Order
The Society relies on statistical probabilities whenever possible and confines its citizens to strict, organized lives of proper diets, adequate exercise, underwhelming amounts of information, and ideal romantic partners. Every action has a purpose; every schedule is efficient and thought-out. When the maple trees in people’s yards grow naturally rather than uniformly, they are cut down. Even the garbage citizens incinerate is monitored and recorded to ensure that nothing is destroyed that shouldn’t be. This kind of systematic order is the foundation upon which all of civilization, according to the Society’s government, maintains peace.
Limitation
Related to order is the theme of limitation. The Society’s government is able to maintain such unquestioning obedience and structure by regulating the environments of its citizens. They receive exposure to only one hundred pre-approved songs, poems, paintings, stories, etc. They cannot write with their hands, only tap keys on screens. They cannot even type out original thoughts: the letter-writers on their home ports allow only for the rearrangement of words and sentiments that others have already created. Citizens are also only allowed to learn about certain fields in order to keep the total amount of knowledge they have at an underwhelming level. Cooks do not learn about plants, and Arboretum workers do not learn to cook. Limitation is what keeps the Society’s unwavering order in balance.
The Freedom to Choose
The fact that Cassia has been presented with two potential life partners, when the Society expressly intends to provide everybody with only one, makes it possible for her to (in theory) choose a partner for herself. For the first time in her life Cassia has an option that the Society did not contrive; this small seed of thought grows into a jungle of character development for her, turning her from a law-abiding citizen to one filled with doubt about the Society’s ability to make choices for her.
Cassia also observes the difference between herself and Ky: that she at least feels like she has a choice, whereas there is no choice at all for Ky because he is an Aberration. He represents those completely restrained by the inability to choose: where Cassia feels the pull of two different partners, Ky is allowed no partner. Together, Cassia and Ky form a dichotomy of those with the privilege to have a choice and those who never see options in the first place.
When Cassia is forced to sort food laborers into those who will remain in the center and those who will receive a new vocation, she experiences a bastardized version of the freedom to choose. She is made to sentence workers to either one fate or another within the boundaries of what the Society allows, a representation of the illusory freedom of choice that she's never really had -- in the end, the Society is still making all the choices.
The Color Green
Green is a prominent and significant color throughout the work. It is the dress Cassia is wearing when we meet her, the plainclothes her grandfather wears when he dies, the pill that citizens take to stay calm, and the greenspaces that bespeckle the otherwise dreary pallet of colors in Cassia's City. In one interview, Ally Condie said, “I... liked the literal connection to [Cassia's] inner self (her green eyes) and to the world around her (like the greenspaces)… It's those things—growing, connecting, believing in herself—that give her the strength to resist taking the green tablet.” In another interview, she says that the green represents growth and renewal for Cassia, which we see throughout the book as Cassia grows and learns about her government and her place within the Society -- the growth that facilitates her desire to fight back.
Creation
One of the greatest difficulties with which Cassia struggles throughout the book is creating something original, rather than working with what the Society provides her. She is hugely disappointed in herself when her grandfather doesn’t like her letter due to the words are not her own. Her fascination with Ky stems in part from his ability to write and draw, to create things that do not come from anything but his own mind. Ky teaching creativity to Cassia is probably the greatest example of his influence on her, and is the greatest gift he gives to her.
Poetry
Poetry is a driving force behind many of the changes Cassia undergoes throughout the book. “Do not go gentle into that good night” has a profound effect on her, invigorating her with its message that the reader should fight back, which Society citizens do not. She and Ky bond over the secrecy of memorizing and reciting forbidden poetry. From facts that the Society has limited its citizens to only one hundred poems and that, as Cassia observes, none of them incites the kind of upset that her secret one does, one can see that the Society is well aware of the power of poetry: they limit it in order to take advantage of the citizens.
The Color Red
Referenced numerous times in the latter half of Matched is the color red, which Ky and Cassia discuss as representing rebirth and beginning. Ky describes his old home as being more red and orange than the agriculturally blue, green, and brown Oria Province, and denies the idea that the latter set represents growth more than the former. It's no coincidence, given these references to red, that the red tablet is a memory loss drug. The tablet is the Society's appropriation of "new beginnings" as a tool for their own agenda, clearing out any problematic thoughts from their citizens' minds so that they can begin their last 12 hours sans prohibited knowledge.
Flying
Flight represents liberation in Matched. The book opens with Cassia daydreaming of flying on green wings, comparing it to the way in which angels fly. This theme is recalled throughout the book. On top of the Hill with Ky, Cassia says that she feels so high up that she could spread her wings and fly away. At the novel's end, as she plants seeds as part of her work detail, she talks metaphorically of flying with darkness behind, stars ahead, and earth in her hands to remind her of where she came from. The use of flight as an extended metaphor in the novel demonstrates both the freedom of mind that Cassia achieves in Matched, as well as the freedom of choice that she hopes to have in the future.
