 In closing this section, it should be clear that the extension of philosophical discussions about multiple realization, which began with the “second-wave” of criticisms around the year 2000, continues apace. The specific philosophical arena in which these discussions take place continues to expand, from the topic’s origins in mid-twentieth century philosophy of mind through its turn-of-the millennium path into the philosophy of the cognitive sciences and neuroscience, and lately more squarely in the general metaphysics of science. These shifts can make the details of the evolving discussions difficult to track. Polger and Shapiro’s (2016) book, and the critical scrutiny across all of these fields that it spurred, provides a useful framework for organizing these many directions, despite what one judges about its skepticism about the extent of multiple realization and its defense of a mind-brain identity theory. The literature over the last twenty years should put to rest the still-too-prominent view in the philosophy of mind that multiple realization spells doom for reductive materialism and mind-brain identity theory once and for all, as well as the still-too-prominent view in some quarters in philosophy of science that multiple realization, or at least its anti-reductionist consequences, has been vanquished for good. Both views look uninformed and badly outdated in light of the detailed history of multiple realization, a history which now spans more than a half-century of Anglo-American philosophy.