Let's just say up front that this is a great book and it ought to be widely read. But if it is presented at, say a high school level, it needs a competent instructor. For example, the great novelist Chinua Achebe waged a serious objection to Conrad's admission into the literary canon on the grounds that he was a racist. (Achebe, Chinua. "An Image of Africa: Racism in Conrad's 'Heart of Darkness'" Massachusetts Review. 18. 1977.) Achebe's position was based on his reading of The Heart of Darkness. This, though, is a misreading, and it requires some thought and perhaps, some outside help to see why.
First off, you have to see that the book really has nothing to do with and nothing to say about Africa or its people. There is no dialogue between the races. There is only the notion of difference at some level. As Achebe says in the first paragraphs of his essay on the book, the inhabitants of Yonkers (New York) have their own odd customs and superstitions. And these would be passing strange to a Congolese. But these differences are not the subject Conrad deals with.
Of course there are differences among people: differences in speech, outlook, history and how we go about our daily lives. There really is no value judgment on Conrad's part in this observation. As we've all heard many times, "it's a black thing, you wouldn't understand." Well, like it or not, the statement has some truth to it. That truth is not in our ability or inability to comprehend the beauty of difference in our diverse heritages. Who among us could truly gauge the horror of the holocaust or, as a member of "white" society, give voice to the colonial subjugation of Africa by Europe? Conrad, wisely, does not try to do this.
He does, though acknowledge our common seed of humanity. The point though, is that Conrad finds this seed ugly. It's ugly in both black and white. And what Conrad does in his descriptions of his African experience is to point out that if we peel back our layers of culture, work toward some "primordial ooze," we're all similar at some level. If we strip away the top layers of diversity, there is common clay.
I don't mean to imply that Conrad is claiming Africa is in some permanent state of primal being. Quite the contrary - he did not rule out the possibility of a rich framework of society in Congo. It's just that it is foreign to the colonial mind and, therefore, invisible. I think a fair fraction of Achebe's outrage over the book was that he felt African culture was slighted. But Conrad isn't dismissing the possible beauty of racial diversity. It's just that his subjects are blind to it. All that these "hollow men" of Europe can do is see the primitive similarities, our common point of intersection. That's what Conrad means when he portrays the white vision of foreign culture.
Conversely, many read Kurtz, the central figure of the narrative, as a man "gone native." He was a person who realized the rationality of local belief and custom and "ran with it." In doing this, he saw the ultimate truth, that European culture held no special place in the scheme of the world. This realization was the horror that ultimately destroyed him. This too is a misreading. The text provides us no evidence that Kurtz had any serious thoughts about the native culture or its people - except to exploit them.
Achebe, in his essay, reached beyond the text to make his point. He cites Conrad's youthful diaries to show he had a fawning, near homosexual view of the British body type. But again, if we look into other Conrad works, we find Lord Jim. Jim, too, possessed this ideal British exterior. And yet, under that shell we find an incompetent, flawed, pitiable creature.
Again, the alien presence is just a backdrop. Apart from dominance and subjugation, there is no real dialogue, no meaningful interchange between the races. Conrad is mute on the subject of black history, culture or lifestyle. What Conrad does focus on is what he knows best - late nineteenth century European culture. He is the most severe critic of that culture. As he says, you could poke a hole in those people with your finger and all you'd see inside was a little dirt.
And yes, Conrad does use terms that today, to us, are "politically incorrect." He uses the "n" word with abandon. But you must remember, that our notions of political correctness weren't around over a hundred years ago. And yes, he does portray one African - the steam engineer on Marlow's boat as ridiculous. And the way he describes the engineer is insensitive based on our "modern" viewpoint. But that awful caricature was to demonstrate that if we force a representative of one culture into the mold of another, the result is ludicrous.
There are many "conversations" between whites embedded in Marlow, the narrator's monologue. And in all those conversations, the whites reveal some grasping, petty, self-aggrandizing view of themselves. This is true even of Kurtz, himself. There is the implication in the last paragraphs of the book that his real motive for being in Africa was to earn enough money to seem worthy to his `intended's" family. And, he would come out as a god or a saint at the end to boot!
And what can be said of Kurtz, the enigmatic presence running through the text? He went to Africa ostensibly to "suppress the savage customs," to be a "light of civilization" to the region. He even wrote a pamphlet on the subject. He was certainly a charismatic figure who could rally people around him through personal magnetism and competence. He went through his life in Africa denying, even to himself his true, greed motivated plan.
It is true that in Africa, he came to see his own society and its place in the world in its true shoddy state. This probably came after his failure to amass his redeeming fortune because of his company's "injustice." But moreover, he was so crippled as a person that he could see no good in others. All he could see looking into the human heart was "the horror, the horror" no matter if that heart was black or white. The book portrays the ultimate failure of colonialism and the failure of a human being. The fact that it didn't attempt to provide any insight into the African mind does not make the book a racist screed. Maybe Conrad, personally, was a racist, an anti-Semite as well. His books don't reflect that position.