Jonathan Russell Clark at The Millions:
Epigraphs, despite what my young mind believed, are more than mere pontification. Writers don’t use them to boast. They are less like some wine and entrée pairing and more like the first lesson in a long class. Writers must teach a reader how to read their book. They must instruct the tone, the pace, the ostensible project of a given work. An epigraph is an opportunity to situate a novel, a story, or an essay, and, more importantly, to orient the reader to the book’s intentions.
To demonstrate the multiple uses of the epigraph, I’d like to discuss a few salient examples. But I’m going to shy away from the classic epigraphs we all know, those of Hemingway, Tolstoy, etc., the kinds regularly found in lists with titles like “The 15 Greatest Epigraphs of All Time,” and talk about some recent books, since those are the ones that have excited (and, in some cases, confounded) me enough to write about the subject in the first place.
A good epigraph establishes the theme, but when it works best it does more than this.