An interesting consequence of generalised attributions of human exceptionalism is that we tend to automatically believe that all intelligence, all value and all experience exist (and persist) in this diminutive cranial cavity we inhabit. Cogito ergo something is definitely going on between our ears but there is a deep and irreducible mystery at work (i.e. David Chalmers “Hard Problem” of consciousness).
At a level of holistic systems analysis it becomes clear that, just as with the missing “secret sauce” in iterative technical aspirations to Artificial General Intelligence, there is something peculiar, elusive and enigmatic dwelling in the distributed, global and integrated or unified properties of material (as much as logical) systems. Identifying this unifying principle is not difficult – given a little lateral thought – but represents a vast and intractable cognitive or linguistic and grammatical challenge for explanatory heuristics.
The unifying property of conscious systems occurs at a logical dimension that is constitutively unintelligible, but which can still be indirectly approached. Reductive, linear analysis of consciousness or intelligence (and its semantic, aesthetic overlay of experience) is irreducible to a brain because there is a hidden logical layer.