A key theme in The Garden of Eden is the way in which characters challenge or adhere to social conventions. The primary example of this is Catherine, who craves a sense of identity or uniqueness and believes that defying social expectations will grant it to her. Catherine is a rich young woman who has recently lost both her parents; she has no job, interests, or hobbies beyond living well and being married to David. She had nothing substantive by which to define herself until David appeared in her life. She does not want to be just a wife, however, as she perceives the limitations this role places upon her. She seeks to create a new identity by challenging such conventions. This constant desire to challenge preconceived ideas becomes her identity, and defiance of expectation becomes her only real character trait.

Catherine’s unconventional behavior accelerates throughout the novel. At first, she wears trousers and cuts her hair short, adopting masculine aesthetics which force people to pay attention to her. People stop in the street and stare at her short, boy-like haircut while the local priest and other members of the community disapprove of her predilection for traditionally male garments.