Issues of race and imperialism dominate Conrad's Heart of Darkness. The work as a whole has been interpreted by successive generations of scholars and literary critics as providing the reader with a powerful critique of imperialism and all that it entails.

Imperialism, which Marlow describes in the story as “rapacious and pitiless folly,” is based on the idea that the white race is superior to all others, and therefore has the right to lord it over them. This idea was almost universally shared by white people in Conrad's day, which makes it all the more remarkable that he should take aim at the appalling treatment meted out to the Congolese people by their inhuman imperial overlords.

Even so, Conrad's approach to race and imperialism is not quite as straightforward as we might think. His portrayal of Africans has been described in some quarters as, at best, one-dimensional, and, at worst, racist. There's certainly no doubt whatsoever that Conrad's representation of Africans would not be considered acceptable in this day and age.

However, some critics have leaped to Conrad's defense by saying that the portrayal of Africans in the novel is exactly what one would expect to see through the eyes of a white colonialist like Marlow. One should never forget that what we see of Africa in the story is from Marlow's somewhat narrow perspective, so it's not surprising if Africans are portrayed as they are.

This in no way makes their portrayal any less offensive, but it does at least enable us to see that Conrad's treatment of the issues of race and colonialism, while being complex in other respects, is much less so in others.

Race and imperialism are integral to the plot of Joseph Conrad's Heart of Darkness. As protagonist Marlow travels further up the Congo River in search of Kurtz, he becomes increasingly aware of the toll that British imperialism has taken upon the local communities. At the "Outer Station," for example, he sees that the company he works for has forced the African people into working in inhumane conditions. Marlow himself comes to embody his country's racist treatment of African people; when an African helmsman dies during an attack on his boat, Marlow pushes his body into the water in a callous display of the racism inherent in Britain's colonization of Africa.

Eventually Marlow meets Kurtz, who serves as the face of imperial evil in Conrad's tale. Kurtz has abandoned all concern for morality—he has been brutally massacring villagers, stealing their ivory, and putting their heads on stakes as a warning. Despite this savage immorality, some still use racist ideology to justify Kurtz's behavior; a Russian trader tells Marlow that a local woman with whom Kurtz had an affair was responsible for his corruption.

Perhaps the most profound statement about racism and imperialism found in the novel is the fact that Kurtz never has to face consequences for his actions. He dies in the jungle, and when Marlow returns to England, he lies to Kurtz's widow about her husband's activities. This prompts the reader to wonder what other monstrous acts have been smudged out of history due to the racist narrative of imperialism.

Racism is the overt justification for the brutal imperialism that European nations exercise in Africa. The racist assumption of the white Europeans is that their European culture and religion is superior to that of the supposedly primitive Black Africans. Nations and private companies whose real goals are to exploit Africans and their resources to the utmost for their own gain manage to convince their populations that humanitarian impulses guide their decisions to take over native peoples.

For example, Kurtz apparently starts out with good intentions toward Africans, sincere in his wish to export civilization to people he deems "savages." When he gets to Africa, however, and realizes that the real name of the game is maximum profit, no matter what, he changes and adopts the openly racist and genocidal attitudes of the European business owners in Africa. Collecting the most possible ivory becomes his obsession, and he is careless of how many Black people he kills to fulfill and surpass his quotas. In fact, his good intentions towards Africans turn into the declaration, "Exterminate all the brutes!" In this, he articulates the underlying reality of European desires. As Marlow says, "all of Europe contributed to the making of Kurtz." This is underscored by Kurtz being half English and half French with a German last name.

In short, racism allows Europe's leaders to mask ruthless imperialism under the softer guise of civilizing and Christianizing the African people.

Both race (or even racism) and imperialism are treated as the common attitudes of white people at the time the book takes place.  This book is set on the river Thames around the turn of the 20th century.  Generally speaking, the Europeans aboard the ship (as well as most other Europeans at this time) are largely ignorant of the lives of the natives they encounter traveling.  Because these natives look so very different, the general attitude is that they are sub-human - closer to animals than they are to humans.  This is evidenced by the repeated referrals of black people as "niggers," "cannibals," "criminals," and "savages."

Kurtz's treatise, called the "International Society for the Suppression of Savage Customs" is yet further evidence of the elitist attitude carried by white men at this time.  It is one thing to merely refer to those peoples in passing as less than human - here is a man (and the characters who support his thinking) who genuinely believes they are harmful to civilized society, so he plans to educate others to fear them.

Marlow is one of the few characters whose thoughts pose an opposition to the general attitude of indifference if not blatant disrespect.  He is often reflecting with sympathy on different situations in which groups of black men are seen working or enslaved.  His thoughts rarely drive him to action and even his actions (like sharing the buscuit with the man on his ship) are as slight as his sympathy - but it is clear the author presents this opposing viewpoint to remind the audience of the humanity of a group of people who are viewed and mostly treated, like animals.

The book is a reflection of the reality that imperialism almost inevitably involves the colonizing of a country of darker-skinned people by a lighter-skinned people. Sometimes there is a racial difference, but not always. The colonizing of India, for example, did not generally involve a racial difference, since Indians have been considered Caucasian by anthropologists and India was occupied by the English and the Portuguese, also Caucasian. But this novella concerns a section of Africa that held black native peoples, and since it is the English colonists and merchants who occupy the area, certainly, there is an issue of race.

Since in the Western world, we tend to use darkness to symbolize evil and lightness to symbolize good, a person might reasonably suppose that the title suggests that Africa is a dark, thus evil, continent, colonized by light, thus good, people, but that is not the case. It is the English who have dark hearts, not the native Africans.

Each "scene" as the narrator travels up the river to the heart of this darkness is carefully selected to show the English in the worst possible light, as a people who treat others inhumanely for their own gains of money and power.

There are those who seem to think that Conrad glorified colonialism and portrayed Africans as savages, but I think a careful reading of the story does not support this.

Kurtz concludes that Europeans must "'Exterminate all the brutes!'"  Marlow suggests that Kurtz's time in the heart of Africa has caused him to exhibit a primitive, instinctual nature, a nature that Marlow suggests is in all civilized societies, just waiting to re-emerge.

Kurtz becomes a god to the natives because he has unabashedly moved from superego (ethics) to id (desire) in his time in the jungle.  They see him as a grand paradox, able to operate in two words and, in the end, choosing their world instead of his own native one.

Look at Marlowe's description:

"All Europe contributed to the making of Kurtz, and by and by I learned that most appropriately the International Society for the Suppression of Savage Customs had entrusted him with the making of a report for its future guidance." (p.49)

Look at what the Harlequin says of Kurtz:

"'You don't talk with that man-you listen to him.'" (p. 53)

"'I tell you,' he cried, 'this man has enlarged my mind.'" (p. 54)

"'You can't judge Mr. Kurtz as you would an ordinary man.'" (p. 56)"But his soul was mad.  Being alone in the wilderness, it had looked within itself and, by heavens I tell you, it had gone mad." (p. 66)