ABSTRACT
The contemporary locus classicus of the notion that concrete material reality exhibits mereological structure is Paul Oppenheim and Hilary Putnam's 1958 paper "Unity of Science as a Working Hypothesis". According to fundamental mereology, then, there are no "free ontological lunches" when it comes to composite objects; mereological wholes are not "ontologically innocent"; they exist "over and above" their parts. Schaffer begins his discussion of fundamental mereology by putting forward what he calls a "tiling constraint" on possible answers to the question of fundamental mereology. It is clear that both Priority Monism and Priority Macrophysicalism are variants of a Whole-Priority fundamental mereology; both views take wholes per se to be prior to their parts and thus composed of only inseparable parts. Substantial Priority allows for the possibility of a mixed view in which the fundamental substances are scattered across both the intermediate and atomic mereological levels.
