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Source:Rediscovering the Book of Mormon:Ch:6:1:Multiple small plate authors
The writings of Jacob and his descendants form part of the small plates, a section of the Book of Mormon that Mormon included intact, presumably without editing. Only on the small plates may Joseph Smith have found someone's "handwriting" other than that of Mormon or Moroni. Speaking in the first person, Jacob and his descendants seem more individual, even in translation, than other writers whose words were more obviously edited by Mormon and Moroni. From Jacob through Omni, the record displays the complex variety one expects of a text written by many hands. The stylistic diversity of Jacob and his descendants is a powerful witness that we are dealing with material written by several ancient authors rather than by one person in early nineteenth-century New York.
Consider, for example, the transition between Omni and the Words of Mormon. It has the rough edges we would expect to find in a bridge between an unedited text and an edited abridgment. At this point in the book, Mormon explains for his readers a number of puzzling pieces that would make up his record. He discusses two different civilizations (the Nephites and Mulekites), two separate time frames (Mosiah's and Mormon's), and three groups of records (the small plates, the large plates, and his abridgment of the large plates). Mormon also mentions a fourth set of records (the brass plates) as he introduces the Book of Mosiah (see 1:3).
To make matters more confusing, just before Mormon's bridge, Amaleki in the Book of Omni records two dramatic episodes of cultural contact involving several major Book of Mormon civilizations. Amaleki first tells of an encounter between Nephites from the land of Nephi and Mulekites in the land of Zarahemla. This is our first introduction to a group that left Jerusalem at roughly the same time as did the Lehite group, about 586 B.C. (see Omni 1:13-19). Amaleki then recounts the Mulekites' prior contact with Coriantumr, the last survivor of yet another, even more ancient civilization about whom we've also heard nothing till this reference, but whose history will be given later (see Ether).
Thus in a few pages, the text refers to events happening across 2500 years of history and relating to every major Book of Mormon group. It does so, moreover, in a way that requires specific knowledge of how each civilization began and how it would end. No wonder that, despite Mormon's best efforts to smooth the transition, readers often find it difficult to understand how the parts fit together. In order to make full sense of these few pages from Omni to Mosiah, the reader (and writer) has to know Book of Mormon history from the coming of the Jaredites to the demise of the Nephites (not to mention the story of the lost 116 pages).Yet Mormon makes the transition flawlessly—at least with respect to historical details. The transition is rougher with respect to style. The style of the small plates (Omni and before) is different from the style of Mormon's bridge (Words of Mormon) and of his abridgment of the large plates (Mosiah and after). These rough edges provide strong evidence that this part of the Book of Mormon is precisely what it claims to be: namely, a first-person document that is being spliced into a larger history by someone who knows the full story to come.