In his 1980 article “Minds, Brains and Programs” John Searle wrote:
” Of course the brain is a digital computer. Since everything is a digital computer, brains are too. The point is that the brain’s causal capacity to produce intentionality cannot consist in its instantiating a computer program, since for any program you like it is possible for something to instantiate that program and still not have any mental states.
Ten years after he wrote (or spake, it was the Presidential Address delivered before the Sixty-fourth Annual Pacific Division Meeting of the American Philosophical Association in Los Angeles):
” The point is not that the claim “The brain is a digital computer” is false. Rather it does not get up to the level of falsehood. It does not have a clear sense. You will have misunderstood my account if you think that I am arguing that it is simply false that the brain is a digital computer. The question “Is the brain a digital computer?” is as ill defined as the questions “Is it an abacus?”, “Is it a book?”, “Is it a set of symbols?”, “Is it a set of mathematical formula?”
Apparently Searle changed his opinion in these ten years, since the statements appear to be directly mutually contradictory. Regarding that aspect I mailed Searle, but he didn't answer. A typical SO reader may think I'm unrealistic in expecting an answer, and indeed in my experience, limited to two cases though, philosophers do not answer critique or admit to errors, but e.g. in my own field of C++ programming the top people such as Bjarne Stroustrup and Andrew Koenig are more than willing to discuss things, admit errors (and collect them in errata lists), and so on, and that's also for a few cases been my experience in the field of physics (e.g. I once pointed out a problem with the description of something in Scientific American's "expert answers" column and they put John Baez on it who just fixed it). So I don't think I was unrealistic. But no answer so far.
Hence I'm asking here:
Did he change his opinion, or is it just that a negation of the meaningless is still meaningless, thus not really contradictory?
What on Earth does or did it mean that “the brain is a digital computer”. Literally it's just nonsense, and that interpretation is compatible with both of Searle's statements. I find it difficult to think of a more meaningful interpretation that is also compatible with both.