Vincente & Burns claim to have shown, by the use of systems theory, that instantiations and simulation are the same thing. On the contrary, I think they have shown just how they differ. They also criticize my use of the term "normal action" for its lack of precision. While I agree it is not precise, one should be wary of claiming too much from learning how to explain action only in artificially-constrained domains. We seem to agree, however, that AI is only one among many methods to be used by the Cognitive Scientist.
2. Another intriguing comment that they make is that "'certain constraints of normal action' are not the same as the constraints that usually guide scientific investigation" (para. 4). I agree, and so much the worse for AI as a science if this is the case. I cannot deny that the Disneyland-physics relation is not a well defined one. The point of my paper was to investigate that relation, and its relevance to the AI-cognitive science relation. I like to think that I made at least some progress in that direction, though I do not claim it to be of mathematical precision. I appreciate their efforts to clarify the matter further.
3. Finally, though Vicente and Burns arrive at it by a very different route from mine, I am in basic accord with their conclusion that "AI ALONE cannot be the method for cognitive science" (para. 8, italics added). Though perhaps I have overstated my case somewhat in the hopes of getting people's attention, it is not my intention that everyone should roll closed their keyboard drawers and put forehead to fist for the remainder of their days. I simply think that there are some basic problems in psychology that programming is not equipped to solve, and that some--perhaps much--conceptual analysis is needed at the outset.
Green, C.D. (2000) Is AI the Right Method for Cognitive Science? PSYCOLOQUY 11(061) ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/2000.volume.11/ psyc.00.11.061.ai-cognitive-science.1.green http://www.cogsci.soton.ac.uk/cgi/psyc/newpsy?11.061
Vicente, K.J. & Burns, C.M. (2000) Overcoming the conceptual muddle: A little help from systems theory. PSYCOLOQUY 11(074) ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/2000.volume.11/ psyc.00.11.074.ai-cognitive-science.14.vicente http://www.cogsci.soton.ac.uk/cgi/psyc/newpsy?11.074