Thanks. To start, I question the value of trying to define consciousness as that already puts it in the class of a thing rather than a process. I don't see consciousness as anything fundamental in the world, just what it is like to be a really complex version of a modelling relation.
That doesn't mean I dismiss the problem of "raw feels" or qualia. It is just that I don't think that is the correct explanatory target. Once you know enough about how the brain executes any function, you can see why it has the particular qualitative character that it does. Mach bands is a good example.
But the question of "why any qualitative character at all - when perhaps there might be just zombiedom?" is the kind of query which already reifies awareness in an illegitimate way. It turns it from being the consequence of a process (a modelling of the world which prima facie ought to feel like something) to being a state of being, a kind of extra glow or ghost or spirit, that then appears to deserve an explanation in terms of being "a fundamental stuff or realm".
To think the Hard Problem actually makes sense is to have already concluded consciousness is an ontic "simple", against all the scientific evidence that it is what you get from an unbelievably complex and integrated world modelling process.
And this approach is familiar to any biologist. Folk used to believe that life must be the result of a ghost in the machine. Life had to be a simple, some kind of fundamental spirit or force of animation. But biology got to work and dispelled the mystery. The body is not exactly a machine. However once we see it as a semiotic relation between information and matter - genes and chemistry - then we can see we are talking about a self-creating process. Rather than life, we are talking about lively. Instead of seeking an explanation of what special thing makes inanimate flesh light up with "life", we understand that it is the unbelievably complex and integrated process that adequately accounts for the flesh being what we would then call "alive".
So that is why I take the approach I do. The metaphysics that worked to fully account for life should also continue on to account for mind. The Hard Problem - which is tied to a metaphysics of simples - just doesn't have the bite that people so easily presume.
So I am starting with the belief that awareness is the outcome of a certain species of systems complexity. And the way to explain that causally is to identify the essence of that complex process. What in general is the organisational trick that explains what the brain is doing in its now vastly elaborated way?
To answer that, one has to look to what metaphysics and science has to say about complex systems. Most of science, and even philosophy, is strictly reductionist. It breaks the complex world down into simples. Which is fine as part of the story, but also limited. Then there is a long tradition of holism or organicism. And that shows reality to be irreducibly complex. Even when things are made as simple as possible, they are still complex in terms of their essential structure of relations. Nothing is atomistic. Everything starts as already a process, some basic kind of relation.
One can start with Anaximander, the first true metaphysician. Apokrisis of course was his term for the "first process" - dichotomisation or "separating out". Then there is Aristotle with his four causes, his theory of hylomorphism, and the true start of systems thinking. Hegel and Kant got it. Then Peirce really managed to crystalise it. And finally the systems approach has become increasingly concrete and mathematically definite through the last century of scientific modelling.
So the basic trick of life and mind is that it is a particular kind of complex organisation - a modelling relation (as the mathematical biologist, Robert Rosen, defined it). Stan Salthe and Howard Pattee are then two of Rosen's circle who fleshed out a full understanding of what this means through the 70s and 80s under the general banner of what was hierarchy theory then. A connection got made to the new thermodynamics of dissipative structures (the follow-on from Prigogine's far-from-equilibrium open systems).
Salthe coined the idea of infodynamics. Pattee really sharpened things with his epistemic cut. And then this particular group of systems biologists heard about Peircean semiotics - which had pretty much been lost until the 1990s - and realised that they were basically recapitulating what Peirce had already said. So as a group they did the honourable thing and relabelled themselves bio-semioticians.
There were other allied groups around. Dozens of them. I was part of Salthe and Pattee's group - having looked around and found they were head and shoulders above the rest. But there were plenty of other important theoretical circles, like second order cybernetics, or generative neural nets, or complex adaptive systems, or dissipative structure theorists, or general system theorists, or .... well really, dozens and dozens.
So what is really the story is that there is a systems perspective. Instead of life or mind being ontic simples - animating spirits - they are understood in terms of a particular species of complexity. And the job is to seek explanations in those terms. Once you get that and start looking around, you find there are a whole range of people and groups who have been feeling the same elephant. They might all use different jargon. But they are arriving at the same kind of insights.
Again, this is only my perspective, but I find Peircean semiosis is the best way to zero in on the esssence of systems causality. It has a set of features I could list. And indeed I am always mentioning them.
But for now, in this thread, the key point is why I reject the usual demand of "answer the Hard Problem". Framing that as the crucial question is already to presume that the answer has the form "consciousness is an ontic simple, a substance". It gets to be like being asked "when did you stop beating your wife?".
The proper question we ought to be asking is what kind of fundamental system or process is a brain (in a body with a mind)? That is, we know the brain with its embodied modelling relation with the world is a really complex example of living mindfulness. It meets your working definition in terms of "the set of conditions experienced, and functions exercised, by a psychophysical being which produce personal and social behaviour."
But boil down an actual human that has grown up as a set of interpretive habits in the world into the simplest description of the trick involved, and you get the general thing that is the irreducible triadic relation described by Peircean semiosis.
And I also put all my money on this being a pan-semiotic deal as fundamental physics is arriving at the same irreducible triadic process as the causal explanation of how existence itself could come to be. A story of constraints and degrees of freedom emerging from the symmetry-breaking of fundamental indeterminism.
Or going right back to Anaximander, the dialectical process of apokrisis which organised the formless and boundless chaos of the Apeiron.