 Call this property P. Further, object o1 is grey at region r1g. What grounds this fact? Not the fact that o1 has P. After all, o2 also has P, but it is not grey at r1g. Not the fact that o1 has P and is exactly located at r1. For it is possible that there be a thing that has P and is exactly located at r1g but is not grey at r1g: this is the case, e.g., in the possible world that results from deleting o1 and putting o2 in its place (without rotating it clockwise or counterclockwise). Thus, in addition to his basic distributional properties, Parsons is apparently forced to treat relations to regions (e.g., being grey at) as being basic as well.