Does an Adequate Physical Theory Demand a Primitive Ontology?

Configuration space representations have utility in physics but are not generally taken to have ontological significance. We examine one salient reason to think configuration space representations fail to be relevant in determining the fundamental ontology of a physical theory. This is based on a claim due to several authors (Allori, Durr, Goldstein, Tumulka, and Zanghi) that fundamental theories must have primitive ontologies. This claim would, if correct, have broad ramifications for how to read metaphysics from physical theory. We survey ways of understanding the argument for a primitive ontology in order to assess the case against configuration space realism.