10. A writer's or speakers choice of words; using different types of words depending on the audience being addressed, the subject being discussed, and the effect or mood trying to be produce:
anecdote
diction
dialogue
verbal

This question can be answered in several ways.  One reason why "Night" was written was to speak to the world about the ordeal of the Holocaust from a survivor's point of view.  I am not sure any History text can effectively relay the horror, atrocity, and terror of The Holocaust any better than Wiesel's work.  One need only read about how he was whipped or the closing lines where he stares in the mirror only to see a corpse staring back to understand the true impact of The Holocaust.  Another reason it was written might have been for Wiesel's own voice to be acknowledged.  Anyone who has endured an trauma on the level of Wiesel's must speak out, must take back what was taken, and use their voice in articulating their narrative.  I am certain that Wiesel must have had a psychological compulsion to pen the book of his experiences.