 Lewis’s original response also underlies Jaegwon Kim’s (1989, 1992) appeals to structure-specific “local reductions”. Kim agrees that multiple realizability rules out a general reduction of (structure-independent) psychology to some physical science. But it permits, and even sanctions, a local reduction of psychology to a theory of the physical mechanisms of given structure-types. (Kim admits that the relevant structure-types here will probably be narrower than biological species.) Local reductions involve “structure-specific bridge laws” where the mental-physical biconditional occurs as the consequent of a conditional whose antecedent denotes a specific structure-type (e.g., “if X is a member of structure type S, then X is in mental state M if and only if X is in physical state P”). Conditionals whose antecedents denote different structure types will typically have biconditionals as consequents whose mental term-constituents are co-referential but whose physical term-constituents denote different physical events. Multiple realizability forces this much revision to the bridge laws of classical reductionism. But according to Kim, domain-specific local reductions are the rule rather than the exception in science generally, and are sufficient for any reasonable scientific or philosophical purpose.