Themes are the fundamental and often universal ideas explored in a literary work.
The Hypocrisy of Imperialism - Heart of Darkness explores the issues surrounding imperialism in complicated ways. As Marlow travels from the Outer Station to the Central Station and finally up the river to the Inner Station, he encounters scenes of torture, cruelty, and near-slavery. At the very least, the incidental scenery of the book offers a harsh picture of colonial enterprise. The impetus behind Marlow's adventures, too, has to do with the hypocrisy inherent in the rhetoric used to justify imperialism. The men who work for the Company describe what they do as "trade," and their treatment of native Africans is part of a benevolent project of "civilization." Kurtz, on the other hand, is open about the fact that he does not trade but rather takes ivory by force, and he describes his own treatment of the natives with the words "suppression" and "extermination": he does not hide the fact that he rules through violence and intimidation. His perverse honesty leads to his downfall, as his success threatens to expose the evil practices behind European activity in Africa. However, for Marlow as much as for Kurtz or for the Company, Africans in this book are mostly objects: Marlow refers to his helmsman as a piece of machinery, and Kurtz's African mistress is at best a piece of statuary. It can be argued that Heart of Darkness participates in an oppression of nonwhites that is much more sinister and much harder to remedy than the open abuses of Kurtz or the Company's men. Africans become for Marlow a mere backdrop, a human screen against which he can play out his philosophical and existential struggles. Their existence and their exoticism enable his self-contemplation. This kind of dehumanization is harder to identify than colonial violence or open racism. While Heart of Darkness offers a powerful condemnation of the hypocritical operations of imperialism, it also presents a set of issues surrounding race that is ultimately more troubling.
Madness as a Result of Imperialism - Madness is closely linked to imperialism in this book. Africa is responsible for mental disintegration as well as for physical illness. Madness has two primary functions. First, it serves as an ironic device to engage the reader's sympathies. Kurtz, Marlow is told from the beginning, is mad. However, as Marlow, and the reader, begin to form a more complete picture of Kurtz, it becomes apparent that his madness is only relative, that in the context of the Company insanity is difficult to define. Thus, both Marlow and the reader begin to sympathize with Kurtz and view the Company with suspicion. Madness also functions to establish the necessity of social fictions. Although social mores and explanatory justifications are shown throughout Heart of Darkness to be utterly false and even leading to evil, they are nevertheless necessary for both group harmony and individual security. Madness, in Heart of Darkness, is the result of being removed from one's social context and allowed to be the sole arbiter of one's own actions. Madness is thus linked not only to absolute power and a kind of moral genius but to man's fundamental fallibility: Kurtz has no authority to whom he answers but himself, and this is more than any one man can bear.
The Absurdity of Evil - This novella is, above all, an exploration of hypocrisy, ambiguity, and moral confusion. It explodes the idea of the proverbial choice between the lesser of two evils. As the idealistic Marlow is forced to align himself with either the hypocritical and malicious colonial bureaucracy or the openly malevolent, rule-defying Kurtz, it becomes increasingly clear that to try to judge either alternative is an act of folly: how can moral standards or social values be relevant in judging evil? Is there such thing as insanity in a world that has already gone insane? The number of ridiculous situations Marlow witnesses act as reflections of the larger issue: at one station, for instance, he sees a man trying to carry water in a bucket with a large hole in it. At the Outer Station, he watches native laborers blast away at a hillside with no particular goal in mind. The absurd involves both insignificant silliness and life-or-death issues, often simultaneously. That the serious and the mundane are treated similarly suggests a profound moral confusion and a tremendous hypocrisy: it is terrifying that Kurtz's homicidal megalomania and a leaky bucket provoke essentially the same reaction from Marlow.
Motifs are recurring structures, contrasts, or literary devices that can help to develop and inform the text's major themes.
