In a message dated 1/13/2012 6:33:26 A.M. UTC-02, donalmcevoyuk@xxxxxxxxxxx writes: Some sort of 'functionalism' is what I took to underpin Turing's 'Imaginary Game', though his is a tendentious rather than explicit way of proposing a functionalist approach. (Perhaps we should turn to 'functionalism' as a topic, pro and con. As Grice defends it, JLS would have a stake in the game.) This below may help. Cheers, Speranza begin quoted text: _http://en.wikipedia.org/wiki/Functionalism_(philosophy_of_mind_ (http://en.wikipedia.org/wiki/Functionalism_(philosophy_of_mind) ) Types of functionalism [_edit_ (http://en.wikipedia.org/w/index.php?title=Functionalism_(philosophy_of_mind)&action=edit§ion=3) ] Machine-state functionalism (http://en.wikipedia.org/wiki/File:Maquina.png) (http://en.wikipedia.org/wiki/File:Maquina.png) Artistic representation of a _Turing machine_ (http://en.wikipedia.org/wiki/Turing_machine) . The broad position of "functionalism" can be articulated in many different varieties. The first formulation of a functionalist theory of mind was put forth by _Hilary Putnam_ (http://en.wikipedia.org/wiki/Hilary_Putnam) .__ (http://en.wikipedia.org/wiki/Functionalism_(philosophy_of_mind)#cite_note-Putnam1960-4) __ (http://en.wikipedia.org/wiki/Functionalism_(philosophy_of_mind)#cite_note-Putnam1967-5) This formulation, which is now called machine-state functionalism, or just machine functionalism, was inspired by the analogies which Putnam and others noted between the _mind_ (http://en.wikipedia.org/wiki/Mind) and the theoretical "machines" or computers capable of computing any given _algorithm_ (http://en.wikipedia.org/wiki/Algorithm) which were developed by _Alan Turing_ (http://en.wikipedia.org/wiki/Alan_Turing) (called _Universal Turing machines_ (http://en.wikipedia.org/wiki/Universal_Turing_machine) ). In non-technical terms, a Turing machine can be visualized as an indefinitely and infinitely long tape divided into rectangles (the memory) with a box-shaped scanning device that sits over and scans one component of the memory at a time. Each unit is either blank (B) or has a 1 written on it. These are the inputs to the machine. The possible outputs are: * Halt: Do nothing. * R: move one square to the right. * L: move one square to the left. * B: erase whatever is on the square. * 1: erase whatever is on the square and print a '1. An extremely simple example of a Turing machine which writes out the sequence '111' after scanning three blank squares and then stops is specified by the following machine table: State One State Two State Three B write 1; stay in state 1 write 1; stay in state 2 write 1; stay in state 3 1 go right; go to state 2 go right; go to state 3 [halt] This table states that if the machine is in state one and scans a blank square (B), it will print a 1 and remain in state one. If it is in state one and reads a 1, it will move one square to the right and also go into state two. If it is in state two and reads a B, it will print a 1 and stay in state two. If it is in state two and reads a 1, it will move one square to the right and go into state three. If it is in state three and reads a B, it prints a 1 and remains in state three. Finally, if it is in state three and reads a 1, then it will stay in state three. The essential point to consider here is the nature of the states of the Turing machine. Each state can be defined exclusively in terms of its relations to the other states as well as inputs and outputs. State one, for example, is simply the state in which the machine, if it reads a B, writes a 1 and stays in that state, and in which, if it reads a 1, it moves one square to the right and goes into a different state. This is the functional definition of state one; it is its causal role in the overall system. The details of how it accomplishes what it accomplishes and of its material constitution are completely irrelevant. According to machine-state functionalism, the nature of a mental state is just like the nature of the automaton states described above. Just as state one simply is the state in which, given an input B, such and such happens, so being in pain is the state which disposes one to cry "ouch", become distracted, wonder what the cause is, and so forth. -- end quoted text.