The Jungle is significant in the heart of darkness because of its symbolic representation of the white man's lack of absolute control. It is personified to be something of an isolationist. “All along the formless coast bordered by dangerous surf, as if Nature herself had tried to ward off intruders” making nature seem unwelcoming of people, especially foreigners, while also alluding to the assumption that it is something uncontrollable, even by the most civilized of men, bringing them to question their totalitarian belief that they could simply parade into a country and rule unopposed as gods. “Could we handle that dumb thing, or would it handle us?” This was one of the only points in the novel in which they may have doubted their ability to rule, showing the ultimate power of the jungle and mother nature, and the fallibility of european conquest.
Kurtz's significance is held in his representation of the inconsistency in both sanity and civilized mannerisms as well as the ever-present greed traditionally seen in colonial culture. He began to drive into insanity once made a virtual god by the natives. This was due to the abundance of greed seen in Kurtz. It was in fact so evident that Marlow describes Kurtz in chapter two using "powers of darkness have claimed him for their own," showing how the immense power bestowed upon Kurtz not only affected him, but changed him. “The wastes of his weary brain were haunted by shadowy images now – images of wealth and fame revolving obsequiously round his unextinguishable gift of noble and lofty expression,” in chapter three is used to represent Kurtz's progression into insanity. This begs the question as to who is in fact more civilized, and does being European automatically ensure sanity? Kurtz turns that answer into a resounding “no,” representing not only Marlow's, but Conrad's critique of European imperialism.
Madness holds significance in its representation of the sub-surface issues held in maintaining the facade of “civilized” colonial culture. "He was very anxious for me to kill somebody, but there wasn't the shadow of a carrier near. I remembered the old doctor—'It would be interesting for science to watch the mental changes of individuals, on the spot.' I felt I was becoming scientifically interesting." is demonstrative of the twisted mannerisms to which the Europeans we succumbing. The moment in which he recognizes his own scientific interest shows the severity of the change occurring in not only his mind, but the mind of other white imperialists, making it apparent that abnormality isn't something that is solely in the confines of “savages.”
Cannibals are significant because they surprisingly show vividly the humanity in which the natives possess. Their usage of restraint in not eating the foreigners demonstrates just how civilized someone so “savage” could be. “Why in the name of all the gnawing devils of hunger they didn’t go for us - they were thirty to five - and have a good tuck in for once, amazes me now when I think of it,” shows this restraint at an incredibly personal level, being that their most readily available source of food were the Europeans. Marlow describes them as an “improved specimen,” begging the question of who really is the most or least civilized. The natives were able to change a vital part of their life and culture to accommodate strangers, but the Europeans were not willing to do the same, that is, halting their mindless conquest of other cultures. The Cannibal's restraint allows the reader to begin see the fallibility of the colonized, greed driven “civilization” that the Europeans have created, and without this interaction, the lack of raw humanity in Europeans, and the present humanity in natives would not be so apparent.
The Congo River is significant in that it is the purest, unadulterated element of nature throughout the book. While Europeans are making an attempt to colonize the ends of the Earth, the river remains untouched, and also, untouchable. It is described in chapter two as “like traveling back to the earliest beginnings of the world, when vegetation rioted on the earth and the big trees were kings. An empty stream, a great silence, an impenetrable forest,” showing the immense power which the river possessed. It is also described as being presumably prehistoric, untouchable, and trapped in time through, “everything you had known once—somewhere—far away—in another existence perhaps.” this was clearly something that the Europeans respected and sought to leave alone which is why it is significant. Amongst the abundance of conquest, one thing remained consistent, that being the river.
The Heart of Darkness at it's core is European imperialism. In their mad dash towards universal conquest, “civilized” Europe often forgets to account for the humanity present in their contemporaries. The Heart of Darkness being Europe and it's imperialistic principles are derived from the passage referring to the return of the white men to Europe and their gazing on the Thames River, “the tranquil waterway leading to the uttermost ends of the earth flowed somber under an overcast sky—seemed to lead into the heart of an immense darkness.” So whilst there may be some whisper of a racist intent to the Heart of Darkness as it may refer to native peoples in a seemingly negative light, this example from the text demonstrates that the novel in its entirety is a critique on imperialism.