 The multiple-occupancy view is usually combined with the general metaphysical claim that people and other persisting things are composed of temporal parts (often called “four-dimensionalism”; see Heller 1990: ch. 1, Hudson 2001, Sider 2001a, Olson 2007: ch. 5). For each person, there is such a thing as her first half: an entity just like the person only briefer, like the first half of a meeting. On this account, the multiple-occupancy view is that Lefty and Righty coincide before the operation by sharing their pre-operative temporal parts or “stages”, and diverge later by having different temporal parts located afterwards. They are like two roads that coincide for a stretch and then fork, sharing some of their spatial parts but not others. At the places where the roads overlap, they are just like one road. Likewise, the idea goes, at the times before the operation when Lefty and Righty share their temporal parts, they are just like one person. Even they themselves can’t tell that they are two. Whether we really are composed of temporal parts, however, is disputed. (Its consequences are explored further in section 8.)