  It is clear that spatiotemporal relations play a critical role in Lewis's conception. However, it is important to note that Lewis understands such relations in a very broad and flexible way so as to allow, in particular, for the possibility of spirits and other entities that are typically thought of as non-spatial; so long as they are located in time, Lewis writes, “that is good enough” (ibid., 73). So with this caveat, let us say that that an object a is connected if any two of its parts bear some spatiotemporal relation to each other,[14] and that a is maximal if none of its parts is spatiotemporally related to anything that is not also one of its parts. Then we have the following concretist answers to our questions: 