Abstract
Though multiple realization has been an important concept in the philosophy of mind and philosophy of psychology for more than fifty years, it has not been until quite recently that anyone proposed an actual theory of what multiple realization is. This paper argues that the most dominant current theories of multiple realization are unacceptable. It does so by mainly arguing for a particular methodology for theorizing about multiple realization. Rather than being mostly constrained by intuitions, as theorizing about folk notions usually is, theorizing about multiple realization is, it argues, constrained by the theoretical context in which the concept was born. By the lights of this method for constructing theories of multiple realization, these current theories are unacceptable.