I think Chris is right, and the Silk/Horn problem is central to the debate of the soul, the mind-body problem (which is different because we have already ruled out, thank gooness, Descartes), and identity.

Silk/Horn is a more complex of Severian's own identity "crisis", (I don't konw if any situations like this is in Cerebus or Latro), but I think Severian's acquisition of extra personae has anything to do with the part of our debate that concerns the soul, and here's why.

With Severians acquisition of Thecla's
 Both are examples of communion, though one is profane and the other well if not exactly sacred as in communing with God, it is certainly not evil. I don't think there is anything "mystical" about it, how a drug and a bit of muscle tissue transfer memories or even eating a piece of neocortex is unclear, and how that effects Severian's neurophyisology is unclear, but Wolfe is writing creative neuroscience; however, I think it's safe to assume he means that they are downloading mindware, not only narrative memories but also cognitive processes and sensory memory, which minds he is downloading in full or in part of the model of that person's entire mind.  f Wolfe fails to mention a change in Severian's neural pathways or how it is supported within his body, that's understandable, but I definitely think we are meant to see this as a biological if fantastic process.

In the same way I don't think Marble is sharing a body with Rose.  It seems rose had a secondary memory storage, a harddrive, if you will which Marble acquired in a physical way, a way that is similar to Severian ingesting the flesh of Thecla and the Autarch.  these events in many ways are scientistic if not scientific, they involve hardware or meatware.  I would argue the same for Auk and Chenille's possession by the god's.  Of this class, I am not sure which of these cases is the most complex or represnetative of what Wolfe is trying to say.

Severians "ressurection", however, is of the same type as Silk/Horn and the Inhumi.  I think of this class, it is fairly obvious Silk/Horn is the most important case.

As far as the "complex" and "simple" views are concerned, I think the first class if complex and the second simple.  We would call them instead the dynamic and static self, though this isn't very desciptive either.  Here is a question.  Descartes believed the soul is an "object" outside of time and space which somehow corresponds to consciousness and is interact with the meat world.  This is of course logically impossible.  However, for Wolfe it does not seem the soul is the mind, otherwise why the distinction between the cases we've looked at, if of course, you think the the distinction is valid.  However, does Wolfe think of the soul outside of time? 

The reason I say this is because for medieval Catholicism, and this is translating it into our terms today,it seems the soul is an object inside time and space corresponding to the mind and emotions supported by an unknown energy structure called "spirit" which supports these processes of cognition etc after bodily death but in a different way, since incarnation means you are subject to certain changes in emotions and cognition due to changes in your body.

In the same way does Wolfe treat the soul at any time treat informational singularity? I am not sure how Wolfe if he does, reconcile the complex view with the static view or even tries to present a discourse on the simple view in the same way as he has with the complex one.