Minds, Machines, and Turing

Abstract

In the 1960s, the philosophers J.R. Lucas and Paul Benacerraf presented arguments against mechanism, the thesis that minds can be simulated by Turing machines. Instead of discussing Turing machines directly, they shift their focus to using Gödel's incompleteness theorems to show that theories of classical first-order logic could not represent minds. They believed that these arguments about logical theories implied that the mechanistic thesis for Turing machines was incorrect. However, I show that their arguments are insufficient to topple the mechanistic thesis for Turing machines. I then present a new argument, focused directly on Turing machines, that seeks to show that mechanism is false. The argument is reminiscent of the halting problem for Turing machines, and it proceeds by inference to the best explanation to demonstrate that actual minds are not Turing-simulatable.