LitCharts assigns a color and icon to each theme in Heart of Darkness, which you can use to track the themes throughout the work.
Colonialism
The Hollowness of Civilization
The Lack of Truth
Work
Racism
Summary
Analysis
Marlow stares at the Russian in astonishment, and thinks that the Russian "surely wants nothing from the wilderness but space to breathe in" and that "if the absolutely pure, uncalculating, unpractical spirit of adventure had ever ruled a human being, it ruled this ... youth."
Here's the Russian's secret. He's the only white man in colonial Africa not looking for money or power. Without the will to dominate, he seems safe from corruption.
Meanwhile, the Russian begs Marlow to take Kurtz away quickly. He tells of his first meeting with Kurtz, in which Kurtz "talked of everything" and the Russian only listened. Since then, he says he's nursed Kurtz through two illnesses, even though Kurtz had once threatened to shoot him over some ivory.
Kurtz talked of "everything." Of course, talking of everything is a lot like talking of "nothing." Note that the color white, the color of blindness in Heart of Darkness, is the result of every color brought together into one.
Kurtz, the Russian says, is a god to the local tribesman, who adore him. They help him as he raids the jungle and other tribes for ivory. This comes as troubling news to Marlow, who had expected that Kurtz, with his morals, would trade for ivory, not take it by force.
Here is Marlow's first solid evidence that Kurtz has abandoned his morals. (When Marlow earlier told the men on the Nellie that Kurtz became a monster, he was flashing forward in his narrative.)
The Russian says that Kurtz can't be judged as other men are. He adds that Kurtz "suffered too much. He hated all this and somehow couldn't get away." Marlow, meanwhile, lifts binoculars to his eyes and looks at the building where he thinks Kurtz is lying ill. He's startled to see that what he thought were fence posts are actually spiked human heads. Marlow tells the men on the Nellie that for all Kurtz's magnificent talent, eloquence, and learning, he was hollow at the core, and the jungle filled that hollowness.
When he described the Roman conquerors in England at the beginning of Heart of Darkness, Marlow imagined them as appalled and attracted by its savagery. The same is true for Kurtz, who both "hated all this" and spiked heads to stakes. His hollow civilized core, for all its outward beauty, couldn't hold out against the jungle's "inner truth."
The Russian mentions that when the native chiefs came to see Kurtz they crawled up to him. This information disgusts Marlow, who comments that in contrast "uncomplicated savagery was a positive relief, being something that had the right to exist—obviously—in the sunshine."
Here's another instance of Marlow's condescending preference for the simplicity of the "savage" natives to the corrupt and complicated civilized men.
The pilgrims come out of the house bearing Kurtz on a stretcher. Marlow describes Kurtz as looking like "an animated image of death carved out of ivory." The natives swarm forward. The Russian whispers to Marlow that if Kurtz says the word, they'll all be killed. Kurtz speaks (Marlow can't hear him from so far away), and the natives melt back into the jungle.
Kurtz, the epitome of civilized man, has transformed himself into a god to the natives. He even looks like a god: "an image of death carved out of ivory." The lure of power and domination was too great for him too resist.
Along the shore of the river near the ship the natives gather. Among them, next to the ship a "savage and superb" African woman paces back and forth. The Russian's comments about her imply that she was Kurtz's mistress.
Kurtz was so transformed by the jungle he even betrayed his Intended.
Inside the cabin, an argument erupts between Kurtz and the General Manager. Kurtz accuses the General Manager of caring less about Kurtz himself than about the ivory Kurtz has, and also says the General Manager with his "piddling notions" is interfering with Kurtz's grand plans.
Somehow Kurtz still sees himself as a man of great ideas, just as civilized Europeans continue to see colonialism as noble while it abuses the Africans and steals their wealth.
The General Manager exits from the cabin. He tells Marlow that Kurtz is very ill and that Kurtz's "unsound methods" ruined the district for the company. Marlow comments that Kurtz's methods couldn't be "unsound" because he seemed to have had "no method at all." Yet Marlow is more disgusted by the General Manager's fake show of sadness at Kurtz's demise than with Kurtz's atrocities, and says that Kurtz is still a remarkable man. This loses Marlow whatever favor he'd held in the General Manager's eyes.
Marlow has a choice to make between the General Manager's "pretending" devil of false civility, and Kurtz's "lusty" devil of monstrous domination. He chooses Kurtz, perhaps for the same reason he prefers donkeys and savages to Europeans. In Kurtz, though there was monstrousness, there was no lie. The jungle filled Kurtz's hollowness, but not the General Manager's.
When Marlow is alone, the Russian approaches. He has decided to slip away, correctly sensing that he's in danger from the General Manager and his men, and seeing nothing more that he can do for Kurtz. But before departing he tells Marlow that it was Kurtz who ordered the native attack on the steamship in order to scare the General Manager away and thereby be allowed to remain at his station. The Russian gets Marlow to give him some supplies and disappears into the night.
The Russian disappears into the jungle, going off alone as no other European colonist would. That European, though, would be thinking of himself as in conflict with the jungle because, as a colonist, his goal is to dominate and subdue the jungle. But the Russian has no such dreams, and so is safe and unafraid.
Marlow goes to sleep, but wakes suddenly just after midnight. As he looks around he notices Kurtz has disappeared. On the bank of the river, Marlow finds a trail through the grass and realizes Kurtz must be crawling. He catches up to Kurtz just before he reaches the native camp. Marlow realizes that though he's stronger than Kurtz, all Kurtz has to do is call out and the natives will attack. Kurtz, realizing the same thing, tells him to hide. Marlow says, "You will be lost, utterly lost." Kurtz pauses, struggling with himself. Marlow watches him, and realizes that Kurtz is perfectly sane in his mind, but his soul is mad. Kurtz's soul, Marlow says, "knew no restraint, no faith, and no fear." Yet in the end Kurtz allows Marlow to support him back to the ship.
