“The Host” (post 4) by Stephenie Meyer (post 5): In this science fiction version of spirit possession and exorcism, aliens go native and love conquers all. 

The story of this novel—that the protagonist’s alternate personality is an alien being from outer space, who at the end of the novel gets surgically removed, so that the host personality can have her body all to herself—is nothing but a science fiction version of spirit possession and exorcism, which is an obsolete, misunderstanding of a psychological condition, multiple personality.

Nevertheless, there are two reasons to read this novel. First, it is a heartwarming romance in which love conquers all. Second, its depiction of the interaction between the two personalities—their rivalry, communication, and eventual cooperation—is true to life. For some reason, the author knows something about this.

What is not true to life is the idea that you can, or would even want to, eliminate the alternate personality. Since all of a person’s personalities originate from within that person, they are all parts of that person’s total personality. The only longterm solutions to distress or dysfunction are cooperation among the personalities or their merger into one.

Some multiples (people with multiple personality) want merger: all their personalities combined into one multifaceted personality. E Pluribus Unum (from many, one). And if all personalities agree, this is possible.

But some multiples would consider merger murder. And others would consider merger stupid, since multiple personality is key to their life as a novelist. In any case, there is no medicine or therapy than can eliminate personalities or impose merger. Personalities can appear to be eliminated or merged, but they are just lying low.