The tone of Flatland changes significantly as the narrative progresses, as Abbot reflects the work's shifting focus and reveals more about A Square’s fate. Initially, the novel’s tone is dry, wry and academic, satirically pointing a critique at the rigidity and absurdity of Victorian society. Narrated in the first person by A Square, the early parts of the book use humor and irony to expose the follies and contradictions of Flatland life. Everything A Square describes seems arbitrary and almost silly, which then makes the reader realize how their own social mores might also seem that way. It's both entertaining and thought-provoking. A Square's perspective as a member of Flatland society provides an insider's view of its flaws. Even though his initial descriptions are more objective than his later ones, there’s still a consistent attitude of criticism in the narrative’s voice.
As the story progresses, the tone shifts to become more educational. The focus turns towards the intricacies of geometry and the concept of dimensions, both in a literal and metaphorical sense. Here, A Square’s voice takes on the role of a teacher, guiding the reader through the underlying principles that govern life in Flatland. Further into the narrative, and especially when A Square begins to narrate his adventures with The Sphere, the tone becomes increasingly philosophical. A Square begins to reflect more deeply on the limitations of his world and his understanding, often expressing frustration and a sense of confinement. As A Square's understanding of the many dimensions he encounters expands, his voice grows more questioning and critical.
The novel ends with a tone of despair and dissatisfaction, as A Square finds himself imprisoned for his "heretical" ideas. This ending reflects the novel's general attitude towards progress and enlightenment that people with new ideas are more often met with resistance and persecution than with a warm welcome. The melancholic tone in the final chapters speaks to the tragedy of A Square's situation. He’s a character who has transcended the limitations of his society's understanding, and who only wants to help people, but he’s brutally punished for it. This shift in tone reinforces the novel's commentary on the challenges of advocating for change and the strength of preexisting social and moral prejudices in the 19th century.