Full Idea
In a Turing machine, given any state and input, the machine table specifies an output and the next state. …To have full power the tape must be infinite in at least one direction, and be movable in both directions.
Gist of Idea
A Turing machine, given a state and input, specifies an output and the next state
Source
Ned Block (Troubles with Functionalism [1978], p. 71)
Book Reference
'The Philosophy of Mind', ed/tr. Beakley,B /Ludlow P [MIT 1992], p.71
A Reaction
In retrospect, the proposal that this feeble item should be taken as a model for the glorious complexity and richness of human consciousness doesn't look too plausible.