What''s computation? The received answer is that computation is a computer at work, and a computer at work is that which can be modelled as a Turing machine at work. Unfortunately, as John Searle has recently argued, and as others have agreed, the received answer appears to imply that AI and Cog Sci are a royal waste of time. The argument here is alarmingly simple: AI and Cog Sci (of the
Strong
sort, anyway) are committed to the view that cognition is computation (or brains are computers); but
all processes are computations (or
all physical things are computers); so AI and Cog Sci are positively silly.
I refute this argument herein, in part by defining the locutions
x is a computer
and
c is a computation
in a way that blocks Searle''s argument but exploits the hard-to-deny link between What''s Computation? and the theory of computation. However, I also provide, at the end of this essay, an argument which, it seems to me, implies not that AI and Cog Sci are silly, but that they''re based on a form of computation that is well
beneath
human persons.
Key words Computation - Turing Machines - Computer(s) - infinitary reasoning - Artificial Intelligence - Cognitive Science - automata
I''m greatly indebted to the following people, whose trenchant comments and objections made this paper appreciably better (but perhaps no more agreeable to them!): Stevan Harnad (whose administrative toil in coordinating this entire multi-player project is also much appreciated), David Israel, David Chalmers, Michael Dyer, Bill Patterson, and a number of anonymous, clever and feisty referees whose objections are rebutted in what follows (sometimes in footnotes). Of course, I''m in general indebted toall participants in the skywriting What''s Computation? forum. Despite all the help, the errors herein aremy errors; and, in particular, for weal or woe, (D3) is my definition. Lastly, I''m greatly indebted to john Searle, whose seminal reasoning drives this essay.