Darkness as it is perceived by the characters in Joseph Conrad's novella, Tim O"Brien's short story, and Francis Ford Coppola's movie, is largely dictated by society. The more modern civilizations of Great Britain and America respectively, have instilled in their people, that darkness is an entity that is attached to civilization, or lack thereof. Thus, the dark side of human nature is thought only to exist in those people who have not been graced with the presence of a government, written language, and other essentials necessary to exist as what is believed to be a "pure" human being. In these works, darkness collectively refers to something that remains an enigma in written word, but is often attached to brutal killings, and truth in its barest, and perhaps most callous form. A clearer sense of darkness is gained once a civilized person witnesses one of their own cross into that darker side of human nature, this transformation shown in the three works sheds light onto the enigma that is darkness. .
Nature, or the jungle is a main character in each of these works. While there is a distinction between darkness of the human heart, and that of nature, this primal setting helps to blur the certainty. The jungle is a place where the "earth [seems] unearthly" (Conrad, 105), where it is teeming with life, and reeking of death all at the same time. The isolation that the jungle creates for the characters plays a crucial role in their behavior, as it seems to intensify their experience. The jungle, like darkness, contains a mystery within its lush green leaves. The atmosphere of unknown in a foreign place (Vietnam or the African Congo) creates for an unprecedented amount of fear, even in such trained men as Marlow, Kurtz, and Captain Willard. Thus, a man becomes more vulnerable to his surroundings and eventually succumbs to his surroundings and discovers his darkness.
In all three accounts Mary Anne and the respective Kurtzes are almost exaggerations of an ideal.