Observation and Eavesdropping - Marlow gains a great deal of information by watching the world around him and by overhearing others' conversations, as when he listens from the deck of the wrecked steamer to the manager of the Central Station and his uncle discussing Kurtz and the Russian trader. This phenomenon speaks to the impossibility of direct communication between individuals: information must come as the result of chance observation and astute interpretation. Words themselves fail to capture meaning adequately, and thus they must be taken in the context of their utterance. Another good example of this is Marlow's conversation with the brickmaker, during which Marlow is able to figure out a good deal more than simply what the man has to say.
Interiors and Exteriors - Comparisons between interiors and exteriors pervade Heart of Darkness. As the narrator states at the beginning of the text, Marlow is more interested in surfaces, in the surrounding aura of a thing rather than in any hidden nugget of meaning deep within the thing itself. This inverts the usual hierarchy of meaning: normally one seeks the deep message or hidden truth. The priority placed on observation demonstrates that penetrating to the interior of an idea or a person is impossible in this world. Thus, Marlow is confronted with a series of exteriors and surfaces—the river's banks, the forest walls around the station, Kurtz's broad forehead—that he must interpret. These exteriors are all the material he is given, and they provide him with perhaps a more profound source of knowledge than any falsely constructed interior "kernel."
Darkness - Darkness is important enough conceptually to be part of the book's title. However, it is difficult to discern exactly what it might mean, given that absolutely everything in the book is cloaked in darkness. Africa, England, and Brussels are all described as gloomy and somehow dark, even if the sun is shining brightly. Darkness thus seems to operate metaphorically and existentially rather than specifically. Darkness is the inability to see: this may sound simple, but as a description of the human condition it has profound implications. Failing to see another human being means failing to understand that individual and failing to establish any sort of sympathetic communion with him or her.
Symbols are objects, characters, figures, or colors used to represent abstract ideas or concepts.
Fog - Fog is a sort of corollary to darkness. Fog not only obscures but distorts: it gives one just enough information to begin making decisions but no way to judge the accuracy of that information, which often ends up being wrong. Marlow's steamer is caught in the fog, meaning that he has no idea where he's going and no idea whether peril or open water lies ahead.
The "Whited Sepulchre" - The "whited sepulchre" is Brussels, where the Company's headquarters are located. A sepulchre implies death and confinement, and indeed Europe is the origin of the colonial enterprises that bring death to white men and to their colonial subjects; it is also governed by a set of reified social principles that both enable cruelty, dehumanization, and evil and prohibit change. The phrase "whited sepulchre" comes from the biblical Book of Matthew. In the passage, Matthew describes "whited sepulchres" as something beautiful on the outside but containing horrors within (the bodies of the dead); thus, the image is appropriate for Brussels, given the hypocritical Belgian rhetoric about imperialism's civilizing mission. (Belgian colonies, particularly the Congo, were notorious for the violence perpetuated against the natives.)
Women - Both Kurtz's Intended and his African mistress function as blank slates upon which the values and the wealth of their respective societies can be displayed. Marlow frequently claims that women are the keepers of naive illusions; although this sounds condemnatory, such a role is in fact crucial, as these naive illusions are at the root of the social fictions that justify economic enterprise and colonial expansion. In return, the women are the beneficiaries of much of the resulting wealth, and they become objects upon which men can display their own success and status.
The River - The Congo River is the key to Africa for Europeans. It allows them access to the center of the continent without having to physically cross it; in other words, it allows the white man to remain always separate or outside. Africa is thus reduced to a series of two-dimensional scenes that flash by Marlow's steamer as he travels upriver. The river also seems to want to expel Europeans from Africa altogether: its current makes travel upriver slow and difficult, but the flow of water makes travel downriver, back toward "civilization," rapid and seemingly inevitable. Marlow's struggles with the river as he travels upstream toward Kurtz reflect his struggles to understand the situation in which he has found himself. The ease with which he journeys back downstream, on the other hand, mirrors his acquiescence to Kurtz and his "choice of nightmares."