neurotransmitters/neuroarchitecture/physiological------------------------------>Qualia/inner experience
It's like there is some HIDDEN theater of inner experience that is always in the equation but is never explained away. — schopenhauer1
The Hard Problem, or explanatory gap, can only exist philosophically to the extent that you believe in the metaphysical constructs of both self and world, consciousness and matter. That is, hard dualism arises because the mind and the world are both being imagined in substance terms. They are both kinds of "stuff" - a material stuff and an immaterial stuff. And imagined this way, there seems an over-supply of stuffs making up the one reality. Also there seems no substantial connection - no causal link - between these two kinds of stuff. Being different in kind, how can either act on the other?
So the first step to tackling the Hard Problem is to start to deflate it. One can delve deeper into the notion of substance - as Aristotle and others did - to start to see "stuff" in terms of a systems causality. You can start to see all "stuff" as a process with a functional structure. The question then becomes whether what we call mind, and what we call world, turn out to have a common causal architecture, a common fundamental process.
The Peircean pansemiotic position is that they do. And that commonality of process is semiosis or the triadic sign relation. That involves the "dualism" we need to have anything actually happen - a separation (via the epistemic cut) of a causal realm of information and a causal realm of material dynamics. But semiosis also then accounts for the subsequent interaction of the two species of causality thus divided. Together they make a functional whole with a purpose.
From a scientific point of view, that global purpose is entropy dissipation - as described by the laws of thermodynamics. And that entropy dissipation is then evolutionary. It is shaped by the demand to always get better in terms of its structural organisation. Complexity and mindfulness must emerge if it can locally accelerate the Universe's telic desire for its Heat Death.
Or from a more philosophical point of view like Peirce (when he wasn't being a scientist taking a thermodynamic view), we can talk about existence as the universal growth of reasonableness. The Universe is "mindful" in the sense that it is always growing more fixed and habitual in its ways. The laws - like the laws of thermodynamics - are becoming ever more clearly expressed.
Anyway, the point is that the Hard Problem itself depends on a misplaced concreteness when talking about
both mind and matter. It is a hard problem because it is a dualised substance ontology.
Given that our starting point is simple experience, we need to realise that even our notion of "being a conscious being" is a social construct. It is a story we learn to tell to organise our experiences. We reify both the world, and our selves, then wonder why we have this explanatory gap.
Peircean metaphysics in particular seeks to wind all this assumed ontology back to basics. It wants to categorise experience differently. Indeed it begins with the question about the very mechanism by which experience gets categorised - how reasoning might operate as the most general and universal process.
That eventually leads to semiosis with its triadic structure of interpretation, sign and invariance; its dichotomy of information and matter, its ontic foundation in the notion of vagueness, Firstness or Apeiron.
And science is catching up. Semiosis can now be measured. At the physical level, the Planck scale defines the common unit for information and matter. The material cost of one bit of information - or a physical degree of freedom - is precisely defined in a way we can convert between our material descriptions of nature and our information theoretic ones. We can speak of entropy equivalently as either a quantity of material events or a quantity of informational uncertainty. It is part of the maths now.
What is a major new discovery in biophysics is that the same looks true of biosemiosis. There is a particular physical scale - the quasi-classical realm of the nanoscale - where material events and informational uncertainy become intercovertable. They can be quantified in a common coin.
It might have been thought biology was going to be messy in its underpinnings. It would be hard to define a level where physics and chemistry stops, biological organisation gets started. But instead, an actual scale of being has been identified where biological information suddenly kicks in as a thing which could regulate living material processes - all the tiny genetically-coded actions that structure a flow of metabolism and organism building.
So life has a hard lower limit, just like physics has.
Next step might be to find the same is true of brains and neural coding mechanisms. There may be some characteristic scale where neuro-semiosis suddenly kicks in as a hard fact of nature. Or maybe not. Maybe the biophysical limit - the action down there at the nano level of molecular machines - is where "mindfulness" kicks in already. This is a question so new and open, that it hasn't really been considered.
But whatever. The Hard Problem has its bite mostly because folk are used to thinking of existence in terms of a causally disconnected substance dualism. The truck has been driven all the way up a philosophical cul-de-sac and has got stuck.
But science is quite capable of talking a functional process view of existence. And it is already doing this with physics.
The Universe is a dissipative structure doing the second law's bidding. Classical reality is the organisation that emerges out of a more fundamental quantum vagueness or indeterminism. There is a basic "duality" of description anchored by the Planck scale. Observers and observables may seem divided by the quantum "hard problem" of the measurement issue, but now we can in fact quantify both sides of this divide in information theoretic terms. We can unite the divided in terms of holographic horizons, thermal decoherence, entropic forces, and other new-fangled physical conceptions which embed their observers pansemiotically.
Now biophysics has started to find its own ground zero for uniting it and bit, material dynamics and informational constraint. The laboratory equipment to observe cellular machinery on the nanoscale has only been around a decade, so this is all extremely new. And it might take another 10 years for the import of the discovery to become widely recognised.
So we are talking about the difference between a dead philosophical position - substance dualism - and a fast moving scientific project - pansemiosis.
And pansemiosis isn't about solving the hard problem by showing how "consciousness works". That would be to accept the goalposts of a dead philosophy. It is about reconceiving the metaphysical constructs which we would use to organise our experience so that we are no longer dazzled by either the "illusion" of the material world, or the aware mind. As we learn to think differently - existence understood as a common functional process, semiosis - then the old problems that obsessed us will slip away.
We might still have explanatory problems, but they would at least be different ones. Which would make a refreshing change.