 Dürr, Goldstein, and Zanghì (1992) introduced the term “primitive ontology” for what, according to a physical theory, makes up ordinary physical objects; on the de Broglie-Bohm theory, this is the Bohmian corpuscles. The conception is extended to interpretations of collapse theories by Allori et al. (2008). Primitive ontology is to be distinguished from other ontology, such as the quantum state, that is introduced into the theory to account for the behavior of the primitive ontology. The distinction is meant to be a guide as to how to conceive of the nonprimitive ontology of the theory.