Do Zombies Dream of Undead Sheep?

by rsbakker

My wife gave me my first Kindle this Christmas, so I purchased a couple of those ‘If only I had a Kindle’ titles I have encountered over the years. I began with Routledge’s reboot of Brie Gertler’s collection, Privileged Access. The first essay happens to be Dretske’s “How Do You Know You are Not a Zombie?” an article I had hoped to post on for a while now as a means to underscore the inscrutability of metacognitive awareness. To explain how you know you’re not a zombie, you need to explain how you know you possess conscious experience.

What Dretske is describing, in fact, is nothing other than medial neglect; our abject blindness to the structure and dynamics of our own cognitive capacities. What I hope to show is the way the theoretical resources of Heuristic Neglect Theory allow us to explain a good number of the perplexities uncovered by Dretske in this awesome little piece. If Gertler’s anthology demonstrates anything decisively, it’s the abject inability of our traditional tools to decisively answer any of the questions posed. As William Lycan admits at the conclusion of his contribution, “[t]he moral is that introspection will not be well understood anytime soon.”

Dretske himself thinks his own question is ridiculous. He doesn’t believe he’s a zombie—he knows, in other words, that he possesses awareness. The question is how does he or anyone else know this. What in conscious experience evidences the conclusion that we are conscious or aware of that experience? “There is nothing you are aware of, external or internal,” Dretske will conclude, “that tells you that, unlike a zombie, you are aware of it.”

The primary problem, he suggests, is the apparent ‘transparency’ of conscious experience, the fact that attending to experience amounts to attending to whatever is being experienced.

“Watching your son do somersaults in the living room is not like watching the Olympics on television. Perception of your son may involve mental representations, but, if it does, the perception is not secured, as it is with objects seen on television, by awareness of these intermediate representations. It is the occurrence of (appropriately situated) representations in us, not our awareness of them that makes us aware of the external object being represented.”

Experience in the former sense, watching somersaults, is characterized by a lack of awareness of any intermediaries. Experience is characterized, in other words, by metacognitive insensitivity to the enabling dimension of cognition. This, as it turns out, is the definition of medial neglect.

So then, given medial neglect, what faculty renders us aware of our awareness? The traditional answer, of course, is introspection. But then the question becomes one of what introspection consists in.

“In one sense, a perfectly trivial sense, introspection is the answer to our question. It has to be. We know by introspection that we are not zombies, that we are aware of things around (and in) us. I say this is trivial because ‘introspection’ is just a convenient word to describe our way of knowing what is going on in our own mind, and anyone convinced that we know – at least sometimes – what is going on in our own mind and, therefore, that we have a mind and, therefore, that we are not zombies, must believe that introspection is the answer we are looking for.”

Introspection, he’s saying, is just the posit used to paper over the fact of medial neglect, the name for a capacity that escapes awareness altogether. And this, he points out, dooms inner sense models either to perpetual underdetermination, or the charge of triviality.

“Unless an inner sense model of introspection specifies an object of awareness whose properties (like the properties of beer bottles) indicate the facts we come to know about, an inner sense model of introspection does not tell us how we know we have conscious experiences. It merely tells us that, somehow, we know it. This is not in dispute.”

The problem is pretty clear. We have conscious experiences, but we have no conscious experience of the mechanisms mediating conscious experience. But there’s a further problem as well. As Stanislau Dehaene puts it, “[w]e constantly overestimate our awareness—even when we are aware of glaring gaps in our awareness” (Consciousness and the Brain, 79). Our insensitivity to the structure and dynamics of cognition out-and-out entails  insensitivity to the limits of cognition as well.

“There is a perspective we have on the world, a ‘boundary’, if you will, between things we see and things we don’t see. And of the things we see, there are parts (surfaces) we see and parts (surfaces) we don’t see. This partition determines a point of view that changes as we move around.”

What Dretske calls ‘partition’ here, Continental phenomenologists call ‘horizon,’ an experiential boundary that does not appear within experience—what I like to call a ‘limit-with-one-side’ (LWOS). The most immediately available–and quite dramatic, I think–example is the boundary of your visual field, the way vision trails into oblivion instead of darkness. To see the boundary of seeing as such we would have to see what lays beyond sight. To the extent that darkness is something seen, it simply cannot demarcate the limit of your visual field.

“Points of view, perspectives, boundaries and horizons certainly exist in vision, but they are not things you see. You don’t see them for the same reason you don’t feel the boundaries between objects you touch and those you don’t. Tactile boundaries are not tactile and visual boundaries are not visible. There is a difference between the surfaces you see and the surfaces you don’t see, and this difference determines a ‘point of view’ on the world, but you don’t see your point of view.”

Our perspective, in other words, is hemmed at every turn by limits-with-one-side. Conscious experience possesses what might be called a multi-modal neglect structure: limits on availability and capacity that circumscribe what can be perceived or cognized.

When it comes to environmental cognition, the horizons are both circumstantially contingent, varying according to things like position and prior experience, and congenital, fixed according to our various sensory and cognitive capacities. We can chase a squirrel around a tree (to use James’ famous example from What Pragmatism Means), engage in what Karl Friston calls ‘active inference,’ but barring scientific instrumentation, we cannot chase a squirrel around the electromagnetic spectrum. We can see the backside of countless environmental features, but we have no way of contemporaneously seeing the biological backside of sight. (As Wittgenstein famously puts it in the Tractatus, “nothing in the visual field allows you to infer it is seen by an eye” (5.633)). For some reason, all or our cognitive and perceptual modalities suffer their own version of medial neglect.

