Metzinger, Being No One, page 173:
Phenomenal representations are transparent, because their content seems to be fixed in all possible contexts: The book you now hold in your hands will always stay this very same book according to your subjective experience, no matter how much the external perceptual situation changes. What you are now experiencing is not an “active object emulator,” which has just been embedded in your global model of reality, but simply the content of the underlying representational dynamics: this book, as here (constraint 3) and now (constraint 2) effortlessly given to you (constraint 7). At this level it may, perhaps, be helpful to clarify the concept of transparency with regard to the current theoretical context by returning to more traditional conceptual tools, by once again differentiating between the vehicle and the content of a representation, between the representational carrier and its representational content.
The representational carrier of your phenomenal experience is a certain process in the brain. This process, which in no concrete way possesses anything “booklike,” is not consciously experienced by yourself; it is transparent in the sense of you looking through it. What you are looking onto is its representational content, the existence of a book, here and now, as given through your sensory organs. This content, therefore, is an abstract property of the concrete representational state in your brain. However, as we have already seen, there are at least two kinds of content. The intentional content of the relevant states in your head depends on the fact of this book actually existing, and of the relevant state being a reliable instrument for gaining knowledge in general. If this representational carrier is a good and reliably functioning instrument for generating knowledge about the external world, then, by its very transparency, it permits you to directly, as it were, look “through it” right onto the book. It makes the information carried by it globally available (constraint 1), without your having to care about how this little miracle is achieved. The phenomenal content of your currently active book representation is what stays the same, no matter if the book exists or not. It is solely determined by internal properties of the nervous system.
Now, I agree with Metzinger to a certain extent. When our experience (falsely) seems to be transparent, this is because we are looking through the brain process (just as we might look through a window), without being aware that the window is there, i.e. without being aware that this process is going on (that the window is an intervening medium), So-called “naive realism” is false (as Metzinger rightly insists), because our sense of transparency causes us to ignore the mental medium through which the thing is transmitted to us; and as we know, every medium involves a “translation” rather than an unchanged conveyance.
What I reject from Metzinger, however, is the idea that what we see through the “window” of mental process is itself another mental product. (In Metzinger’s terms: what we see through the representational vehicle is the representational contents). No, I want to claim rather that this doubling is unnecessary. What we see through the brain process (or through the window) is not a “representational content”, but is actually the thing itself on the other side of the window (in Metzinger’s example, the book). The “content” that we see through the vehicle of brain processes (of which we are unaware) is not a representation, but the actual thing that we are looking at. Metzinger’s representationalism causes him to double the process of transmission.
Metzinger posits this doubling because, he argues, we could be hallucinating, i.e. there might not really be a book there at all. But I don’t think this is a sufficient reason to argue that what we are seeing is a mental simulation or representational contents, rather than an actual thing. Just a few pages earlier, Metzinger speaks of hallucinations generated by drugs like LSD: in such cases, he says, phenomenal transparency is interrupted because “what the subject becomes aware of are earlier processing stages in his visual system: the moving patterns [seen by someone hallucinating as a result of LSD] simply are these stages.” So when we are hallucinating, we are still perceiving something actual; it is just that what we are perceiving is our own (usually inaccessible) brain process, as opposed to things that we see with that brain process. This would also be the case if we hallucinate an object that isn’t there, and that our brain might generate via memory traces (there is no book there now, but I have seen books before, so the appearance of the book is part of my perception of my own process of perception).
In short, Metzinger argues from the possibility of hallucination that “your phenomenal life does not unfold in a world, but only in a world-model”; and that when we realize that what we are perceiving is in fact a hallucination, this means that the process of our mental activity (the process of “modeling”, or representing or simulating) itself “becomes globally available.” But I want to argue that this brain process itself is part of the world, and unfolds in the world; and that when we become aware of this, we are perceiving an additional part of what is going on in the world, rather than a second-order representation at a distance from the world.
This also leads back to what Whitehead calls “nonsensuous perception.” Metzinger distinguishes between intentional and phenomenal contents of perceptual experience. What Metzinger calls “intentional” is what happens when the perception is cognized. But, as Whitehead suggests, cognition is only a very belated and complex result of integrating many prehensions: i.e. it is only a derivative (which only happens in certain especially complex cases) of the far more basic pre-cognitive “prehension” of the thing. And this nonsensuous and precognitive sort of perception corresponds, more or less, to what Metzinger calls the “phenomenal” level of experience. Metzinger’s phenomenality (the most basic sort of “consciousness”) is the noncognitive (or precognitive) and affective basis of perception. This is what I think of as the nonphenomenological and nonintentional — or “autistic” — level of primordial experience. Because it preceides cognition, it is singular and not susceptible to representation: it is, in a Kantian sense, “aesthetic” rather than a matter of “understanding.” Metzinger mentions many sorts of noncognitive perceptions or experiences in his book; think, for instance, of “Raffman qualia,” or shades of color that can be phenomenally experienced by not identified, recognized, recalled, or remembered. Such basic or noncognitive perceptions are in a certain sense, as Metzinger suggests, “internal,” and capable of taking place as hallucination, even in the absence of an actual outside object. But even in the case of hallucination, “experience” on this level is, I insist, a process of prehension, and not a “representation.”
A few pages later Metzinger adds that “it is interesting to note how cognitive availability alone is not sufficient to break through the realism characterizing phenomenal experience. You cannot simply “think yourself out” of the phenomenal model of reality by changing your beliefs about this model. The transparency of phenomenal representations is cognitively impenetrable; phenomenal knowledge is not identical to conceptual or propositional knowledge.”
Now, I think that this is entirely right. My only disagreement is that think Metzinger gives too small a role to nonconceptual experience. Such experience precisely isn’t “knowledge”; but in order to deal with it, we need to break free from the prejudice that only the cognitively functional aspects of mentality matter.