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On the thermostat, I get the impression McCarthy was being a bit obtuse just to goad Searle a little. What he was illustrating is that simple systems can exhibit apparent intentionality while remaining simple. A steam governor or a thermostat are great examples. Living creatures, like the Aplysia californica snail studied by Eric Kandel, make use of analogously pretty damn simple mechanisms for reasonably sophisticated behaviour. Following this line of research, we've created remarkably effective systems like the 'syntax-only' Google Translate system, and IBM's Watson. The questions posed by Nagel and Searle are interesting ones. Qualia is really difficult to account for - it makes sense for a materialistic system to have 'distinct placeholders' for different experiences, but why should they 'feel like' anything? Precisely because they propose a non-materialistic solution, they're difficult ones to explore - and so it's not really surprising that their own attempt to illustrate their perspective haven't been that convincing to materialists. The Chinese Room thought experiment is only convincing if you start out assuming the only thing that can 'think' is the person doing the card shuffling, which begs the question. See Hofstadter's Metamagical Themas for a good exploration of the argument. If you're interested in sophisticated explanations of conscious experience and semantics from a materialist's perspective, Hofstadter and Sander's 'Surfaces and Essences' and Minsky's 'Society of Mind' and 'Emotion Machine' are great. Dennett's 'Intentional Stance' is also relevant - discussing how we can sensibly talk about material systems as having intention. Bear in mind that dualism is the more 'natural thought' in historical terms, and even hardcore materialists lapse into dualist terms easily. Researchers are rightly suspicious of unexamined assumptions. When it comes to science of the mind we have a history of novel, unnatural thoughts that are also very flawed (like Behaviourism), but critically, materialism (and Behaviourism) have both been productive. One thing you can comfortably say about the progress of science is that at any point we're going to be partly wrong. Materialists are actively investigating and testing ideas, which meets my definition of 'real science'. Even if researchers are wrong on an important point, it doesn't make their work worthless, so you should probably hold back on the character assassination. Brain injury's effect on subjective experience and behaviour suggests to me that pure mechanism is important to experience, which is why materialism is my 'default hypothesis'. If you want to ask hard questions, then go back and look at your assertions. What does 'really doing' semantics entail? How can the 'void' between semantic and syntactic systems be accounted for? Or, if we can't currently explain it, what can we do to investigate it? |
If somebody wanted to produce a real AI, every bit as intelligent as a human, he probably wouldn't go wrong by trying to reproduce in software what Pascal Boyer describes in his book "Religion Explained". http://www.Amazon.com/Religion-Explained-Evolutionary-Origin...
Boyer fails, in my mind, in many ways, but at the very least by not providing a solution to the Frame Problem. The Frame Problem looms very large in all of Boyer's descriptions of folk psychology, and how the human mind works. Yet it is completely unaddressed.
For a good explanation of the Frame Problem, see Daniel Dennett's argument "Cognitive Wheels: The Frame Problem of AI" in chapter 7 of "The Philosophy of Artificial Intelligence". http://www.Amazon.com/Philosophy-Artificial-Intelligence-Oxf... In this article, Dennett is his own worst enemy, in that he proves that AI isn't possible. (Nobody has solved the Frame Problem yet.)