Bill Vallicella, over at Maverick Philosopher in very interesting post about the subsistence of souls, mentions the unity of consciousness, and says:
Sitting before a fire, I see the flames, feel the heat, smell the smoke, and hear the crackling of the logs. The sensory data are unified in one consciousness of a selfsame object. This unification does not take place in the eyes or in the ears or in the nostrils or in any other sense organ, and to say that it takes place in the brain is not a good answer. For the brain is a partite physical thing extended in space. If the unity of consciousness is identified with a portion of the brain, then the unity is destroyed. For no matter how small the portion of the brain, it has proper parts external to each other. Every portion of the brain, no matter how small, is a complex entity. But consciousness in the synthesis of a manifold is a simple unity. Hence the unity of consciousness cannot be understood along materialist lines.
I quote this, because it is one of the main reasons why I find holistic model plausible.
As Vallicella says, in the case of consciousness it is impossible to imagine how separate elements (of any kind, be it atoms, or some sense-data/qualia or whatever) can create a unity of experience as we have.
If you think it is possible, you are probably making a subtle fallacy. Namely we can imagine a configuration of parts as a whole, but when one is talking about parts constituting the whole, it is important to keep the parts in their assumed self-subsistence and determination as such, and be careful not to introduce into the imagination element which is not in them. And when we imagine the parts as constituting the whole, the quality of wholeness doesn’t in some way emerge from those parts, but it appears there only because it is our unity of consciousness in which we do the imagining. But, because this unity is that which is of need of explanation, it means that if we are critical in our thinking, we should stay with those abstractions (parts) in which we want to find the possibility to create whole. But that is impossible, as it is implicit in their being abstractions, that by their nature that they are just multitude which can’t by its own make quality of wholeness. The moment we imagine them together, we are adding quality of wholeness from our unity of consciousness.
Because of that, the whole must be taken as a fundamental principle, which can’t be reduced to some other abstractions. As it is clear from my past posts, I take being-in-the-world as this starting whole which is irreducible neither to subject and world, and of course not reducible to objectively existing things in the world, like atoms, energy or whatever.