Ever since reading Douglas Hofstadter's Gödel, Escher, Bach as a teenager I've been fascinated by the idea that consciousness is an emergent property of physical systems. Roughly the claim is that consciousness is a physical property, but not one which can be reduced to lower-level physical properties of the sort described by biology, chemistry, and physics, etc. In particular, this view supports the idea that a human consciousness could be realized in a sufficiently advanced digital computer (although it does not imply that is possible to transfer an existing consciousness to a computer since that would additionally require that such a process preserves personal identity).
It seems like this idea is not taken very seriously among philosophers of mind who talk about the hard problem of consciousness and I'd like to know if there are some major arguments against it that I am missing.
Arguments like Searle's Chinese Room appear to convince many philosophers that the emergent property approach is a non-starter. However, I've never found the Chinese Room convincing. It relies on describing the situation in such a way that our attention is brought to the low-level functioning of the system (moving slips of paper around). When we view the system through this lens, we don't find anything that looks like qualia. However, the exact same is true if we look at the operation of a human being through a microscope. The emergent property theory of consciousness would say that only a higher-level view of the physical system can show us the relevant emergent property. If we try to adopt such a high-level of Chinese-room like scenarios (i.e., considering advance AGI systems) the intuitions start to become a lot less favourable to Searle's position.
The other argument I'm familiar with is Chalmers' zombie idea. I'm not familiar with all the details of his arguments so please let me know if I've missed something important. As I understand it, a strong zombie is one which is physically identical to a human but which lacks qualia. A weak zombie is one which is indistinguishable in terms of high-level behavior but differs in low-level physical states. Chalmers claims that a strong zombie is logically possible and bases some of his arguments on this claim. However, if it is true that in fact qualia are identical to emergent physical properties, then, assuming that "having qualia" is a rigid designator (see Kripke on necessary a posteriori or Putnam's "water is H2O"), strong zombies are logically impossible because they are based on an inconsistent hypothesis. If we assume that humans are conscious, then on the emergence view, human consciousness is logically identical to a high level property which is possessed by humans. Then the fact that strong zombies have all the physical properties of humans implies a fortiori they must possess the specific physical properties that in humans are identical to consciousness. By the logical law of identity, strong zombies must be conscious too, contradicting the other half of the strong zombie definition (this argument assumes that facts of logical identity are logically necessary).
If this is right, then only weak zombies remain as a challenge to the emergence view of consciousness. One way to construe the weak zombie view is to say that such a being displays all the high-level properties we identify as consciousness but lacks (by hypothesis) the low-level properties of all known conscious systems. By the emergence theory, there is no description that reduces the high-level physical properties, which are identical to consciousness, to low-level physical properties that are necessary and sufficient for consciousness. This is just what emergence implies, and it is compatible with both weak and strong theories of emergence. Therefore, it doesn't seem like weak zombies can even be defined rigorously if the emergence theory is true.
The only version of zombies that survives would be deceptive zombies. These are beings that in fact lack the high-level physical properties necessary for consciousness, but which nevertheless give off an illusory appearance of having those properties. We are all familiar with examples in the form of AI chatbots that could be taken as this sort of zombie. However, if we imagine that the deception is perfect and totally impenetrable no matter what type of further investigation we might do, then we are in the territory of general skeptical worries, analogous to Descartes' evil demon. It is always logically possible that our best efforts at gathering reliable evidence could fail due to some unforeseeable or gerrymandered epistemic setup. In the case of deceptive zombies we are imagining that despite all appearances of them having the relevant high-level physical properties, they still somehow lack them. Why would this present any specific issues for theories of consciousness that would not equally effect accounts of any type of emergent a posteriori knowledge? For example, it seems if we take deceptive zombies to be a problem, we at least have to take solipsism to be a major problem. Conversely, adopting a default and challenge response to skepticism in general, and other minds skepticism in particular, would be sufficient to render the deceptive zombie possibility epistemically irrelevant except in special cases.
Again, my question is, what I have a missed. I have a strong feeling that there must be some crucial arguments I've either not seen or not fully appreciated.