 In addition, both Chalmers (1995, 1996) and Copeland (1996) argue that the mappings invoked by unlimited pancomputationalism violate the counterfactual relations between the computational states, which are required by the counterfactual mapping account, mentioned above. Consider again Putnam’s slice-and-aggregate strategy for generating mappings. The mappings are constructed based on an arbitrary dynamical evolution of an arbitrary physical system. No attempt is made to establish what would happen to the physical system had conditions been different. Chalmers and Copeland argue that this is illegitimate, as a genuine implementation must exhibit the same counterfactual relations that obtain between the computational states. This response lends support to the counterfactual mapping account of computation.