Media, Science:
Dennett's Consciousness Explained

by Daniel C. Dennett (1991)

Dennett is a philosopher who takes hard science very seriously, especially cognitive psychology. This book changed my concept of the human being. Dennett reveals the flaws of the "normal" view of human consciouness (that there's a little person in your head watching your body's input on a big screen) and reveals how persistent this metaphor is even among those who ought to know better. If you think you don't believe in the little person sitting in front of the screen, you might want to read this book to be sure that this metaphor doesn't still affect your model of consciousness. It affected mine. Dennett provides a new hypothesis of human consciousness, basically that consciousness is a set of actions in the brain, which actions are not strictly related in serial time. What I took away from Consciousness Explained is:

Rapid Access
You're aware of a lot less at any one time than you think you are. The body is set up to gather data quickly when you need it, so quickly that you usually think you already knew it. Instead of the brain having an "internal movie screen" with your visual field displayed on it, it's simply capable of finding out anything in your visual field at a moment's notice, faster than thought.

Unconscious Subsystems
A conscious system ought to be made up of simpler subsystems that themselves are unconscious (in the same way that a living being is made up of subsystems that, in themselves, are not alive). The concept of a consciousness separate from and in addition to these unconscious subsystems is extraneous, like the concept of a life spark separate from and in addition to the not-really-alive subsystems in a body.

Gappy Consciousness
The "stream of consciousness" that looks to me like a smooth-running, 3-D, feel-o-rama movie is more like a non-linear series of impressions, with the blank spots unnoticed because they're blank.

The first time I read
Consciousness Explained, I couldn't follow the material on the timing of mental representations of time. The second reading, I think I got it, and it's yet another shock to the commonplace theory of self.

Even if your brain registers content A after content B, if it concludes that A happened before content B, then we perceive it as happening first. This is a big idea. You don't first experience content B, then experience content A, and then judge that A happened first. Instead, content B takes place, then content A takes place, and content A seems like it happened first. This out-of-sequence timing occurs for very fleeting events. The brain's fast enough to get slower events in chronological order.

It should be obvious that the order in which your brain registers content and the order in which that content seems to happen in the outside world need not coincide. The color of the apples seems to be red even though there's no red in your brain corresponding to the apple's color. Likewise, content A seems to be first even though it took shape in the brain after content B.

You don't experience moments one after the other like someone sitting in a movie theater watching one's life on the screen. Your sense of time is a sense like your others.

Outstanding Issue: Qualia
What I'd really like is for someone to read this book and tell me what "red" is. Dennett demonstrates to his satisfaction that there's no real sense to the question "Why is red red and not green?" but I can't follow him there. While he trashes the idea that the difference between "red" and "green" is practically impossible to pin down, what about the difference between "red" and "sweet"? Likewise, he points out that one person's experience of the taste of beer is different from another's, and one person's experience of the taste even changes over time. But we experience color as color and not as smell. It might be nonsene to ask whether two people are experiencing the same flavor, but it's not nonsense to ask whether two people are both experiencing color or taste, is it?

My guess is that Dennett's describing consciousness is like Darwin's describing evolution when people talked about "blood" instead of genes: the theory right in general, but there's a missing concept without which the theory isn't fully explicable. Dennett's hypothesis seems right, but I can't help but feeling that there's a leap he's making that won't be a leap any more, once some new scientific discoveries show us the bridge across the conceptual chasm.

Outstanding Issue: Immortality
One thing I don't get about
Consciousness Explained is Dennett's conclusion that his theory of the self allows for meaningful immortality. He describes the self as an abstraction, a "Center of Narrative Gravity." He says that its content is ideas, and so it can be represented in different media and still be basically the same thing, as the story of Romeo and Juliet can be basically the same whether it's a play or a movie. Thus one could, theoretically, replicate one's self on a computer (a superadvanced, futuristic computer, anyway).

I don't see that as meaningful immortality. It wouldn't do me any good to have a computer replica of me enjoying life on the other side of the world. Nor would it do me any good to have a computer replica of me enjoying life in the future. Sure, in either case the computer replica would be "me" as near as anyone could tell, but it wouldn't be me being me. (It's Jehovah's clones all over again.)

What's the difference between me and a robot just like me? you might ask.

None. Physical immortality wouldn't do me any good, either.

Tangent: The Matrix
Dennett's opening thought experiments implicitly trash the idea that columns of green text running up a screen could be the code for a virtual reality, "the matrix." Basically, there's way too much information coming in through the senses to be encoded through such a narrow channel.

June 2001, April 2003

Peter Donis



Rorty & Dennett on Truth and Perception: another angle on Dennett

center of gravity: Center of mass, balance point; an idea, something that's at once useful and fictitious.

center of narrative gravity: The self whose theory Dennett describes. This concept embodies the terms "center of gravity" and "narrative."

narrative: If the subjectivity of postmodern thought drives you nuts, then look out for the word "narrative." "Narrative" basically means "account." It's a story, myth, theory, novel, tenet, or other recounting of events. What makes this term popular among the postmodernists is that it doesn't prejudge the nature or accuracy of the "narrative." The periodic table of the elements is a narrative. So is the Bible. Only someone dedicated to withholding judgment would put the Bible and the periodic table of elements in the same category.