The Psychological Journey

The reader's own journey into the "heart of darkness" is governed entirely by Marlow's subconscious. We see the Congo with all its wonders and horrors through the memories of Marlow as he relives his own personal journey and encounters all the emotion and pain that he left behind in the Congo. Further,  since the prominence of this journey lies within it being a psychological one, the reader must understand that every minute detail that Marlow conveys to his audience is underscored by the deeply seated beliefs and emotions that Marlow had while traveling. Therefore when one takes this concept into account, we are left with a brilliant depiction of a man's journey into his subconscious as he grapples with the painful experiences and emotions that the Congo left him with.