In the face of disunification and incommensurability, how can the scientific community maintain itself and (re-)establish commensurability? According to Peter Galison's investigations of twentieth-century microphysics, commensurability is achieved through local coordination even in the absence of global meaning: The "strength and coherence" of science is due to diverse, yet coordinated action in trading zones between theorists and experimenters, experimenters and instrument builders, etc. Galison's claim is confronted with Georg Christoph Lichtenberg's establishment of commensurability between unitarians and dualists in the eighteenth century dispute about electrical fluids. The contrast of cases suggests an alternative account: Commensurability may be established through the global coordination of local meaning. And where Galison reifies the disunification of science, this account suggests a dynamic interplay between de facto disunification and an intended unity. This interplay is manifested in the pervasive and ongoing practical concern for the conditions of successful communication in a science that is constantly in-the-making.