The progress of cognitive science over the last several decades has dispatched, with some confidence, what David Chalmers called 'the easy problems' of consciousness: the integration of information, the capacity for reportability, the differential attention to stimuli, the focus of awareness. These problems are not easy in any colloquial sense; their working out has required immense labour and is incomplete in many specifics. They are easy only in the technical sense that they are the kind of problem cognitive science knows how to address — problems specifying functional relations between input and behaviour, susceptible to the methods of computation, neuroscience, and experimental psychology.
The 'hard problem,' on Chalmers's distinction, is something else: not the relation of information processing to behaviour but the relation of information processing to experience — to what it is like, in the first person, to undergo the processing in question. Why should the integration of certain kinds of information feel like the redness of red, or the bite of pain, rather than proceed in the dark? The cognitive scientist's tools have proved well suited to the question how the integration occurs; they have proved less suited to the question why, given that it occurs, it is accompanied by anything at all.
Two large families of response have organised the subsequent literature. One denies that the hard problem is, on closer examination, a different problem at all; the appearance of an explanatory gap is, on this view, an artefact of how we presently conceptualise the phenomenon, and will dissolve once the right conceptual moves are made. The other accepts that the gap is real and locates it variously — in the special character of phenomenal consciousness, in the limits of our current physical theory, in the ineliminable role of the first-person perspective in any account of experience. Each family has internal disputes that often exceed its disputes with the other.
What survives, on the most careful reading, is less a settled answer than a clarified disagreement. The hard problem, if it is real, sits at a place where the methods of empirical investigation begin to lose their accustomed grip; if it is an illusion, the illusion is robust enough that its dispelling has yet to be accomplished after several decades of patient effort. To call the question settled, in either direction, is to underestimate the difficulty of the underlying issue and the difficulty of even agreeing on what would count as a settlement of it.
It can be inferred from the passage that a philosopher who claims that the hard problem of consciousness 'will dissolve once the right conceptual moves are made' is most likely: