Northanger Abbey was the first novel Jane Austen wrote. It is also the novel most closely related to the novels that influenced her reading, and parodies some of those novels, particularly Anne Radcliffe's Gothic novel The Mysteries of Udolpho. In creating Catherine, the heroine of Northanger Abbey, Austen creates the heroine of a Gothic novel. Both Austen and Catherine portray Catherine's life in heroic terms—Austen humorously, and Catherine seriously, especially when she suspects General Tilney of murdering his wife. Because Austen couches her portrayal of Catherine in irony, Catherine is realistically portrayed as deficient in experience and perception, unlike the heroines of Gothic and romance novels. Catherine fails to recognize the obvious developing relationship between her brother James and her friend Isabella; she fails to recognize Isabella's true nature until long after it has hurt her brother; she accidentally leads John Thorpe into thinking she loves him; and most significantly, she embarrasses herself in front of Henry Tilney when he finds out she suspects his father of murder. While Catherine is an avid reader of novels, she is inexperienced at reading people, and this is what causes many of the problems she encounters. By the end of the novel, she has become a much better judge of character, having learned from her mistakes with Isabella and General Tilney. She is also, perhaps, a bit more cynical about people, as Henry is. Ultimately, it is her integrity and caring nature that win Henry's heart and bring her happiness.
Critics argue over Henry's role in the novel. Some critics criticize Henry for patronizing Catherine, for telling her how to see the world and mocking her naiveté. This criticism is partially accurate. Henry is often amused by Catherine's naïve nature, and playfully guides her to a better understanding, as can be seen during their walk around Beechen Cliff and on the ride to Northanger Abbey. But his behavior, especially when compared to that of the boorish John Thorpe, is always gentle and caring. He adores his sister, Eleanor, and loves his father, although he often disagrees with him. Though less than ten years older than Catherine, Henry is far more perceptive than she. He is probably the most perceptive figure in the novel. Henry has read hundreds of books and, as a clergyman, hundreds of people, and this has given him an understanding of human interaction far superior to that of his friends and relatives.
General Tilney comes the closest of any character to being an antagonist in Northanger Abbey, though that term is too strong to describe his role. When Catherine suspects Tilney of murdering his wife, she perceives him as a villain. In fact, the General's true crimes consist of being too concerned with wealth and finery, and perhaps of robbing Catherine of her imaginative vision of a real Gothic abbey. Tilney is not a storybook villain, or even a villain from a Gothic novel. He is realistic man, a wealth-obsessed real estate developer who gets in the way of his children's happiness. Like John Thorpe, he is given to boasting and preoccupied with himself when he is not meddling in his children's lives.
Although Isabella cannot be called a villain, she causes many problems over the course of the novel. Isabella manages to weasel a marriage proposal out of James, but when she discovers that he is not as rich as she assumed, she begins flirting with Frederick Tilney. Isabella can be seen as a gold-digger interested only in money, as an attractive girl who cannot refuse the attention of a young man, particularly a wealthy or well-known one, or as someone who simply can't figure out what she wants. But most modern interpretations of Isabella analyze her as one of Austen's ironic caricatures, an exaggeration of the emphasis on wealth and position that often preoccupied high society.