 Copeland discusses the simulation / duplication distinction in connection with the Brain Simulator Reply. He argues that Searle correctly notes that one cannot infer from X simulates Y, and Y has property P, to the conclusion that therefore X has Y’s property P for arbitrary P. But Copeland claims that Searle himself commits the simulation fallacy in extending the CR argument from traditional AI to apply against computationalism. The contrapositive of the inference is logically equivalent – X simulates Y, X does not have P therefore Y does not – where P is understands Chinese. The faulty step is: the CR operator S simulates a neural net N, it is not the case that S understands Chinese, therefore it is not the case that N understands Chinese. Copeland also notes results by Siegelmann and Sontag (1994) showing that some connectionist networks cannot be simulated by a universal Turing Machine (in particular, where connection weights are real numbers).