In Chapter 1, Thackeray introduces the reader to the two main characters of his novel: Becky Sharp and Amelia Sedley. When introducing Amelia, he uses a combination of hyperbole and satire to describe her and establish her as a foil to Becky:
But as we are to see a great deal of Amelia, there is no harm in saying at the outset of our acquaintance, that she was one of the best and dearest creatures that ever lived; and a great mercy it is, both in life and in novels, which (and the latter especially) abound in villains of the most sombre sort, that we are to have for a constant companion, so guileless and good-natured a person.
These first few lines of description are an exercise in overstatement, as Thackeray carefully sets his reader up for Becky and Amelia's dueling narratives. From the start, Amelia seems to be a paragon of virtue—by describing her as utterly "guileless" and "one of the dearest creatures that ever lived," Thackeray uses hyperbole to distinguish Amelia from the other residents of the Vanity Fair. He even primes the reader for the drama to come, pointedly contrasting Amelia with the countless "villains of the most sombre sort" that abound in novels just like this one. Though he doesn't say it outright, Thackeray is plainly alluding to Becky in this remark. As the reader will soon discover, Amelia is a foil to Becky—and vice versa: where Amelia is good-natured and kind, Becky is a deceitful "young misanthropist," not the least bit "kind or placable." Where Amelia's life collapses at the financial ruin of her father, Becky manipulates her way into the upper stratospheres of London society.
Later in the same sequence of exposition, Thackeray offers the reader a satirical vision of his protagonist, in the negative, when he describes everything that Amelia is not:
As she is not a heroine, there is no need to describe her person; indeed I am afraid that her nose was rather short than otherwise, and her cheeks a great deal too round and red for a heroine; but her face blushed with rosy health, and her lips with the freshest of smiles, and she had a good pair of eyes, which sparkled with the brightest and honestest good-humour, except indeed when they filled with tears, and that was a great deal too often;
The pointed observation that Amelia is "not a heroine," even as Thackeray constructs Amelia to be an embodiment of all that is good in the world, betrays his narrator's distaste for literary convention and Thackeray's vision for a novel with no hero. Thackeray's reliance on Amelia's humble physical description, in order to distinguish Amelia from "heroine"-types, is a careful work of satire—even as he assures the reader that Amelia will be a major subject of the novel, he insists that she does not look the part. In this playful way, Thackeray prepares his reader for a novel that eschews tired archetypes and instead presents a set of deeply flawed and human characters in all their complexity and contradiction.
In Chapter 7, Thackeray paints a portrait of Sir Pitt Crawley and his crumbling neighborhood of Queen's Crawley, London. In a novel full of characters of various degrees of social refinement, Sir Pitt stands out for his utter lack of artifice—and Thackeray wastes no time satirizing the elderly aristocrats rough edges:
Whatever Sir Pitt Crawley’s qualities might be, good or bad, he did not make the least disguise of them. He talked of himself incessantly, sometimes in the coarsest and vulgarest Hampshire accent; sometimes adopting the tone of a man of the world. And so, with injunctions to Miss Sharp to be ready at five in the morning, he bade her good night. “You’ll sleep with Tinker tonight,” he said; “It’s a big bed, and there’s room for two. Lady Crawley died in it. Good night.”
If Becky is a shape-shifting master of disguise, Sir Pitt must be her polar opposite. In this interaction with her, Sir Pitt is a caricature of a crass man of the country—and yet he is, by this point, the highest ranking gentleman the reader has had the pleasure of meeting.
Sir Pitt exists in the novel as proof that being a high-class person is not necessarily the same as having poise or delicate manners; to this extent he serves as a foil to Becky's machinations—if Sir Pitt is the real aristocracy, then Becky's performance of aristocracy comes across as doubly inauthentic.
