fingers, up a nerve, and through your brain.
Those are facts about my ability to communicate my phenomenology.
What's more interesting to think about is the nature of reflective self-awareness. If I'm able to say that I'm seeing , it's only because, a few steps back, I'm able to "see" that I'm seeing ; there's reflective awareness within consciousness of consciousness. There's a causal structure there, but there's also a non-causal ontological structure, some form of intentionality. It's this non-causal constitutive structure of consciousness which gets passed by in the computational account of reflection. The sequence of conscious states is a causally connected sequence of intentional states, and intentionality, like qualia, is one of the things that is missing in the standard physical ontology.
There is no rule in science that says that large-scale quantum entanglement makes this behavior more or less likely, so there is no evidence for large-scale quantum entanglement.
The appeal to quantum entanglement is meant to make possible an explanation of the ontology of mind revealed by phenomenology, it's not meant to explain how we are subsequently able to think about it and talk about it, though of course it all has to be connected.
My point is that the evidence for consciousness, that various humans such as myself and you believe that they are conscious, can be cashed out as a statement about computation, and computation and consciousness are orthogonal, so we have no evidence for consciousness.
Once again, appearance is being neglected in this passage, this time in favor of belief. To admit that something appears is necessarily to give it some kind of existential status.
B: "What are the properties of ontologically fundamental love?"
A: "[The equations that define the standard model of quantum mechanics]"
The word "love" already has a meaning, which is not exactly easy to map onto the proposed definition. But in any case, love also has a subjective appearance, which is different to the subjective appearance of hate, and this is why the experience of hate can falsify the theory that only love exists.
I'm a reductive materialist for statements - I don't see the problem with reading statements about consciousness as statements about quarks.
Intentionality, qualia, and the unity of consciousness; none of those things exist in the world of quarks as point particles in space.
Ontologically I suppose I'm an eliminative materialist.
The opposite sort of error to religion. In religion, you believe in something that doesn't exist. Here, you don't believe in something that does exist.
The central point about the temperature example is that facts about which properties really exist and which are just combinations of others are mostly, if not entirely, epiphenomenal. For instance, we can store the momenta of the particles, or their masses and velocities. There are many invertible functions we could apply to phase space, some of which would keep the calculations simple and some of which would not, but it's very unclear, and for most purposes irrelevant, which is the real one.
So when you say that X is/isn't ontologically fundamental, you ar...
...at least not if you accept a certain line of anthropic argument.
Thomas Nagel famously challenged the philosophical world to come to terms with qualia in his essay "What is it Like to Be a Bat?". Bats, with sensory systems so completely different from those of humans, must have exotic bat qualia that we could never imagine. Even if we deduce all the physical principles behind echolocation, even if we could specify the movement of every atom in a bat's senses and nervous system that represents its knowledge of where an echolocated insect is, we still have no idea what it's like to feel a subjective echolocation quale.
Anthropic reasoning is the idea that you can reason conditioning on your own existence. For example, the Doomsday Argument says that you would be more likely to exist in the present day if the overall number of future humans was medium-sized instead of humongous, therefore since you exist in the present day, there must be only a medium-sized number of future humans, and the apocalypse must be nigh, for values of nigh equal to "within a few hundred years or so".
The Buddhists have a parable to motivate young seekers after enlightenment. They say - there are zillions upon zillions of insects, trillions upon trillions of lesser animals, and only a relative handful of human beings. For a reincarnating soul to be born as a human being, then, is a rare and precious gift, and an opportunity that should be seized with great enthusiasm, as it will be endless eons before it comes around again.
Whatever one thinks of reincarnation, the parable raises an interesting point. Considering the vast number of non-human animals compared to humans, the probability of being a human is vanishingly low. Therefore, chances are that if I could be an animal, I would be. This makes a strong anthropic argument that it is impossible for me to be an animal.
The phrase "for me to be an animal" may sound nonsensical, but "why am I me, rather than an animal?" is not obviously sillier than "why am I me, rather than a person from the far future?". If the doomsday argument is sufficient to prove that some catastrophe is preventing me from being one of a trillion spacefaring citizens of the colonized galaxy, this argument hints that something is preventing me from being one of a trillion bats or birds or insects.
And this could be that animals lack subjective experience. This would explain quite nicely why I'm not an animal: because you can't be an animal, any more than you can be a toaster. So Thomas Nagel can stop worrying about what it's like to be a bat, and the rest of us can eat veal and foie gras guilt-free.
But before we break out the dolphin sausages - this is a pretty weird conclusion. It suggests there's a qualitative and discontinuous difference between the nervous system of other beings and our own, not just in what capacities they have but in the way they cause experience. It should make dualists a little bit happier and materialists a little bit more confused (though it's far from knockout proof of either).
The most significant objection I can think of is that it is significant not that we are beings with experiences, but that we know we are beings with experiences and can self-identify as conscious - a distinction that applies only to humans and maybe to some species like apes and dolphins who are rare enough not to throw off the numbers. But why can't we use the reference class of conscious beings if we want to? One might as well consider it significant only that we are beings who make anthropic arguments, and imagine there will be no Doomsday but that anthropic reasoning will fall out of favor in a few decades.
But I still don't fully accept this argument, and I'd be pretty happy if someone could find a more substantial flaw in it.