Discuss the identity crisis in the novel.
The first problem with discussing the notion of an "identity crisis" in the novel is that the term is one from twentieth century popular psychology, and thus cannot be analysed as something "in" novels not directly influenced by that conceptual framework but rather as either something we read into novels or as cognate to fictional traditions from other periods.
The most important pre-20th century concept that describes issues that contributed to the 20th century concept of identity crisis is the Bildungsroman, the coming-of-age novel, that general has a adolescent or young adult protagonist engaging in a journey of self-discovery while finding his or her place in the world. Typical examples are Goethe's Sorrows of Young Werther and Joyce's Portrait of the Artist as a Young Man.
An example of 20th century "identity crisis" would be Catcher in the Rye.