This paper argues for including stuff in one's ontology. The distinction between things and stuff is first clarified, and then three different ontologies of the physical universe are spelled out: a pure thing ontology, a pure stuff ontology, and a mixed ontology of both things and stuff. Eleven different reasons for including stuff in one's ontology are given. Then five objections to positing stuff are considered and rejected.

I examine the implications of positing stuff as a way to avoid colocation in the case of the statue and the bronze that constitutes it. When characterising stuff, it’s intuitive to say we often individuate stuff kinds by appealing to things and their relations. I argue that if this intuition is correct, there are important restrictions on how we can characterise stuff in order to avoid colocated portions of stuff.

One might well wonder—is there a category under which every thing falls? Offering an informative account of such a category is no easy task. For nothing would distinguish things that fall under it from those that don’t—there being, after all, none of the latter. It seems hard, then, to say much about any fully general category; and it would appear to do no carving or categorizing or dividing at all. Nonetheless there are candidates for such a fully general office, including (...) thing, being, entity, item, existent, and—especially—object.[ It is not obvious that there is any fully general category (whether object or otherwise). Accordingly, not all accounts of object assign it to a fully general category, instead allowing that there are non-objects. On those views, object does indeed divide. Accounts of object, then, differ with respect to whether there are non-objects. And this is not the only fault line. Other dimensions of difference include what objects there are and what objects are. Accordingly, this entry will survey three broad questions about the category object: What, if any, is its contrast or complement? What is its extension? What is its nature? (shrink)