Much of the confusion surrounding philosophy of consciousness is due to exactly the fact that it is not yet a science of consciousness: messy definitions, many interwoven but different perspectives, and even completely distinct subjects of inquiry.
We need to be able to ask better questions in order to arrive closer to the reality of the matter. And for that, we need an accurately constructed ontology for the subject.
And in order to pave the ground for that, I'm going to provide a thought experiment that I call The Copy Test, which is meant to intuitively guide to a number of basic, and hopefully accurate elements of a more coherent and correct ontological model of 'consciousness'.
But first, a basic framing:
The Felt Barrier
By 'consciousness', I am referring to the 'experience of experience', i.e. the most fundamental sense we posses, of which all concrete experiences are mere 'flavors'. The experience of experience is equivalent to a sense of separation from the environment. For a sensation to be felt--say taste--there has to be something which tastes, and something which is being tasted, i.e. a felt barrier is formed.
The experience of experience grounds us, 'localizes us', is the basis of what we refer to as our consciousness, and even rocks could be imagined possessing it. Consequently, this is not a question of rationality or intelligence, but felt senses, both external and internal. Experience of experience, or the felt barrier, is not to be confused with self-awareness either, which is a result of a linguistic expression, a rational process. Separation, or the experience of experience, is felt, and is feeling.
The Copy Test
There are two rooms, in one of them--a person, and the other one is empty. Except for the person, the rooms themselves are identical over time. An advanced copy agent then creates an exact copy of the person, in the other room. From that single moment in time, two physical persons--distinct in space but exactly equivalent physically--exist. What happens relating to the consciousness(es) over time?
Imagine if this happened to you--right now as you are reading this sentence. Take a second, a minute, to imagine an atom-perfect copy of yourself appearing next to you. Would there be two "yous"? Which one would you experience, truly feel? What happens to the barrier?
Consciousness as a Matter of Physicality
If consciousness is a matter of processing information, are the consciousnesses of the person and the copy identical consciousnesses? If both the person and the copy sense the same stimulus, and process it in the same way, how can there exist two distinct barriers?
From these two intuition pumps we could arrive at the following: consciousness is not a matter of processing information, but rather an inherent property of physical matter, which our brains merely 'shape' into senses.
Science likely disagrees with the above explanation of the origin of experience. There is hardly any subatomic particle that contains within itself the capacity for subjective experience--'feelions' don't exist.
Let us invoke another thought experiment which revolves around the concept of a P-zombie, a non-feeling entity: it is easy to imagine a person who behaves, to the eyes of an observer, as a normal human being, yet completely lacks subjective experience, it has no experience of experience. From our current, scientific point of view, consciousness isn't a requirement for pretty much anything--we could all be unaware robots and the world would look just the same.
We have therefore arrived at a conundrum: experience isn't tied to physical matter directly, it is not a requirement for learned behavior, and due to the Copy Test, cannot be a mere matter of information-processing. What else is left to explain experience?
At the moment, I have no idea.