Minds, Machines and Turing

[Stevan Harnad]

The following paper is available at:
http://www.cogsci.soton.ac.uk/~harnad/Papers/Harnad/harnad00.turing.html

Comments welcome.

Harnad, S. (2001) Minds, Machines and Turing: The Indistinguishability
of Indistinguishables. Journal of Logic, Language, and Information
(special issue on "Alan Turing and Artificial Intelligence")
http://www.cogsci.soton.ac.uk/~harnad/Papers/Harnad/harnad00.turing.html

              MINDS, MACHINES AND TURING: 
              THE INDISTINGUISHABILITY OF INDISTINGUISHABLES 

              Stevan Harnad 
              Department of Electronics and Computer Science 
              University of Southampton 
              Highfield, Southampton 
              SO17 1BJ UNITED KINGDOM 
              harnad at cogsci.soton.ac.uk 
              http://www.cogsci.soton.ac.uk/~harnad/

    ABSTRACT: Turing's celebrated 1950 paper proposes a very general
    methodological criterion for modelling mental function: total
    functional equivalence and indistinguishability. His criterion
    gives rise to a hierarchy of Turing Tests, from subtotal ("toy")
    fragments of our functions (t1), to total symbolic (pen-pal)
    function (T2 -- the standard Turing Test), to total external
    sensorimotor (robotic) function (T3), to total internal
    microfunction (T4), to total indistinguishability in every
    empirically discernible respect (T5). This is a
    "reverse-engineering" hierarchy of (decreasing) empirical
    underdetermination of the theory by the data. Level t1 is clearly
    too underdetermined, T2 is vulnerable to a counterexample (Searle's
    Chinese Room Argument), and T4 and T5 are arbitrarily
    overdetermined. Hence T3 is the appropriate target level for
    cognitive science.  When it is reached, however, there will still
    remain more unanswerable questions than when Physics reaches its
    Grand Unified Theory of Everything (GUTE), because of the mind/body
    problem and the other-minds problem, both of which are inherent in
    this empirical domain, even though Turing hardly mentions them.

    KEYWORDS: cognitive neuroscience, cognitive science, computation,
    computationalism, consciousness, dynamical systems,
    epiphenomenalism, intelligence, machines, mental models, mind/body
    problem, other minds problem, philosophy of science, qualia,
    reverse engineering, robotics, Searle, symbol grounding, theory of
    mind, thinking,Turing, underdetermination, Zombies.