Except for an early brief foray into the other camp (Oppenheim and Putnam 1958) Hilary Putnam has been pretty steadfastly an anti-reductionist at least in so far as the non-mathematical sciences are concerned. As his views have changed over time, however, there has been a shift in the target of his anti-reductionism. In his earlier work (prior to his adoption of an “internal realist” or “pragmatist” perspective) he seemed prepared to defend a realist and broadly materialist (but anti-reductionist) conception of empirical inquiry and its subject matters. With the turn to internal realism or pragmatism he appears to have rejected the viability of a genuinely nonreductionist version of metaphysical materialism, or indeed of any realist metaphysical position. At least as early as “Why there isn’t a Ready Made World” (Putnam 1983b) and as recently as Ethics Without Ontology (Putnam 2004) Putnam appears to maintain that genuinely metaphysical realist positions are inevitably (and mistakenly) reductionist and are to be rejected in favor of a broadly pragmatist or Wittgensteinian conception. It is with this and related antirealist claims that I propose to take issue here.