For Dretske, the important point is the Heideggerean one (though I’m sure the closest he ever came to Heidegger was a night of drinking with Dreyfus!): that LWOS prevent any perspective on our perspective as such. For a perspective to contemporaneously appear in experience, it would cease to possess LWOS and so cease to be a perspective.

We perceive and cognize but a slice of ourselves and our environments, as must be the case on any plausible biological account of cognition. In a sense, what Dretske is calling attention to is so obvious as to escape interrogation altogether: Why medial neglect? We have a vast number of cognitive degrees of freedom relative to our environments, and yet we have so few relative to ourselves. Why? Biologically speaking, why should a human find itself so difficult to cognize?

Believe it or not, no one in Gertler’s collection tackles this question. In fact, since they begin presuming the veracity of various traditional ontologizations of experience and cognition, consciousness and intentionality, they actually have no way of posing this question. Rather than seeing the question of self-knowledge as the question of how a brain could possibly communicate/cognize its own activity, they see it as the question of how a mind can know its own mental states. They insist on beginning, as Dretske shows, where the evidence is not.

Biologically speaking, humanity was all but doomed to be confounded by itself. One big reason is simply indisposition: the machinery of seeing is indisposed, too busy seeing. This is what renders modality specific medial neglect, our inability ‘to see seeing’ and the like inescapable. Another involves the astronomical complexity of cognitive processes. Nothing prevents us from seeing where touch ends, or where hearing is mistaken. What one modality neglects can be cognized by another, then subsequently integrated. The problem is that the complexity of these cognitive processes far, far outruns their cognitive capacity. As the bumper-sticker declares, if our brains were so simple we could understand them, we would be too simple to understand our brains!

The facts underwriting medial neglect mean that, from an evolutionary perspective, we should expect cognitive sensitivity to enabling systems to be opportunistic (special purpose) as opposed to accurate (general purpose). Suddenly Dretske’s question of how we know we’re aware becomes the far less demanding question of how could a species such as ours report awareness? As Dretske says, we perceive/cognize but a slice of our environments, those strategic bits unearthed by evolution. Given that introspection is a biological capacity (and what else would it be?), we can surmise that it perceives/cognizes but a slice as well. And given the facts of indisposition and complexity, we can suppose that slice will be both fractionate and heuristic. In other words, we should expect introspection (to the extent it makes sense to speak of any such unified capacity) consists of metacognitive hacks geared to the solution of ancestral problems.

What Gertler and her academic confrere’s call ‘privileged access’ is actually a matter of specialized access and capacity, the ability to derive as many practical solutions as possible out of as little information as possible.

So what are we to make of the philosophical retasking of these metacognitive hacks? Given our blindness to the structure and dynamics of our metacognitive capacities, we had no way of intuiting how few degrees of metacognitive freedom we possessed–short, that is, of the consequences of our inquiries. How much more evidence of this lack of evidence do we need? Brie Gertler’s anthology, I think, wonderfully illustrates the way repurposing metacognitive hacks to answer philosophical questions inevitably crashes them. If we persist it’s because our fractionate slice is utterly insensitive to its own heuristic parochialism—because these capacities also suffer medial neglect! Availability initially geared to catching our tongue and the like becomes endless speculative fodder.

Consider an apparently obvious but endlessly controversial property of conscious experience, ‘transparency’ (or ‘intentional inexistence’) the way the only thing ‘in experience’ (its ‘content’) is precisely what lies outside experience. Why not suppose transparency—something which remains spectacularly inexplicable—is actually a medial artifact? The availability for conscious experience of only things admitting (originally ancestral) conscious solution is surely no accident. Conscious experience, as a biological artifact, is ‘need to know’ the same as everything else. Does the interval between sign and signified, subject and object, belief and proposition, experience and environment shout transparency, a miraculous vehicular vanishing act, or does it bellow medial neglect, our opportunistic obliviousness to the superordinate machinery enabling consciousness and cognition.

The latter strikes me as the far more plausible possibility, especially since its the very kind of problem one should expect, given the empirical inescapability of medial neglect.

Where transparency renders conscious experience naturalistically inscrutable, something hanging inexplicably in the neural millhouse, medial neglect renders it a component of a shallow information ecology, something broadcast to facilitate any number of possible behavioural advantages in practical contexts. Consciousness cuts the natural world at the joints—of this I have no doubt—but conscious experience, what we report day-in and day-out, cuts only certain classes of problems ‘at the joints.’ And what Dretske shows us, quite clearly, I think, is that the nature of conscious experience does not itself belong to that class of problems—at least not in any way that doesn’t leave us gasping for decisive evidence.

How do we know we’re not zombies? On Heuristic Neglect, the answer is straightforward (at certain level of biological generality at least): via one among multiple metacognitive hacks adapted to circumventing medial neglect, and even then, only so far as our ancestors required.

In other words, barely, if at all. The fact is, self-knowledge was never so important to reproduction as to warrant the requisite hardware.