6-28 Consciousness can be implemented in a functional system.
. . . is supported by . . .
6-38 Machine functionalism.
The claim (Hilary Putnam, 1967)
A mental state is a machine state. Any system that possesses a
mental life is simply a complex Turing machine (see sidebar, "Turing
Machines") instantiating a certain machine table and thereby
running a program. So a computer, programmed with the correct
machine table, could think. Note: Also, see the "Can automata
think?" arguments on Map 7.
Any system that possesses a mental life is simply a complex Turing Machine instantiating a certain machine table. Each mental state (a thought, e.g.) is actually a machine state that arises in the course of that program. As such, every mental state can only be defined as part of a network of sensory inputs, other mental states, and behavioral outputs. So a computer, programmed with the correct machine table, could think.
The Putnam argument
Hilary Putnam is generally credited with proposing the functionalist
position. He writes: "I propose the hypothesis that pain,
or the state of being in pain, is a functional state of a whole
organism....
I shall assume the notion of a Probabilistic Automaton has been generalized to allow for "sensory inputs," and "motor outputs"--that is, the Machine Table specifies, for every possible combination of a "state" and a complete set of "sensory inputs," an "instruction" which determines the probability of the next "state," and also the probabilities of the "motor outputs." (This replaces the idea of the Machine as printing on a tape.) I shall also assume that the physical realization of the sense organs responsible for the various inputs, and of the motor organs, is specified, but that the "states" and the "inputs" themselves are, as usual, specified only "implicitly"--i.e., by the set of transition probabilities given by the Machine Table....
A Description of S where S is a system, is any true statement to the effect that S possesses distinct states S1, S2 ..., Sn which are related to one another and to the motor outputs and sensory inputs by the transition probabilities given in such-and-such a Machine Table" (H. Putnam, 1967, p. 199).
References
Putnam, Hilary. 1967. The nature of mental states. In The Nature
of Mind, edited by Rosenthal, pp. 197-203. Originally published
as "Psychological predicates" in Art, Mind, and Religion,
edited by W.H. Capitan and D.D. Merill, pp. 37-48.