One major theme of The Madwoman in the Attic is feminism. In this work, modern literary critics Sandra Gilbert and Susan Gubar apply contemporary feminist perspectives to nineteenth-century literature. In doing so, they show how male and female authors differently rendered the gendered character of society and gender relations. Their study indicates a glaring difference between male-authored and female-authored visions of literary women and notes feminist roots in several early cases of female-authored works. In such feminist-coded works, Gilbert and Gubar notice the presence of patriarchy as a driving narrative force. They point to its presence as the dominant social system, both in the writing and lives of female authors, highlighting the extreme difficulty—and sometimes impossibility—for female authors to overcome male dominance in their careers and personal lives.

Not only does this personal experience bleed into their work but this patriarchal domination is reprised in the themes, plots, and characters of their fiction. Female-authored works were more often than not confined to a masculine system of prescriptive value, meaning that their work was only respected if it did not stray from the set scenes and themes of respectable literature. As such, early feminist works write from a patriarchal lens that undercuts expected avenues of male-coded writing with the perspective and passion of its female authors. However interesting their work may be, Gilbert and Gubar's study of nineteenth-century feminism is incomplete, as the authors primarily address British fiction, loosely consider American authors and poets, such as Emily Dickenson, and fail to consider the works and experiences of any other female writers of the time

The most specific “madwoman” that Gilbert and Gubar analyze is Bertha Rochester, who, in Charlotte Brontë’s Jane Eyre, is confined to the “attic” of her husband's home. According to her husband, Edward, his wild, out-of-control wife must be hidden away from society, for she is a burden to him, more a curse than a wife, and he seeks to erase her existence. Bertha's character is shaped in sharp contrast to Jane's, who seems submissive, obedient, and as different from Bertha as possible. Yet, despite the vast differences between the two wives of Edward Rochester, the characters, once juxtaposed foils, soon fuse into one. Indeed, Bertha acts as an alter ego for Jane's careful acquiescence to expectation and lack of agency. Upon Bertha's death, Jane becomes a more fully realized person who is decisive and sexually active. By allowing both women's narrative presence, Brontë indicates the difficulty non-conforming women faced.

Gilbert and Gubar carry this subtle nod to the misrepresentation of women throughout their study, extending the intertwined plight of Bertha and Jane to many of the other works they analyze. Using the "madwoman" theme to refer to the personality and behavioral traits that nineteenth-century authors—primarily men—applied to non-conforming women, the pair draw a connection between literary conformity and real-life power struggles. Ideas such as innate insanity and later, hysteria, fit into this trope and were tools often used to control women. Nineteenth-century female writing depicts this predicament, caught up in the desire to be authentic but trapped by the necessity to conform. Their nineteenth-century context limited their agency and obscured their voices. As such, their work disguises the desire to defy convention in the comfortable form of the "madwoman."

The “attic” is both a literal space, as in Bertha’s area of confinement, and a concept. The attic can be the confinement of false identity, similar to the concept of the “closet” regarding sexual identity. For female authors, Gilbert and Gubar explain, the social construction of rationality as inherently male worked against female authors and limited their ability to be taken seriously as intellectuals. The domination of the publishing industry also worked to keep the work of female authors from being signed. Here not only Charlotte Brontë but also her sisters figure into their analysis, as they were initially published under male pseudonyms. Women also had to resist male-imposed stereotypes about audience appeal, often disguising content about female sexual desire through metaphors and analogies.