Выбрать главу

Functionalist Philosopher: What evidence could support your faith that consciousness could never be explained? We can see it simply as our name for what happens when certain processes run in our brains.

I would agree with that second opinion, except that we also need to say more about what those ‘certain processes’ do—and why we distinguish them as a group. (The next section will offer a theory of this.) Still, many thinkers still maintain that brains must be based on something beyond the reach of our present-day machines.

Emergentist: Perhaps consciousness is just one of those ‘wholes’ that emerge when systems get complex enough. Perhaps that’s just what we should expect from the network of billions of cells in a brain.

When we increase a system’s size, then it will usually work less well, unless we also improve its design, and that always involves some compromise; if a system is built with too many connections, this will lead to traffic jams—while if the connections between its parts are too sparse, it is unlikely to anything useful at all.

Besides, if mere complexity were all it needs, then almost everything would have consciousness. We don’t want to conclude that water-waves think—yet the manner in which a wave breaks on a beach is more complex (at least in some ways) than the processes that go on in our brains.

So, there’s no point to asking what consciousness ‘is’—because we’ve seen that this is a suitcase word, which we each fill up with far more stuff than could possibly have just one common cause. It makes no sense to try to discuss so many different things at once—except when trying to explain why we tend to treat all those things as the same. Let’s listen to Aaron Sloman again:

Aaron Sloman: “I for one, do not think defining consciousness is important at all, and I believe that it diverts attention from important and difficult problems. The whole idea is based on a fundamental misconception that just because there is a noun “consciousness” there is some ‘thing’ like magnetism or electricity or pressure or temperature, and that it’s worth looking for correlates of that thing. Or on the misconception that it is worth trying to prove that certain mechanisms can or cannot produce ‘it’, or trying to find out how ‘it’ evolved, or trying to find out which animals have ‘it’, or trying to decide at which moment ‘it’ starts when a fetus develops, or at which moment ‘it’ stops when brain death occurs, etc. There will not be one thing to be correlated but a very large collection of very different things.”[55]

I completely agree with Sloman’s view. To understand how our thinking works, we must study those “very different things” and then ask what kinds of machinery could accomplish some or all of them. In other words, we must try to design—as opposed to define—machines that can do what our minds can do.

∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞∞

§4-3. How do we recognize Consciousness?

Student: You still did not answer my question on why, if “consciousness” is just a suitcase word, what makes it seem like such a definite thing.

Here is a theory of why that could happen: Most of our mental activities run more or less ‘unconsciously’—in the sense that we’re barely aware of them. But when we encounter obstacles, this starts up some high-level processes that have some properties like these:

(1) They make use of our most recent memories.

(2) They operate more serially, than in parallel.

(3) They use abstract, symbolic, or verbal descriptions

(4) They use models that we have made of ourselves.

Now suppose that a brain could construct a resource called C that detects when all these are running at once:

If such a C-detector turned out to be useful enough, this could lead us to imagine that it detects the presence of some sort of ‘Consciousness-Thing!’ Indeed, we might even imagine that entity to be the cause of that set of activities, and our language systems might learn to connect this kind of detector to terms like ‘awareness,’ ‘myself,’ ‘attention,’ or ‘Me’. To see how this might be useful to us, let’s examine its four constituents.

Recent Memories: Why must consciousness involve memory? I’ve always thought of consciousness as about the present, not the past—about what’s happening right now.

For any mind (or any machine) to know what it has done, it needs some records of recent activities. For example, suppose that I asked, “Are you aware that you’re touching your ear?” Then you might reply, “Yes, I’m aware that I am doing that.” However, for you to make a statement like that, your language resources must be reacting to signals from other parts of your brain, which in turn have reacted to prior events. So, whatever you say (or think) about yourself, it takes time to collect that evidence.

More generally, this means that a brain cannot think about what it is thinking right now; the best it could do is to contemplate some records of some of its recent activities. There is no reason why some part of a brain could not think about what it has seen of the activities of other parts—but even then, there always will be at least so small delay in between.

Serial Processes. Why should our high-level processes tend to be more serial? Would it not be more efficient for us to do more things in parallel?

Most of the time in your everyday life, you do many things simultaneously; you have no trouble, all at once, to walk, talk, see, and scratch your ear. But few can do a passable job at drawing a circle and square at once by using both of their hands.

Citizen: Perhaps each of those two particular tasks demands so much of your attention that you can’t concentrate on the other one.

That would make sense if you assume that attention is some sort of thing that comes in limited quantities—but then we would need a theory about what might impose this kind of limitation, yet still can walk, talk and see all at once. One explanation of this could be that such limits appear when resources conflict. For, suppose that two tasks are so similar that they both need to use the same mental resources. Then if we try to do both jobs at once, one of them will be forced to stop—and the more such conflicts arise in our brains, the fewer such jobs we can do simultaneously.

Then why can we see, walk, and talk all at once? This presumably happens because our brains contain substantially separate systems for these—located in different parts of the brain—so that their resources don’t conflict so often. However, when we have to solve a problem that’s highly complex then we usually have only one recourse: somehow to break it up into several parts—each of which may require some high-level planning and thinking. For example each of those subgoals might require us to develop one or more little ‘theories’ about the situation—and then do some mental experiments to see if these are plausible.

вернуться

55

In sci.psychology.consciousness, 15 Jun 96.