Herbert writes Dune Messiah as a semi-historical, semi-fictional text, beginning the novel with a third-person reflection on Paul's reign as Muad'Dib. The writing style is not entirely objective or factual, as a more academic text might be. Herbert includes the subjective elements that feature widely in fiction—hyperbolic statements, pathos, and figurative language. These stylistic shifts, from personal musings to more impersonal, historical accounts, are subtle. As such, Dune Messiah does not feel like a piecemeal, discontinuous narrative.
On a stylistic level, Herbert uses epigraphs to achieve this stylistic variation without compelling feelings of discontinuity in the reader. While discontinuous style may be useful in other works, it would not serve Herbert's purpose in Dune Messiah. Herbert switches from the historical to the personal through strict delineations, separating these subtly variable styles of writing into separate chapters, or into a historical epigraph that contextualizes a more personal chapter.
The success of Dune Messiah lies in its ability to transverse narrative perspectives, something that would not be entirely possible without variations in style. Historians speak differently than do writers of personal narrative or memoir. To capture both the personal and the anthropological aspects of his world-building, Herbert must capture both means of speaking—of writing.