Refer to the book called A Dialogue On Personal Identity and Immortality by John Perry. Why does Weirob think that on the view of a person that...

The dialog occurs over three nights between Miller and his friend, Weirob. Weirob is dying, and Miller is trying to convince her that her identity can endure after death. Weirob is skeptical.

Miller suggests at the beginning of the second night that the key to Weirob's survival after death lies in memory: identity should be understood as a set of psychological connections -- moments, or experiences, that form a coherent pattern. One example used to explain this concept is the idea of seeing different stretches of the same river: specific places on the river may be different, we are able to mentally connect these experiences and realize that despite their differences they are actually the same river. This is possible through memory. Miller suggests that the possibility of identity (e.g., a whole person made up of individual experiences, bound together into a "pattern" of a human being through memory) existing after death only requires imagining a being in heaven who can "remember" your memories.

Weirob tries to show that this argument is circular, since memories can be false; we can really remember something that we actually experienced in the real world, but we can also think we remembered the experience, or remember it in a different and inaccurate way. How can we be sure the being in heaven with Weirob's memories is remembering them in the right way, e.g., that the memories are true? Miller responds that all we need do is imagine that God can create a being with true memories. But if that is the case, Weirob counters, isn't it possible for God to create many of these beings? Which, in that case, would be the real Weirob? Weirob argues that now the preconditions for identity surviving death involve both the existence of a being in heaven with her true memories, and that God somehow has chosen not to create more than one of these beings. 

I find it difficult to not see these arguments as circular. Identity is based on the principles of truth and uniqueness; that is, the accuracy of our memory of real events, and the singular nature of these memories, here or in heaven. It's not clear what test one could use to determine if either of these conditions can be true.