Instituut voor Taal- en Kennistechnologie
Institute for Language Technology and Artificial Intelligence
Powers's VTTT (Virtual TTT) is no TTT at all: just another TT, a
symbols-only oracle. But if I assume that Powers does not mean to
invoke Dyer's and McDermott's Cheshire cat with this example, but only
the possibility that, in principle, a simulated robot in a simulated
world, simulated by a sufficiently ingenious (very near omniscient)
modeller, who had successfully anticipated and encoded everything that
was relevant in both, could come up with the complete blueprint from
which to build a real TTT-passing robot through virtual-world
testing alone, then I don't disagree, though this seems just about as
likely as Bringsjord's pongid poetry (and Powers seems to agree). But
even then it would certainly not be just a matter of ``unplugging''
the virtual robot from its virtual world and ``replugging'' it into
the real world (as Powers seems to suggest): if in doubt, try this
first with virtual planets in a virtual cosmos.
And it would still only be the real TTT robot, successfully built from
the principles learned from the VTTT, that was grounded. Virtual
grounding is not grounding any more than virtual transduction is
transduction. The causal connections between symbols and what they are
interpretable as being about must be real. There is no way to break
out of the symbolic circle through mere symbol/symbol connections.
Powers also seems to think Searle can simulate transduction the same
way he can simulate symbol manipulation. I'd like to hear this spelled
out in a concrete case, say, transducing photons. Short of using his
own eyes as add-on peripherals (which would of course be begging the
question -- see my reply to McDermott), the only way I can see to
``reconfigure'' Searle so as to be able to do this would seem to call
for more radical forms of engineering than mere software!