[generuso]

It all started with ELIZA. Although Weizenbaum, the author of the chatbot, always emphasized that the program was performing a rather simple manipulation of the input, mostly based on pattern matching and rephrasing, popular press completely overhyped the capabilities of the program, with some serious articles debating whether it would be a good substitute for psychiatrists, etc.

So, many people, including Searle, wanted to push back on reading too much into what the program was doing. This was a completely justified reaction -- ELIZA simply lacked the complexity which is presumably required to implement anything resembling flexible understanding of conversation.

That was the setting. In his original (in)famous article, Searle started with a great question, which went something like: "What is required for a machine to understand anything?"

Unfortunately, instead of trying to sketch out what might be required for understanding, and what kinds of machines would have such facilities (which of course is very hard even now), he went into dazzling the readers with a "shocking" but a rather irrelevant story. This is how stage magicians operate -- they distract a member of the audience with some glaring nonsense, while stuffing their pockets with pigeons and handkerchiefs. That is what Searle did in his article -- "if a Turing Machine were implemented by a living person, the person would not understand a bit of the program that they were running! Oh my God! So shocking!" And yet this distracted just about everyone from the original question. Even now philosophers have two hundred different types of answers to Searle's article!

Although one could and should have explained that ELIZA could not "think" or "understand" -- which was Searle's original motivation, this of course doesn't imply any kind of fundamental principle that no machine could ever think or understand -- after all, many people agree that biological brains are extremely complex, but nevertheless governed by the ordinary physics "machines".

Searle himself was rather evasive regarding what exactly he wanted to say in this regard -- from what I understand, his position has evolved considerably over the years in response to criticism, but he avoided stating this clearly. In later years he was willing to admit that brains were machines, and that such machines could think and understand, but somehow he still believed that man-made computers could never implement a virtual brain.