I've written a lot on the subject of consciousness over years. In that time I've expressed my philosophical slant towards idealism, a philosophy that I see as the only chance of making sense of consciousness. In trying to summarize my view I would give account of my own version of idealism as follows:
The Problem
There seems to be an incommensurability, or conceptual disconnect between conscious cognition and the material world of particles which make up the many kinds of dynamic configurations we perceive around us. What is it about a dynamic configuration such as we see in the neural structure of the brain which makes it conscious? The problem is compounded by recent strides in Artificial Intelligence which are starting to do a good job of simulating at least some aspects of human behavior. The AI problem seems to be simply a case of creating the right kind of dynamic configurations which imitate human thinking. In trying get the AI cognitive dynamic right the question of adding the sentient magic of consciousness doesn't come into it and in fact is of no help at all when trying to design AI systems. It is no surprise, therefore, that some people, misled by the third-person linguistic currency of science which deals largely with dynamic configurationalism and which is (necessarily) oblivious to the first-person perspective, will tell us that consciousness is a mirage or some kind of illusion; a position which is a bit like saying that pain and suffering are illusions and therefore what's the fuss all about?
But yes, on the face of it there is an issue here: In all our attempts to investigate the dynamic configurational basis of intelligence/sentience, whether by deeply probing neural structure or trying to simulate intelligence/sentience computationally the concept of consciousness simply doesn't come into our thinking: So, does it really exist?
The Solution.
The consciousness problem arises because of the seeming logical impossibility of finding consciousness even in the most sophisticated material configurations; for the closer you look at any configuration the more you find just further configurational detail and that is not what we mean by consciousness. I would explain that this is because conscious cognition is an entirely different genus of category to configurational categories; conscious cognition is the thing that is doing the looking, whereas material configurations are the things being looked at. The question "Where can one find consciousness in the physical regime?" is therefore unanswerable until our attention becomes focused back toward the observer rather than the observed.
So, if we are going to treat material configurationalism as fundamental, axiomatic and elemental we will never be able to solve the question of consciousness. The solution, then, is to turn the question around: Viz: If the perceptions of conscious cognition are taken as fundamental, and axiomatic can we then find a material physical a regime? The answer is a clear yes....
If the perceptions and qualia of sentience are sufficiently organized with mathematical precision and faultless registration it then becomes possible for conscious cognition to define material objects in terms of the mathematical logic controlling experience. But to do so would also require that conscious cognition is itself sufficiently organized, rational and sophisticated for it to be able to mentally construct material objects from its experience. The elegant twist in the logic here is that we find conscious cognition is itself describable in terms of the very material physical regime conscious cognition constructs and perceives. I love this twist of circular self-affirmation: As I've said before it so reminds me of the way a computer language compiler can be written in the very language it compiles; that is, a computer language is actually described in terms of itself. Likewise conscious cognition constructs and conceives the objects of the physical regime and discovers itself to be describable in the self-same terms of that physical regime*. See the introduction to my book where I grappled with these ideas.
The Thing-in-Itself
Of course, we can never know the nature of the thing-in-itself which delivers the organised patterning of our experiences (However, see Acts 17:28 for a possible Biblical answer). But if we have sufficient intelligence we can perceive and understand the organization of the experiential interface that this thing-in-itself mysteriously presents to us. It is this organization which enables us to define a rational physical regime of apparently "gritty" matter (or should that be "wirery" strings?). And at the same time we find that we can also self-describe ourselves in terms of that matter.
At this point one might be tempted to say that because the material physical regime is a mathematical construction made possible by the high organization & high registration of our experiential interface then it follows that "gritty matter" is a kind of mathematical illusion and that conscious cognition is the actual elemental & fundamental reality. This turn of phrase, which I have some (but not full) sympathy with, turns the "consciousness-is-an-illusion" philosophy on its head; if I say "gritty-matter-out-there is an illusion" it serves as a useful hyperbole to get the message of idealism across that the thinking conscious intelligence is fundamental and axiomatic to the cosmos.
But that message needs qualification: As I've said before, I suspect there are no bit parts in the material "illusion": I'd guess that no object is simply an experiential facade, unlike the characters and objects which appear in a novel or a computer game which are developed just enough to keep up the illusion of a deeper reality. All the mathematics of all the objects and characters in the story of matter have, I suggest, been worked out in full whether it be those distant galaxies or those events of the distant past.
So, am I claiming that life, the universe and everything is some kind of thorough computer simulation giving us a facade of apparently gritty matter? The answer to that is both "yes" and "no".
"Yes" because there is, I believe, some kind of matrix dedicated to supplying us with an experiential interface capable of empirically answering all the questions we put to it. This constitutes the equivalent of a kind of Turing test for an ontologically real world; as far as empirically interrogating this world is concerned the "illusion" seldom reveals itself to be an "illusion" and survives robust probing. But we just don't know the absolute nature of the medium on which this mathematics has been reified (although as a Christain I would quote Acts 17:28). Moreover, because the philosophy of idealism gives conscious cognition such a primary and fundamental place it helps to break us into the notion that divine conscious cognition is the a-priori matrix on which the physical regime is reified.
"No" because the computer simulation argument has only been presented in a way where it is clear that "gritty matter" is assumed to be axiomatic, elemental and fundamental. See here for my reaction to the computer simulation notion.
Very early on in my thinking career I was impressed by the logic of positivism; it seemed irrefutable that not only did all knowledge come via experience/observation but also the objects of the material world were meaningless without their ordered experiential base and the cognitive ability to construct them mathematically. This kind of logical positivism rightly assumed that the combination of organised experience and sophisticated cognitive abilities were axiomatic and fundamental. But where positivism was in danger of falling-over was that it was liable to render meaningless any thought that the constructions built from the data dots of experience pointed to a reality beyond the observer; history, distant galaxies and above all other sentient beings were in danger of, very counter intuitively, dissolving into nothingness, leaving us with a very egocentric solipsism. There had to be a matrix out there that was far more fundamental and elemental than the cognizant observer and which maintained that highly organised facade and interface to a real world. Given the primacy of sentience in the idealist philosophy, for me Acts 17:28 was a rational guess for the nature of the matrix, a guess that integrated and made sense of so much about the human predicament.
End Note:
My own highly speculative attempt at the physics of consciousness can be found here. I don't push this theory with any strong conviction, but just to prove that theorizing on consciousness should not be a taboo subject. What this theory lacks however is the colourful qualitative nature of conscious experience. Experiential qualities are irreducible to the formal black & white terms of configurationalism. Although Penrose's idea that conscious cognition is a correlate of incomputability is a possible line of inquiry I'm not impressed by this theory myself.
Footnote
* It must be understood that this self-description is only in terms of the formal structure of cognition as opposed to the qualities of conscious cognition: An AI system may be able to do a could job of formally simulating/describing the neural activity of the mind, but identity of formal structure is not a sufficient condition to create the qualia of consciousness.