I would have to say that I agree with Searle here. I can see how Turing, in 1950, could have believed that technology would advance enough in 50 year’s time to the point that computer should be able to accurately portray humans by today. Since hindsight is 20-20, Searle does have the upper-hand. It is now 2011, and we can see that Turing’s dream has not materialized. Why?
Turing believed that simply by expand a computer’s memory and processing capabilities, that it would eventually be able to act at the same capacity as a human mind. I believe computers are not capable of acting as the human mind does due to a handicap imposed by their current structure and design. As Searle points out there is something inherent in at least the networked structure of the neurons in the human brain that allow humans to think and learn in a manner that is simply not possible for a computer that functions linearly. Besides that, I am certain that there must be something said for the chemical processes of the brain as well, and how they effect thought and understanding.
I found Searle’s argument, on the other hand, to be fraught with emotion and presupposition and condescending to the scientific community to which his argument was targeted. I think it is particularly difficult to really respond to Searle because he failed to even give a definition of the terms “understanding,” “intentionality,” and “belief” that were so central to his argument. It was my interpretation that his understanding of these terms is as something purely human, and therefore not even worth arguing against. I do agree with Searle, however, on the point that an entity cannot be said to be intelligent in the human sense simply if it passes the Turing test, since it must also be considered by what means it does so.
For instance, it is plausible to consider a web-based bot that can search for real human responses to questions, and by so doing, appear to be human. But, if all the bot is doing is matching appropriate answers to questions, it cannot be said to have a true human understanding, as in a knowledge of language, grammer and how they correlate, and how to derive meaning out of a question.
In short, I believe it is possible for computers to have human intelligence, but not in the current “digital” form that computers exist in. Not until they are restructured to reflect the design of the human brain.