How does Marlow's journey into the "heart of darkness" symbolize a voyage of self-discovery?
Marlow's journey into the enigmatic, dangerous Congolese jungle in search of Kurtz symbolically represents his discovery of mankind's inherent wickedness. While Marlow literally travels from Europe to Kurt'z station located in the depths of the Congolese jungle, he metaphorically embarks on a journey to discover mankind's inherent nature. At the beginning of his journey, Marlow has naive conceptions of European culture and believes that Europeans are the beacons of civilization, educating and helping "savages" become modernized. As Marlow's journey progresses, he witnesses the inefficiency, greed, and incompetence of the Company and its employees. Despite the negative perception of the Company, Marlow believes that Kurtz is the exception and anticipates meeting a civilized, refined individual. Unfortunately, Marlow discovers that Kurtz is a debased, fanatical person, who rules as diety in the Congolese jungle. His lack of civility and unrestrained desire indicate his corrupted spirit. By the end of his journey, Marlow gains insight into the wicked nature of mankind and realizes that civility is simply a thin veil covering a corrupted, sinful heart.
The Heart of Darkness is to be understood as a literal journey into the Congo (a physical darkness) as well as a metaphorical journey into the heart of the individual. In the novella, the individual is Marlow. We have evidence of this being a journey of self discovery by the comments that Marlow inserts while narrating the literal journey. This metaphorical journey is double layered as Marlow tells the reader the story of Kurtz. Immediately Marlow identifies himself with Kurtz. The difference being that Marlow does not succumb to the darkness which may be found in every man's soul as Kurtz has.
Marlow's discovery of Kurtz is shrouded in mystery. Slowly Marlow learns who Kurtz was and who Kurtz became as well as learning about himself. He gets close enough to the edge to peer into the darkness but does not fall into it. They mystery of Kurtz and the process of learning about him can also symbolize the process of learning about one's self.