One possibility, which we have not yet considered, is that what makes it possible for there to be personal identity across the various Boundary Dissolves we have thus far considered is causal continuity. That is, perhaps whatever changes I undergo, there is an underlying causal connection that makes them mine. This causal connection does not exist between you and me and this is why you and I are different persons. Thus, the Causal Border is another apparent excluder of Open Individualism.