A refutation of Penrose's Godelian case against artificial intelligence

Having, as it is generally agreed, failed to destroy the computational conception of mind with the Godelian attack he articulated in his The Emperor's New Mind, Penrose has returned, armed with a more elaborate and more fastidious Godelian case, expressed in Chapters 2 and 3 of his Shadows of the Mind. The core argument in these charters is enthymematic, and when formalized, a remarkable number of technical glitches come to light. Over and above these defects, the argument, at best, is an instance of either the fallacy of denying the antecedent, the fallacy of petitio principii, or the fallacy of equivocation. More recently, writing in response to his critics in the electronic journal Psyche, Penrose has offered a Godelian case designed to improve on the version presented in SOTM. But this version is yet again another failure. In falling prey to the errors we uncover, Penrose's new Godelian case is unmasked as the same confused refrain J. R. Lucas initiated 35 years ago.