As we encounter things in the world around us, when do we judge something to be just a heap or aggregate of smaller things, like a pile of sand, and when do we judge it to be a true, unified, single thing? It depends, almost always, on how you look at it. I have argued that when we look at the world in strict reductionist terms, nothing above the sub-atomic level really counts as a holistic thing. Are there any things above the micro level that really are inherent, single things in a way that does not depend on how you look at them? Do we have any reason to believe that there are, in contrast to the reductionist view, inherently unitary mid-level things in the universe?
I have an art nouveau poster in which a woman is smoking, and there is a stylized curl of smoke rising from her cigarette. When I look at that languid asymmetrical curve, I see the continuous curve in its entirety, all at once. I do not just have some kind of cognitive access to the fact of the curve. The parameters of the curve are not just available to me upon making certain kinds of inquiries. I do not just have a pointer or reference to a lot of data beyond my view that yields results pertaining to the curve when evaluated. The details of my perception are not just at my fingertips, but bang! right there, live, all at once. I see the whole curve now. Of an intelligent computer with its video monitor aimed at the curve (LDA, STA, JMP…), all we can say is that at some level it may be thought of (by us) as seeing the curve. That is, given an abstract understanding of its algorithm and data structures, one may interpret the functioning of the machine as "seeing" the curve. When analyzed in certain terms or thought of in a certain way, it is "seeing" the curve. This, however, is anthropomorphizing on our part, albeit on the basis of the computer's deliberately programmed design.
There is, in contrast, nothing "may be thought of" about my seeing the curve. My seeing the curve is not a matter of interpretation. It is an absolute fact of Nature that I really do see that curve all at once, before me. Seen at the low level, as the ant-like CPU crawling over the data-gravel, there is no inherent sense in which "it all comes together" for the computer, whereas there is an inherent sense in which it all comes together for me.
This is not just another "I see red, the computer will never see red" argument (although it is perhaps related). The "seeing red" arguments focus on qualitatively rich but nevertheless cognitively simple aspects of experience. I am talking instead about our ability to have cognitively complicated scenes before us in our mind's eye, to see the complex as one thing, all at once in its entirety: e pluribus unum. This is sometimes referred to as the unity of consciousness.
I would like to distinguish this from the so-called binding problem, however. The binding problem refers to the fact that, for example, the visual processing parts of the brain and the auditory processing parts are quite different, and in fact take different amounts of time to do their jobs. In spite of these facts, we can have a single experience that incorporates elements from several senses at the same time, and they are synchronized. The binding problem is fascinating in its own right, but what I am talking about here is, I think, at least as fundamental. I am concerned not so much with the way in which different sense modalities (vision, hearing, smell, etc.) can be bound together in a single percept, but how anything at all, even within a single sense modality, may have any kind of unity at all.
The upshot of all of this is that we do not live in a reductionist universe. That is to say, there are inherent, absolute things above the level of the quark, but below the level of the whole universe itself. These mid-level things may only exist in our minds, but that is enough to say that they do exist. My moment of consciousness as I look at a tree is absolutely, indubitably, a single thing. There are inherent things in my conscious mind that spread across or incorporate any lower level things that might be taken as their elements. Like my seeing red, these things in my mind can not be illusory. If it seems that there are mid-level unitary things among my percepts, then those seemings themselves must be mid-level unitary things. They really exist in the universe.
It could be argued that my percept of a tree is not an indivisible whole: you can easily break it into parts. But that only means that I have a tree percept, then, often by effort of willful analysis, I have a subsequent follow-on percept of tree parts, albeit possibly with tendrils of reference reaching back to the original unitary tree percept. Just because a cathedral is made of stones, it does not follow that my conception of a cathedral is made of my conception of stones. Even if my conception of the cathedral incorporates the knowledge of the stones, there is still a single experienced percept of the cathedral that subsumes this fact.
My percepts are immediately, manifestly unitary whole things. Regardless of the cognitive or physiological mechanism which supports them, they provide me with a counter-example to the doctrine of ontological reductionism. I know I perceive my percepts, and that those percepts really are whole objects just as certainly as I know I see red. Things, in my mind, are qualia, as are all abstractions - manifestly before me, all at once. A thing is an abstraction, and all abstractions are things. In contrast, a car just is a heap of its atomic parts, doing what they must whether you think of them collectively as a car or not.
I think that this unique status of our objects of consciousness as mid-level inherent things is at least as important as the fact that red seems red to me. Consciousness gives us not only examples that there are such things as qualitative essences in the universe, but also that there are such things as things. This argument may strike some people as a case of comparing apples and oranges. "Just because you perceive something as an inherent whole doesn't mean it actually is an inherent whole", one might be tempted to argue. "You are just interpreting it that way." But it is the percept itself, the interpretation, not the thing out there in the world that is being perceived, that I am talking about.
I realize that this line of thought represents a whole new level of taking first person phenomenal experience seriously. Nevertheless, if we are going to be honest and fearless as we try to figure out the sorts of things and forces that are at work in the universe, we must take this step. We must take first person experience seriously, both in the seeing red case and in the case of the unity of our percepts. Both (and perhaps more besides) must be explainable in any final theory of nature we concoct. Such a theory must include principles of individuation that allow for the mid-level things that are my percepts. Gregg Rosenberg discusses this quite a bit (although from a somewhat different perspective). To use his term, we need a theory of natural individuals.
My conscious perceptions are mid-level things, and they have qualitative essences which outrun their functional descriptions. I want to emphasize that when I say "mid-level", I am talking about the scale (between quark and universe), and definitely not implying that these things occupy some middle level of a tree of organization. In that sense, the whole point is that these are low-level things. They are big and complex, yet they must count as primitive objects in the sense that there is no lower level of description or analysis in terms of which they may be exhaustively characterized. There is certainly a huge number of possible conscious percepts - quite possibly infinite. All this being true, we live in a universe in which there is a huge (possibly infinite) number of fundamental components, these components have qualitative essences, and they are big and rich, not tiny and simple. Any formulation of reductionism that could accommodate these facts would hardly be worthy of the name.
It is worth noting, however, that this view is nevertheless reductionist in a sense. Everything in the universe may well be reducible in principle to its component parts - it is just that there is no small number of such fundamental components in the universe, and a lot of those fundamental components are pretty substantial things in their own right. The important respect in which it still counts as a form of reductionism is that under this view, you do not get anything out that isn't there in the lowest levels. Specifically, this view does not posit any magic "emerging" from a system on the basis of its "complexity" or functional organization.