Monday, January 07, 2008

John Searle on the Human Mind and the Nature of Intelligence

An interesting, though brief, defense of mind and soul from the onslaught of rationalist, reductionist models that "computerize" the brain and discard the idea of consciousness. But Searle's concept of "intentionality" still is not sufficient for neuroscience to accept the idea of consciousness.

From Ovi:

Modern rationalists whose paradigm of reality is Descartes’ philosophy and its idea that we are nothing but so much matter extended into space and complicated biological machines are fond of pointing out that our brains are similar to a computer program and that therefore computers are conscious or will soon be. In some way artificial intelligence is superior to human intelligence: quicker, more precise, clearer and so the sooner we become “humbots,” the better. After all, doesn’t a computer beat most of us at chess most of the times? What is never mentioned, or is considered superseded in this kind of reductionism, are the ideas of mind and soul, very well know to the ancients as integral characteristics of human beings.

But we need not go all the way back to Plato, or closer to us, Vico, to find major opponents of this dehumanizing view of the nature of man. There is a contemporary philosopher of language still alive who has dedicated his life to the study of the mind and has become a pioneer in the field of cognitive science. His name is John Searle.

Searle counters what he dubs “strong AI” (Artificial Intelligence) with a famous thought experiment, which he calls the Chinese Room argument. This is how it goes: imagine you find yourself in a room containing an enormous rule book, which allows you to look up Chinese sentences and tells you how to reply to them in Chinese. Through a hole in the wall you are handed a piece of paper with a question written on it in Chinese. Using the rule book, you look up the answer to this question which you write on another piece of paper, in Chinese, and pass through another hole. To the people outside the room you appear to have thorough understanding of the Chinese language, whereas in fact you could perform the required task without understanding a word of it.

Searle argues that the Chinese room is an analogy for so-called artificial intelligence. The rule book is the equivalent of a computer program, which manipulates symbols according to a set of rules, and produces answers. By doing so it can give the appearance of being intelligent. But it is nothing of the sort. A computer model of the mind is not actually conscious, just as a computer model of the digestive system cannot actually eat pizza. A computer model of falling in love or reading a novel or getting drunk does not actually experience these things, but simply produces a simulation of these processes. The basic ingredient that distinguishes human minds from computers, according to Searle, is intentionality. Computers are defined syntactically, in terms of formal symbol manipulation, and that, he argues, is insufficient to imply consciousness.

So if consciousness is not something that can be experienced by a computer, what is it exactly and how does it emerge? In his theories about the mind and consciousness, Searle rejects Cartesian dualism—that the mind is something non-physical and separate from the body. He also rejects the reductionism of thinkers such as Daniel Dennet, who believe that consciousness can be reduced to a series of physical processes in the brain similar to a software program.

Instead Searle adopts a position which he call biological naturalism. As per this view, consciousness is an emergent phenomenon of the brain. To explain what he means by this, he cites as an analogy the liquidity, or wetness, of water as being an emergent phenomenon brought about by the behavior of the molecules that it is composed of. You cannot pinpoint a particular molecule and say “this one is wet”—the wetness is a feature of the whole system of molecules. In the same way, one cannot point to a neuron and say “this one is conscious.” Consciousness emerges as a result of the whole system. Events at the micro-level—perhaps at the level of individual neurons—causes a phenonmenon, which we call consciousness, at the macro-level.

Some have seen biological naturalism as a form of dualism since micro-level properties can be objectively studied by a brain surgeon. But the brain surgeon cannot in the same way access macro-level properties such as pain, desire, joy. Searle rejects this suggestion. He stresses that consciousness is a type of physical property; it is not something separate like a kind of juice that is squirted out by the neurons, it is the state that the system is in, part of that system and inseparable from it. How it works—how micro-level behavior creates consciousness at the macro level—is a question for the neuroscientists. But as a problem for philosophers, Searle regards it as solved.

His philosophy solves it by intentionality which is the attachment of meaning to an object, such as a belief about it, possession of it or contempt towards it. In his Collective Intentions and Actions, Searle seeks to show how intentionality can operate on the collective level. He contends that collective intentional behavior exists and is not the same as the sum of individual intentional behavior. Vico called it “common sense” while Jung calls it “the collective unconscious,” but Seale insists that there is no such thing as group mind or group consciousness; society consists of individuals. In this there are clear parallels with his theories of mind and his rejection of dualism and reductionism as explanations of consciousness.

In his The Construction of Social Reality (1996), Searle applies his theory of intentionality to society, looking at the way certain aspects of our world are created as a result of the combined intentionality of those who make use of them. We assign functions to physical objects—turning matter into chairs, money, swimming pools and countries, for example—by our common intention to treat objects in that way, and by our willingness to conform to rules for the treatment of those objects.

Other essential readings for an in depth study of Searle’s theories are Speech Acts: an Essay in the Philosophy of Language (1969), Minds, Brains and Programs (1980), Intentionality: an Essay in the Philosophy of Mind (1983).


Merlin Donald is attacking this issue from the realm of neuroscience itself, and therefore makes a stronger case. You can check out a selection of his articles online (all are PDF format).

More on this, and on Donald's viewpoint when I have more time.


2 comments:

Anonymous said...

You may find interesting another review on Construction of Social Reality by John Searle

http://sensit.wordpress.com/2009/12/04/construction-of-social-reality-by-john-searle/

william harryman said...

Cool - thanks for the link. I'm looking forward to Searle's new book on the social construction of reality, http://27mv.sl.pt