In 1764, Thomas Gray wrote to thank his friend Horace Walpole for the gift of Walpole’s
new novel, The Castle of Otranto (1764). In his letter, Gray admitted, “[It] engages our attention
here, makes some of us cry a little, and all in general afraid to go to bed o’ nights” (137). As
Gray’s comment makes clear, Walpole’s literary creation has inspired terror in its readers since
its publication. Through its distinctively dark setting, subterranean passages, and supernatural
dangers like the infamous giant helmet, Walpole initiated a new literary genre — the Gothic
novel — in which he brought together “the two kinds of romance, the ancient and the modern,”
or, the romance and the novel, in order to create a literary form that was both realistic and highly
imaginative (Walpole 9).
Despite the terror that the supernatural elements of the novel imbue in the storyline, as
E.J. Clery and other scholars have shown, the supernatural elements in Otranto and its Gothic
descendants are not the primary source of terror. Clery suggests that the human villains in Gothic
novels emerge as more terrifying than any ghosts due to their sinister intentions for the young
heroines of these stories. Otranto opens with the notorious scene of the giant helmet that crushes
Conrad to death, but the fear in the story is not from other giant falling objects but rather the
looming threat Conrad’s father, Manfred, poses to the women around him. Since Manfred
interprets his son’s death as an omen forecasting the ending of his family’s reign, he seeks to
reestablish his bloodline and confirm his authority by forcing Conrad’s betrothed Isabella to
marry him instead. Isabella, however, declines his proposal and flees, resulting in a chaotic and
fearful chase as Manfred pursues her through the castle’s dark underground halls.
While previous scholars attribute the Gothic’s terror solely to the nefarious intentions of
its villains, they fail to recognize the extent to which the dark setting magnifies the terror by
eliminating the heroines’ sight. Darkness envelops Otranto, with Isabella’s escape taking place at
night through the castle’s subterranean passages. For Isabella, darkness itself poses a danger
because, without light, she loses visual sensory perception and the ability to create knowledge of
her surroundings. Walpole’s novel speaks to almost a century of philosophical debates about the
connection between the imagination, sensory perception, and the formation of knowledge.
Enlightenment thinkers such as John Locke argued that the ability to think arises through
empirical observation of the world. In his 1689 Essay Concerning Human Understanding, Locke
notes that “external and internal sensation, are the only passages I can find, of Knowledge, to the
Understanding. These alone, as far as I can discover, are the windows by which Light is let into
this dark Room” (123). Locke suggests humans generate knowledge through sensory observation
— including vision — of the world, metaphorically comparing knowledge acquired through
sensation to “Light” illuminating the otherwise “dark” mind. Rather than use darkness as a
passive aesthetic feature of his ancient Gothic setting, Walpole weaves darkness into Otranto to
manipulate Isabella’s visual sensory perception and, accordingly, her ability to knowledgeably
think. Darkness, therefore, invokes terror in Isabella not only by concealing danger but also by
preventing her from taking in visual data that she can use to generate knowledge and devise her
plan to escape, instilling fear of not only the unknown but also the unseeable.
Manfred reveals to Isabella that darkness does not impede his physical movements,
contributing to her fear of his pursuit through the underground passages. After Manfred demands
a servant bring Isabella to him, he orders the servant, “Take away that light, and begone. Then
shutting the door impetuously, he flung himself upon a bench against the wall, and bade Isabella
sit by him” (Walpole 23). Through Manfred’s removal of a light source from the room, Walpole
emphasizes Manfred’s propensity to enact evil in darkness. Manfred demonstrates an embodied
power in the darkness through his impetuous behavior, confidently flinging himself upon the