Multiple Ontologies in Pain Management: Toward a Postplural Rhetoric of Science S. Scott Graham University of Wisconsin–Milwaukee Carl Herndl University of South Florida This article uses data obtained from a 2-year study—observation, survey, written- and verbal-artifact analysis, and interviews—of an interdisciplinary organization of pain management professionals to illustrate the analytic advantages of Mol and Latour’s multiple-ontologies theories over incommensur- ability theory in understanding interdisciplinary practice. We demonstrate that pain science and medi- cine encompass a variety of practices that transcend disciplinary boundaries in ways not accounted for with incommensurability theory. After explicating multiple ontology theory and illustrating its ana- lytic potential, we conclude by recommending a postplural model for inquiry into rhetoric of science. Keywords: incommensurability, medical rhetoric, postplural science studies, theory of multiple ontologies In short, science is a rollicking Feyerabendian, Protagorean epistemic carnival, in which incommen- surability—misaligned meanings, practices, and values in situations of reciprocal hostility—helps to keep the various groups agitated. (Harris, 2005a, p. 109) Ontology in medical practice is bound to a specific site and situation. In a single medical building there are many different atheroscleroses. And yet the building isn’t divided into wings with doors that never get opened. The different forms of knowledge aren’t divided into paradigms that are closed off from one another. It is one of the great miracles of hospital life: there are different atheroscleroses in the hospital but despite the differences between them they are connected. (Mol, 2002, p. 55) These two epigraphs juxtapose different accounts of the nature of theoretical conflict in the sciences. The first, from incommensurability studies, should be familiar to rhetoricians. It offers a broad and all-encompassing encapsulation of the detrimental effects that can arise from conflicting epistemologies in science. The second, from a philosopher of science and medicine, presents an ontological model of difference located in specific sites of praxis. However, Mol’s (2002) account of this ontological difference does not create the same kind of cross-theoretical conflict that arises in Harris’s (2005a) epistemic carnival. Although the first is more familiar to rhetoricians, the second is representative of much recent empirical inquiry into the problems of communication and cooperation across difference in science and technology studies (STS) and, we believe, offers a productive alternative to theories of incommensurability. Technical Communication Quarterly, 22: 103–125, 2013 Copyright # Association of Teachers of Technical Writing ISSN: 1057-2252 print/1542-7625 online DOI: 10.1080/10572252.2013.733674