The big problem I have with Qualia is how do you tell a qualia zombie from someone whom can experience qualia?
Hi,
Assuming a zombie could in fact exist, you could not differentiate 'real' from 'artificial' for the same reason a subjective experience is not open to objective scrutiny. The reality of Qualia is not a scientific question but a metaphysical one. Such things by definition would be non-physical and subjective, and therefore not open to the direct type of experimental scrutiny employed in science. Their existence can only be inferred and not demonstrated objectively.
Science is not concerned with absolute truths or metaphysical speculations but is strictly a utilitarian tool to explain, predict, and model phenomenon directly or indirectly available to the senses. The goal of science is to gather data through observations and then proceed from there to construct a working theory that is useful in modeling and predicting future observations or infer prior or future states in an arbitrary system.
On Philosophical grounds, the ongoing epistemological challenge when discussing the neurosciences is how to recognize when one has fallen prey to the fallacy of association. Through observation and experiment we can certainly associate the subjective appearance of mental states and conscious sensations with the activity of the neurosystem; however, (If A then B) does not mean (A=B). Certainly, the activity and patterns of neurons within the brain equates to the manifestation of an experience, it does not however equate to Qualia being equal to a neuron or pattern of neurons. Just as we can easily observe that the behavior and existence of neurons produce a Qualia,,we can easily observe that gravity produces acceleration. In a Newtonian sense, it would be incorrect, however, to say acceleration=gravity. In this view, neuronal activity is simply the Modus Operandi of the manifestation of Qualia.
I tend to view Consciousness and Qualia as emergent phenomenon that are as fundamental to nature as is the phenomenon of gravity or electromagnetism. Of course, how well one accepts the arguments for or against the existence of Qualia depends on one's philosophical preferences. The subject is much more complex than it appears at first glance and delves deeply into the nature of Causation, Causal Necessity, Law, the definition of Subjective and Objective, and our theories of knowledge.