As a metanovel, or novel within the novel we're reading, An Imperial Affliction also represents the question of “What is authentic and valuable?” (This question ties in with the motif of existenstialism, since questioning authenticity and something's inherent value, say the value of life or morality for example, was a major theme of existentialism.) Questions about authenticity appear throughout the story, as Hazel deconstructs preconceived ideas about cancer patients for instance, but also regarding the authenticity of made-up stories. Starting with the epigraph, which is supposedly taken from the made-up An Imperial Affliction, the reader is forced to ask whether the fact that something is fiction has any bearing on its value.
For Hazel, the characters from An Imperial Affliction clearly hold a great deal of value to her, so much so that learning their fates after the end of the novel, as if they were real people, becomes an obsession. Van Houten, however, doesn't seem to believe much in the value of fiction. He questions its use in his email to Augustus, and he tells Hazel quite unapologetically that the characters simply cease to exist when the novel ends. In Hazel's mind that simply isn't true, and her questioning prompts the reader to ask the same questions about The Fault In Our Stars. If Hazel and Augustus are fictional, do they still have real value? The Author's Note suggests they do, saying that “the idea that made-up stories can matter” is “sort of the foundational assumption of our species.” An Imperial Affliction, therefore, becomes a symbol of the authenticity and value of made-up stories.