This is the climax of Heart of Darkness. With the words "You will be lost," Marlow forces Kurtz to battle in his own soul, to choose between his savage monstrousness and his civilized dreams of advancement and accomplishment. Kurtz ultimately chooses civilization. He chooses the impractical and idealism of his treatise "On the Suppression of Savage Customs" over his later brutish scrawl, "Exterminate all the brutes."
The next day the ship departs. Kurtz, in the pilothouse with Marlow, watches the natives and his mistress come to the shore. Marlow spots the pilgrims getting their rifles and pulls the steam whistle. All the natives but the woman disperse. The pilgrims open fire, blocking Marlow's vision with the smoke.
The pilgrim's pointless gunfire, a product of their colonialist greed and the savage desire to hurt and dominate, puts out a smoke as blinding as the white fog. Civilization continues to blind itself.
As they travel swiftly downstream, the General Manager is pleased. After all, soon Kurtz will be dead and the General Manager will be secure in his position without having to do a thing. Marlow is often left alone with Kurtz, who speaks in his magnificent voice and with his magnificent eloquence about his moral ideas, his hopes for fame in Europe, and his desire to "wring the heart" of the jungle.
Another example of false civility: the General Manager doesn't care that Kurtz is going to die as long as he can't be blamed for it. Kurtz, meanwhile, wavers between monstrous savagery and belief in the ideals of civilization that his actions have proved hollow.
The steamship soon breaks down, which doesn't surprise Marlow. But Kurtz becomes concerned he won't live to see Europe. He gives Marlow his papers, fearful that the General Manager might try to pry into them, and one day tells Marlow that he is "waiting for death." Marlow is pierced by the expression on Kurtz's face "of somber pride, of ruthless power, of craven terror—of an intense and hopeless despair." Suddenly Kurtz cries out in a voice not much more than a breath: "The horror! The horror!" A short while later, the General Manager's servant appears and informs everyone: "Mistah Kurtz—he dead."
In Kurtz, an enlightened European surrounded by the brutal primitivism of the natives and the greed of the Company agents, Marlow saw the possibility of an answer to his own despair about the darkness of men's hearts on one side and the hollowness of civilization on the other. And Kurtz does provide an answer, of sorts: there is no answer, only despair, only horror.
Soon after, Marlow himself falls ill. He calls his struggle with death "the most unexciting contest you can imagine," and is embarrassed to discover that on his deathbed he could think of nothing to say. That's why he admires Kurtz. The man had something to say: "The horror!" Marlow's describes Kurtz's statement as a moral victory paid for by "abominable terrors" and "abominable satisfactions."
Marlow's esteem for Kurtz's statement is part of his general respect for work. Through the corruption of his ideals, Kurtz saw the world as it was. And like the helmsman who "had done something, he had steered," Kurtz did something, he judged: the horror!
Marlow returns to the "sepulchral city" in Europe, where his aunt nurses him back to health but can't soothe his mind. The people of the city seem to him petty and silly.
The people in the city, who have never seen the jungle, can't see the hollowness of their civilization. They can't see the horror.
A representative of the Company comes to get Kurtz's papers from Marlow, who offers him only On the Suppression of Savage Customs (with the scrawled "exterminate all the brutes torn off" torn off). The representative wanting more, wanting something more profitable, storms off.
The same greed visible in the Company agents is visible in the Company representative. Note how Marlow protects Kurtz's reputation.
Kurtz's cousin soon shows up. The cousin, a musician, tells Marlow that Kurtz was himself a great musician, then leaves with some family letters Marlow gives him.
Kurtz seems to have just reflected people back at themselves. Another indication that he was more surface than self.
Soon after, a journalist stops by. He says Kurtz wasn't a great writer, but was a great speaker. He could have been a great radical political leader—he could electrify a crowd. Marlow asks what party Kurtz would have belonged to. The journalist says any party: Kurtz could convince himself of anything. He takes On the Suppression of Savage Customs for publication.
The journalist's assertion that Kurtz could convince himself of anything further supports the idea of Kurtz's hollowness. He didn't care what his ideals were, as long as he was passionate about them.
At last, Marlow works up the nerve to go to see Kurtz's Intended and give her the last of his letters. When she lets Marlow into her house he notices that though it's a year after Kurtz's death, she is still dressed in mourning black. She praises Kurtz as the best of all men.
Marlow's aunt established women in H of D as symbols of society's blindness to its own hollowness. Kurtz's Intended further supports this symbolism: she is completely clueless about Kurtz's true nature.
Marlow, full of pity, does not dispute her claims. Finally, the Intended asks to hear Kurtz's last words. This is the question Marlow's been dreading. He pauses, then tells her that Kurtz's last words were her name. She cries out that she knew it and begins to weep. Marlow feels only despair, knowing he failed to give Kurtz the justice he deserved. But he just couldn't get himself to tell the Intended the truth—it would have been too dark.
Though Marlow knows Kurtz's triumph lay in his understanding of men's pretty delusions about themselves, he can't bring himself to make Kurtz's Intended see the dark reality. And Marlow knows that if he, who sees civilization's hollowness, can't bring himself to reveal the darkness beneath, then civilization's blindness is complete.
Marlow, on the Nellie still at anchor in the Thames, goes quiet. The Narrator looks off into the distance, and says that the Thames seems to lead to the "uttermost ends of the earth," seems to lead "into the heart of an immense darkness."
Marlow's story, though, forces the Narrator to see civilization's dark heart. The Narrator's connection of that darkness to the Thames indicates he now realizes his former romantic ideas of colonialism were symptoms of civilization's self-delusion.