Critics and scholars have fit Heart of Darkness into a range of different literary genres, including colonial adventure fiction, psychological mystery fiction, literary modernism, and autobiography. In fact, Conrad consistently blends these genres—and challenges their norms—as part of his critique of European civilization and colonialism.
Broadly speaking, Heart of Darkness is a quest story, in which a hero journeys to a treacherous, unfamiliar place in order to achieve a specific goal. In the book, the sailor Marlow joins the Company and goes on a quest to the inner reaches of the Congo Basin in order to find Kurtz (the man who runs the Company’s Inner Station in the Congo jungle). Yet, like most quest stories, Marlow’s trip really has a deeper, symbolic meaning. Marlow believes that Kurtz is a benevolent visionary who represents the best of Europe, so his quest to find Kurtz is also a metaphorical quest to find moral redemption for European colonialism—and his own personal involvement with it. This is why Conrad focuses heavily on Marlow’s changing feelings and expectations about Kurtz over the course of the book. In this sense, Heart of Darkness could also be seen as psychological fiction, or even a thriller. In fact, because of Marlow’s stream-of-consciousness narration style and consistent focus on his own perceptions, many scholars also view Heart of Darkness as a classic example of literary impressionism.
Heart of Darkness is also like most classic quest stories because Marlow’s journey doesn’t go as planned. Ultimately, Kurtz turns out to be not the best of Europe, but rather a vicious, power-hungry madman who actually represents the evil that lurks behind the façade of civilization. When Marlow learns that Kurtz isn’t who he thought, he realizes that the same thing is true of himself: he isn’t a noble civilizer, but rather an unscrupulous mercenary working to advance a heinous campaign of conquest and murder. In short, Marlow’s quest ends in a grim kind of self-knowledge, and not the redemption he was originally seeking.
It’s worth mentioning that Heart of Darkness isn’t just any old quest story—it’s specifically a colonial travelogue, a genre of story that the book’s early readers would have been very familiar with. From the 15th century onwards, European colonizers began publishing journals, travelogues, and fiction about their overseas conquests. Their books offered most Europeans their only glimpse of their nations’ colonial empires and of life elsewhere in the world. These travelogues deeply shaped Europeans’ perceptions about colonization itself by portraying it as a benevolent, civilizing force. This is why Heart of Darkness was so groundbreaking: it inverted the norms of colonial travel writing. Conrad’s contemporaries were used to reading travelogues that touted the beauty of imperialism, and since Marlow’s story appears to fit the same mold, many would have shared his high hopes for Kurtz. By portraying Kurtz as an utter disappointment, Conrad hoped to shatter the myth of benevolent colonialism and show his readers how other colonial travel writing likely distorted their perceptions.
Like the colonial travelogues that it imitates, Heart of Darkness is also a work of autobiographical fiction—in fact, Conrad based many of the details in the book on his own trip to the Congo eight years before he wrote the book, and critics have long debated whether Kurtz represents a real person Conrad met on his journey. Next, Heart of Darkness is often considered an early example of modernism, the movement of experimental literature that began to challenge social conventions and respond creatively to global change around the beginning of the 20th century. Conrad’s detailed symbolism and critiques of European civilization inspired many later modernist novelists. Finally, the book’s length is significant: it’s a novella, or a work shorter than an ordinary novel but longer than a short story. This format is fitting: it’s short enough to accommodate Conrad’s relatively simple, self-contained plot without losing focus, but it’s long enough to develop the heavy suspense and symbolism on which its conclusion depends.