Minds, Brains and Science [Paperback]

However, I remain struck by his argument against the possibility of what he terms the claims of "strong artificial intelligence" proponents. He describes this view (page 28) as "saying that the mind is to the brain as the program is to the computer hardware" and elaborates by noting that "on this view, any physical system . . . that had the right program with the right inputs and outputs would have a mind in exactly the same sense that you and I have minds." Thus, "strong AI," as he repeatedly terms it, is the view that minds are in no way unique to creatures like us (with organic brains like ours) but are merely the function of the right sort of programs on the right kind of hardware operating in the right sort of way. That is, inorganic machines, like digital computers, can be made to have minds like ours (with the same kinds of features ours have).

Searle is very much opposed to this view and in this book brings to bear his most famous argument against it: the Chinese Room thought experiment. In a nutshell it holds that a computer, insofar as it is no different from someone inside a sealed room following purely formal rules in responding to written questions submitted in Chinese (a language he doesn't know) can appear to be responding AS THOUGH HE KNEW CHINESE, so too, can that computer appear to have intelligence, to understand its inputs, without really doing so. His core argument against "strong AI" is that this is ALL a computer can do, but that simulation in this way is not what we mean by intelligence at all. In fact, he rightly notes, when we think of intelligence, we think of understanding, what he variously calls intentionality and/or meaning (semantic content). But the computer modelled on his Chinese Room evidences no understanding but only a rote process of mechanically producing certain squiggles, according to some pre-established rules that look like they reflect an understanding.

The crux of this is a syllogistic argument he also reproduces in this book:

1) Brains cause minds.
2) Syntax is not sufficient for semantics.
3) Computer programs are entirely defined by their formal, or syntactical, structure.
4) Minds have mental contents; specifically they have semantic contents.

On the basis of the above he offers a number of conclusions but his first is telling: "No computer program by itself is sufficient to give a computer a mind. Programs in short are not minds, and they are not sufficient by themselves for having minds."

While thinking highly of Searle's work, I believe his Chinese Room argument is deeply flawed. I can't offer a full account here for reasons of space, but the point is that, while he has correctly noted that the kind of intelligence we have (and that we might be interested in recreating on a computer) is a conscious intelligence, his argument that computers can never offer a medium for recreating this hinges on a mistake. He says in point #2 that "Syntax is not sufficient for semantics." He amplifies this by noting that this is "a conceptual truth," i.e., it is true by definition. "It just articulates our distinction between what is purely formal and what has content," he adds. But the fact that the two notions are conceptually different does not entail a claim that one type of thing cannot give rise to another.

Searle wants to say that computers can never provide an adequate platform for the phenomena of consciousness on this basis but his argument doesn't demonstrate this. In fact, despite all his efforts with the Chinese Room thought experiment, one can still envision a complex of computer-driven programs that replicate all the various functionalities we find in our own minds which, if combined in the layered and integrated way they are in humans, can presumably yield the kind of consciousness we have. Of course, this is not to say this CAN be done technically, only that Searle's argument that it can't be founders on the meaning of the term "sufficient" that he uses in the second step of his argument. He wants us to accept that though step #2 arises from a purely conceptual claim, it can be construed to have an empirical implication. In this I think he errs.

All of this said, however, I want to add that this is a very fine book. It is concise, clear, and profound in its thinking. Searle is certainly right in his recognition about what "intelligence" is, as far as he takes it, which may be about as far as a philosopher can. The rest is up to the scientific workers in the field, those who are experimenting with and designing new ways to operationalize minds in machines.

SWM

Although the book discusses several classical problems such as the problem of freedom and free will, the mind-body problem, right and wrong, etc., for me the two most interesting chapters were the one on the mind-body problem, and the one on cognitive psychology.

Here Searle proposes a thorough-going biological and physical explanation that, as a neurobiolgist, I've always liked myself.

You really need to read these two chapters to understand all the details, of course, but I'll briefly summarize his idea, and you can decide if it makes sense to you.

Basically, Searle says there really is no mind-body problem. This dichotomy occured because philosophy completely misunderstood the entire issue. There is no mind-body problem, because the mind depends on the brain, and on the neural workings of the brain, and there is no reason even to say that consciousness itself is separate from the brain itself.

Searle points out that we explain the properties of normal matter, such as a steel ball, which has mass, weight, is impenetrable, is magnetic, and so on, by reference to its atomic and molecular properties. There is no reason to posit any intevening layer of "rules" or theory.

It's the same with the mind-body problem. Mind depends on neurons. All our behavior depends on neurons. There is no reason to posit this intermediate entity of consciousness or of mind which is separate from the underlying biology. There is no doubt that consciousness exists, but there's nothing special about it, and although Searle doesn't claim it can be reduced to neural functions yet, he leaves no doubt that classical views about the mind and consciousness are fundamentally flawed.

Anyway, I can certainly sympathize with this point of view, and would like to make a point of my own. I've studied the brain, and when you see people with tiny, focal, strokes in the language area of the brain who have no detectable impairment except they can no longer use articles or conjunctions in their speech, or people with temporal lobe damage who can easily name an object when you show it to them, but who can't tell you its function, and vice versa, where there are people who have temporal lobe damage in an adjacent area with exactly the reverse syndrome--they can tell you what its for but can't name the object--in other words, the naming function and the definition function seem to be separate in the temporal lobe, and the two areas must communicate in order to be able to do both, or at least the information is stored separately and you need access to both--you very quickly get the idea that if it's not in the brain, it's not anywhere. There are legions of other neurological cases where people have lost very specific or general functions depending on the source and extent of the damage to the brain.

Furthermore, it's becoming clearer as a result of research that there is no single part of the brain that gives rise to consciousness. Consciousness relates to different functions located in different parts of the brain being integrated in time through a finely controlled and switched system of neural communications pathways. Thus, consciousness is not a unitary entity at all, although it might seem so to our own introspective minds. More accurately, it is a unified process that occurs through the integration of diverse brain areas and brain functions.

Anyway, Searle's biological reductionism and determism isn't very different from how neuroscientists think, and I give him credit for being willing to discuss the subject in those terms and propose such a radical solution (from the standpoint of most philosophers) to the mind-body problem.