The primary theme of this book is coming of age. In this process Mattie realizes a number of other themes, such as the fact that the world isn't what it seems, or the central importance of duty. All settings and symbols should be interpreted in light of these core themes. For example, all the yearning to go away to college is a mark of people on the verge of a major transformation. As far as symbols, the book Mr. Eckler tells Mattie about is one example of such a symbol. Wharton's "The House of Mirth" draws its title from a bible verse, and in buying it Mattie may be a fool. It also shows people caught between social rules and personal desires, like the real people in this book.