 Shapiro’s dilemma is in the spirit of an earlier “causal powers” argument from Jaegwon Kim (1992) Kim insists that scientific kinds are individuated by their causal powers, and the causal powers of each instance of some realized kind are identical to those of its realizer. From these principles it follows that instances of a mental kind with different physical realizations are distinct kinds because of the distinct causal powers of their realizers. A structure-independent mental kind is not a causal kind, and hence is disqualified as proper scientific kinds. Multiple realizability yields the failure of structure-independent mental kinds to meet a standard of what makes something a scientific kind.