LitCharts assigns a color and icon to each theme in Flatland, which you can use to track the themes throughout the work.
Social Hierarchy and Oppression
Religion, Divinity, and the Unknown
Reason vs. Emotion
Knowledge and Truth vs. Dogma
Analogy as Satire
Summary
Analysis
A Square continues to illustrate his world by describing its physical environment. Flatland is organized by four cardinal directions (North, South, East, and West), and by a “Law of Nature” there is a constant attraction to the South, which functions as a compass to Flatlanders. A Square explains that this attraction affects the weak, the elderly, and women more than it affects men.
The way in which a physical law of nature (a southern attraction) establishes distinctions of the weak from the strong illustrates how knowledge is manipulated in order to divide society into hierarchies, straying away from truth and becoming dogma.
Active
Themes
Flatland houses do not have windows because light shines on Flatland equally day and night. From the topic of light, A Square makes a digression and begins rambling about how learned men who questioned the origin of light were heavily taxed and put into asylums.
In this book, light symbolizes knowledge and its regulatable boundaries. While it seems that everything is unquestionable in Flatland (light shines equally), the upper classes brutally punish those who seek after higher truths and the unknown.
Active
Themes
Houses in Flatland, diagrammed by the author, are legally required to be pentagonal to ensure public safety, because the angles of square and triangular houses pose a safety hazard to careless people. These houses have separate entrances for men and women.
Notice the juxtaposition between how the state seems to prioritize the well being of its people (the law regarding pentagonal houses) and how it exploits this same “humane” law to discriminate between sexes.