Kurtz is driven to madness by the imperialistic attitudes of those around him, and his own greed for money via the ivory trade. He spends his life in the jungle, searching for ivory and coming to know the natives, who think he is a white God. He represents the very worst of imperialism, because he comes to know and understand the natives, and still he takes advantage of them. He loves their hero worship, and he trades for ivory with them, but he is still using them and leaving them with little or nothing in return, just as the Belgians leave the Congo when they have taken all they can get from the country and the people. The novel also illustrates how jaded the Europeans are, and how they take the natives for granted, seeing them as little more than animals or "things" to serve them. This is illustrated when Marlow views the "black shadows" who are slowing wasting away from the harsh work and treatment of the Europeans, but also in the overall indifference they have to the natives around them and the culture they are losing. Critic Parry continues, "Moreover, at a time when lies about a benevolent empire circulated widely within the imperial homeland, Heart of Darkness casts a cold eye on imperialism as a world system managed from the metropolitan centers in the interest of these centers" (Parry 42). Imperialism was an evil practice, and Conrad recognized this even at a time when many Europeans did not. Bringing it to the forefront was his purpose in writing this novel, and the theme is woven throughout the pages with clarity and intention. The...

The theme is dark, the setting is dark, and the outcome is dark. Conrad is saying that nothing good can come from imperialism, and he uses Kurtz' death and the "horror" surrounding it to drive the point home. The fact that he lies to Kurtz' fiance is the final blow; it represents the lies the Europeans have been swallowing about imperialism and what it entailed for years.
In conclusion, "The Heart of Darkness" is a disturbing novel that illustrates the evil of European imperialism and conquest. The Congo will never be the same after the Belgians are through with it, and neither will the people. Kurtz dies groaning "the horror!" And that is the real theme of this novel - the horror of imperialism and what it does to a country and its culture. Conrad peppers the novel with references to this horror, and by the time the novel is through, the reader understands just what a horrible practice imperialism was, and how it change the face of entire continents, seemingly overnight, all in the name of greed, avarice, and political power.