In “Mark Twain’s Notebook,” he says he has an alternate personality whom he knows about indirectly from its different handwriting and mysterious trips.

In this seventeenth post on Samuel Clemens (search “Mark Twain”), I quote from his personal notebook.

He says that he has—and assumes that everyone may have—three kinds of personalities: his regular self, his double, and his spiritualized or dream self.

His regular self and his double have no direct awareness of each other; they are not co-conscious. He evidently knows about his double from writing that nobody else could have written (but he doesn’t remember writing it), which has handwriting different from his own. And he has evidently been told that he makes trips—that is, someone looking exactly like him, his “double,” has been seen at various places—which he does not recall. These mysterious trips are dissociative fugues, a symptom of multiple personality, discussed in previous posts (search “fugue”).

In contrast, his regular self and spiritualized or dream self are directly aware of each other; they are co-conscious and have a common memory.

Mark Twain’s Notebook

“The two persons in a man do not even know each other and are not aware of each other’s existence, never heard of each other—have never even suspected each other’s existence.

“And so, I was wrong in the beginning; that other person is not one’s conscience…

“I am not acquainted with my double, my partner in duality, the other and wholly independent personage who resides in me—and whom I will call Watson, for I don’t know his name, although he most certainly has one, and signs it in a hand which has no resemblance to mine when he takes possession of our partnership body and goes off on mysterious trips—but I am acquainted (dimly) with my spiritualized self and I know that it and I are one, because we have a common memory…my dream self…” (1, pp. 349-350).

1. Mark Twain. Mark Twain’s Notebook. Foreword by Albert Bigelow Paine. New York, Harper and Brothers, 1935.