In the Heart of Darkness Joseph Conrad explores the degradation of human morality as symbolized by Marlow's journey towards the "heart of darkness." As Marlow "penetrates deeper and deeper into the heart of darkness," and farther and farther into the African wilderness, he probes further into the human subconscious and psyche, represented by the jungle. Marlow's experiences in the jungle, and the episodes of barbarism, depict what happens when man crosses the line of civility.