 Graphic unity. At the concrete perceptual level, recent accounts emphasize the role of visual representations in the sciences and suggest what may be called graphic unification of the sciences. Their cognitive roles, methodological and rhetorical, include establishing and disseminating facts and their so-called virtual witnessing, revealing empirical relations, testing their fit with available patterns of more abstract theoretical relations (theoretical integration), suggesting new ones, aiding in computations, serving as aesthetic devices, etc. But these uses are not homogeneous across different sciences and make visible disciplinary differences. We may equally speak of graphic pluralism.  The rates in the use of diagrams in research publications appear to vary along the hard-soft axis of pyramidal hierarchy, from physics, chemistry, biology, psychology, economics and sociology and political science (Smith et al. 2000): the highest use can be found in physics, intuitively identified by the highest degree of hardness understood as consensus, codification, theoretical integration and factual stability to highest interpretive and instability of results. Similarly, the same variation occurs among sub-disciplines within each discipline. The kinds of images and their contents also vary across disciplines and within disciplines, ranging from hand-made images of particular specimens to hand-made or mechanically generated images of particulars standing in for types, to schematic images of geometric patterns in space or time, or to abstract diagrams representing quantitative relations. Importantly, graphic tools circulate like other cognitive tools between areas of research that they in turn connect (Galison 1997, Daston and Galison 2007, Lopes 2009; see also Lynch and Woolgar 1990; Baigrie 1996; Jones and Galison 1998; Galison 1997; Cat 2001, 2013 and 2014; and Kaiser 2005).