Oh, I haven't realized that the name of the book wasn't in English! It's "Des destinées de l’âme", which translates to "Of the fates of soul".

From what I've gathered it's a writer/poet/actor striken by grief who ponders about what happens after death, and about the notion of a soul, both historically (he seems to be speaking a bit about hinduism and greco-roman conceptions of a soul), philosophically, and theologically.

While this still doesn't justify the initial act of using someone skins, knowing the title in french makes it clear that there is a posthumous thematic, I haven't realized that it may not be obvious to non-french speakers.