 Inquiry into the constituents or “stuff” of the social world, discussed in the last section, is a huge field. But there is another field of inquiry with an array of approaches in social ontology: the inquiry into how social categories or kinds are set up. Consider, for instance, the fact Kanye and Kim are dancing the cha-cha. The “stuff” of the dance is the two people moving around in some pattern. But, we might ask, what sets up the category cha-cha? Why do the moves determine what dance it is, rather than the material of floor they are dancing on or the brand of shoes they are wearing? What makes it the case that dances are categorized into cha-chas versus sambas versus salsas; or, for that matter, certain sequences of movement into dances versus strolls versus marches?