One of the main themes of Matched is the idea that the desire for free will is both powerful and inevitable. It is through Cassia that the idea manifests most effectively. The more the Society tries to control her, the deeper her drive for freedom becomes. By offering Cassia two possible Matches, the Society exposes her to the possibility of choice. As she begins to fall in love with Ky rather than her best friend and official Match Xander, she increasingly awakens to her oppression—and gradually rejects it. She comes to a point where she wants to be able to choose everything for herself. Cassia describes her newly awakened self as a “river of want” (300).

Cassia begins the novel in a state of blissful ignorance. She is content with her life as the Society has laid it out for her. She credits the Society’s Matching System for allowing the population to “live longer and better than any other citizens in the history of the world” (19). Cassia also deems the Society’s policy of euthanasia for those who turn 80 to be fair and humane. She laughs at scenes from a “showing” of people dying in a Society-waged war because she believes they are fake, “overdone,” and “ludicrous” (90).