 |
| Robert Wright's Nonzero: The Logic of Human Destiny |
But Darwinian natural selection cannot explain why advanced brains should be conscious.
Consciousness, as I interpret Wright's view of it, is the inner experience we have: what it is like to use our brains. Our brains go through various machinations at a neural or physical level, thereby accomplishing what neuroscientists and behavioral scientists call cognition. Cognition depends on perception, which, when we are dealing with stimuli we receive from the world at large, or from within our body, depends on sensation. Cognition organizes our actions in the world as we respond to our perceived situations.
But, says Wright, big-brained creatures of our general ilk don't actually need to be conscious of all this cognitive activity going on. There could, in some other, hypothetical world, be highly evolved zombies who have no inner experience of their cognitive brain states. These "robots with unusually good skin" would be just as capable as we are at doing all the things which natural selection intrinsically favors — they would be just as "fit" as we, in a Darwinian sense — but they would not be sentient.
That suggests to Wright that our consciousness is epiphenomenal, by which he means it is explanatorially irrelevant to any truly scientific view of human behavior and of how that behavior has evolved. Nothing which natural selection cannot "see," he says, belongs in any such view. Since consciousness doesn't actually "do" anything — since all of our behavior can be fully explained at a neural and physical level — natural selection is blind to it and cannot account for its presence.
Wright builds this view of consciousness into an argument that (a) modern communications may be linking us all together into one giant global brain, itself conscious, and (b) this may be the "purpose" behind evolution, such that it becomes a "non-crazy question" to ask if there is a God.
 |
| David J. Chalmers's The Conscious Mind |
I have already dipped into various portions of the book enough to learn that Chalmers "takes consciousness seriously." By this he means that he doesn't agree with the apparently something-like-one-in-three of scientists who claim a completely reductive and materialist theory of cognition would answer all the "easy" and "hard" questions about consciousness too.
Those other scientists, Chalmers says, are on the far side of a Great Divide. They are confident that consciousness is not only a completely natural phenomenon — Chalmers agrees with them on that much — but that it can be explanatorially reduced by everyday scientific methodology to physical-level activity, the workings of interconnected neurons. Chalmers, however, is a mind-body dualist, not a materialist. He thinks conscious mental states cannot be reduced to mere physical activity in the brain.
Chalmers furthermore thinks we need a science of consciousness, whose natural laws needn't be physical laws. Such a science would need a philosophical theory of consciousness to get it started. It would not be as dependent on observation as ordinary sciences are, since the only consciousness one can observe is one's own.
As a dualist, Chalmers holds that consciousness supervenes on physical brain states. It accordingly accompanies the cognitive brain states that give rise to it. This supervenience is natural, not logical: there might be, or this might have been, a "zombie world" where brains aren't conscious. But in our world, laws of nature dictate that consciousness tightly "coheres" with cognition — or, more canonically, with brain-like information processing in general.
What consciousness is composed of is phenomena. Consciousness — itself a phenomenon — attends to things in the physical world not as physical things per se but in terms of their phenomenality: physical things are thus also entities that, once they are perceived by the brain based on sensory input, produce qualia.
A red tricycle not only has the physical characteristics that make it red — say, paint that absorbs all but red light — it accordingly has the ability to produce in our consciousness "a qualitative feel — an associated quality of experience" (p. 4). A quale (KWAH-lay), the singular of qualia, is nothing more than a qualitative feel which is associated with the subjective experience of being aware of something.
The "something" of which we are consciously aware can be an object in the external world, such as a red tricycle, conveyed to our brain by sensory stimuli. It can also be something in our inner world — for example, a memory of a red tricycle, or a thought about tricycles in general, or a feeling of hunger, or a thought about consciousness. The object of which we are conscious can even be our "self"; the symbol which our brain maintains to represent its own identity also has a set of associated qualitative feels or qualia. In fact, anything of which we are consciously aware has associated qualia.
"These qualitative feels," Chalmers himself puts it, "are also known as phenomenal qualities, or qualia for short. The problem of explaining these phenomenal qualities is just the problem of explaining consciousness. This is the really hard part of the mind-body problem."
For example, a red tricycle's qualitative feel or qualia would include that phenomenal quality by which we judge it to be red. But how should we explain such phenomenal judgments of, say, redness in terms of our consciousness? This is one of the topics which Chalmers takes up in detail in the course of his book.
To me, Chalmers's view of consciousness and the judgments it enables u to make about phenomena themselves have something of the right "qualitative feel." I freely admit that I am biased in a way Chalmers is not. He says he took a lot of convincing before abandoning his original inclination toward strictly materialist and reductive explanations of all things.
His dualist theory of consciousness conceals no religious agenda, he says; he reports having "no strong spiritual or religious inclinations" (p. xiv). I will have to read the rest of the book to see whether he even mentions anything like Robert Wright's "non-crazy question" about consciousness implying purpose in the universe, and perhaps a God behind it.
My own bias is in favor of taking a view of consciousness which brings it into relation with the soul, that word being used in its religious or theological sense. So there will very likely be a point at which Chalmers and I part company; however, we agree that the conscious mind is not explainable in terms of physical, material causes.
Even Wright talks as if he is a hard-headed skeptic in no hurry to be convinced of any consciousness-God connection. To him, it's just a "non-crazy question." To me, it's more. I believe in God, in a way that goes along with my being a Christian of fairly liberal (for a Roman Catholic) theological persuasion.
I have an intuition that a phenomenological view of consciousness, such as that of Chalmers, offers a unique pathway into a religious worldview like mine. Like Wright and Chalmers, I believe consciousness is (at least to a first approximation) epiphenomenal; it is out of the "loop" of physical causation. So what is it here for? Why is it that the only thing we as persons really know directly is our conscious experience? Why is everything else filtered through that?
It is as if our world didn't have to be made that way — and if it is, it's because God decreed it.
God, who is himself personal, made a world that would in the normal course of evolution produce persons. God, who himself has a mind, made an evolving world that made us, with our own independent minds. God, himself conscious, sought fellowship with creatures who have their own inner experience.
That is the thrust of my own "qualitative feel" for the phenomenon of consciousness. I will explore it more as I continue to read Chalmers's book and comment on it in future posts in this series.
[This post was edited and revised on 5/10/07.]
