Little research has been done on philosophical implications of the middle voice of early Greek and certain non-Western indigenous languages. In particular, the potential of such a medial ontology has yet to be even explored, much less realized, within the context of interdisciplinary studies. As a linguistic structure indicating an ambiguous middle ground between active and passive voices, the middle voice suggests a medial ontology that I develop with reference to Plato's late dialogues. I argue that conceiving interdisciplinarity in medial terms integrates at least some otherwise disparate interdisciplinary approaches, approaches that themselves stem from different disciplinary spheres of influence. Rather than proposing a global theory of interdisciplinarity, this article defends the medial resolution of a tension within interdisciplinary studies between construction and discovery, thereby suggesting an ontological point of departure for the development of such a theory.