By definition, to talk about personal survival after death is as survival of the same person that was formerly alive. So the question of immortality presupposes the question of personal identity: we need to know what it means to say a person is the same person at a later time (T2) as she was at an earlier time (T1).

The notion of personal identity also underlies memory (a heavenly person will remember her life on earth) and anticipation (an earthly person can anticipate her future in heaven). Gretchen would like to be able to anticipate her own survival after death — not the survival of a Gretchen-copy, "someone who looks and sounds and thinks" just like Gretchen.

We cannot say a person survives if the person’s parts (e.g., the person's atoms or quarks) survive. What's true at the level of atoms isn't necessarily true at the level of bodies. To assume that what's true of the atoms is necessarily true of the bodies they comprise is to commit the fallacy of composition.

"Merger with Being" is not a solution, either, since it does not guarantee personal immortality.

Religious people like Miller talk as though personal immortality is unproblematic. They say, e.g., "We’ll meet in heaven." (Sometimes they even suppose that we’ll meet in heaven with the same bodies we had on earth.)

But surely this is nonsense. Both Miller and Weirob agree that if there is survival after death at all, it must be survival of something other than the body. I take this to be the point of the Box of Kleenex argument (p. 5). What survives must be mind or soul or consciousness. So if there’s personal immortality, personal identity must be identity of soul: we must "have" or "be" the very same soul after death.

Weirob’s main conclusion in this section: that even if disembodied souls exist (which she doubts), "they can by their nature provide no principle of personal identity." (17)

Her arguments:

P1: Souls by definition cannot be sensed in any way. (Miller agrees with this.)

C1: Therefore, there is no way to show that a soul is the same soul from one day to the next, or even from one moment to the next.

P2: Yet we make judgments about personal identity all the time. For example,we don’t hesitate to say we know that "Mom" today is the same person that was around when we were smaller.

C2: (from C1 and P2) Our judgments about personal identity can’t be based on any knowledge of sameness of soul. I.e., even if souls exist, they are irrelevant to judgments of personal identity.

Miller responds to this that bodies are the same from one occasion to the next, and souls don’t just spontaneously leap out of bodies (the"anti-kangaroo principle"). Weirob replies that if P1 is true,the anti-kangaroo principle is groundless.

Miller now tries another tack: we know personal identity through sameness of psychological characteristics, which simply are characteristics of soul. Weirob’s responds that if P1 is true, we cannot equate sameness of psychological characteristics with sameness of soul. Weirob would say sameness of psychological characteristics is caused by sameness of body or brain.

Miller tries a Cartesian argument: "I just know I’m the same soul from one moment to the next."

Gretchen’s answer: you may know you’re the same person, but if P1 is true, you can’t know you’re the same soul. Maybe the soul is occasionally replaced by a psychologically similar one. Maybe it’s constantly replaced; maybe there’s a virtual stream of psychologically-similar souls going through the same body. Maybe a person is the same person in the same way a river is the same river even though the water is never exactly the same.

In summary:

P1: If judgments of personal identity were made on the basis of knowledge of sameness of souls, we wouldn’t be able make such judgments at all, let alone make them with certainty.

P2: We do make them, and with certainty.

C: Judgments of personal identity are not based on knowledge of sameness of souls. Even if souls exist, they are irrelevant to knowledge of personal identity.

I.e., personal identity can’t be identity of soul. It is identity of person.

For Gretchen, "person" means "body," and only "body." And so personal identity is identity of the body.

Thus it is inconceivable that a person could continue to exist as the same person after dissolution of the body.