Unintentional Multiple Personality: Novels have had characters who are writers with multiple personality, but has this ever been done intentionally?

Most of the multiple personality of characters in novels—switches in personality, memory gaps, hearing voices of alternate personalities, etc.—is unintentional and gratuitous, as indicated by three things:

1. It is not a consistent feature of character development.

2. It is not integral to the plot.

3. No narrator or character explicitly acknowledges its presence.

An example of this is the novelist with multiple personality in Graham Greene’s The Third Man, which I discussed in a past post.

When multiple personality in a novel is unintentional and gratuitous, its only reason for its being in the novel is that the author had thought of it as ordinary psychology. And only a person who has multiple personality, but does not think of it in those terms, would consider its signs and symptoms as ordinary psychology. Thus, gratuitous multiple personality in a novel is evidence of the author’s multiple personality.

If a character’s multiple personality appears unintentional, since no narrator or character recognizes it as such, but it is integral to the plot, then I call it unacknowledged multiple personality. So there are two types of unintentional multiple personality, gratuitous and unacknowledged, both of which are circumstantial evidence of the author’s multiple personality.

All the above is to introduce the following question: Do you know of any novel with a character who is a writer with multiple personality in which the multiple personality is clearly intentional (explicitly acknowledged by a narrator or character, and integral to character development and plot)? I don’t.

If you do know of any such novel, or have any thoughts about unintentional multiple personality, please submit your comment.