Psychological Significance Of Journey

Marlow's journey to the heart of darkness is undoubtedly a physical trek and the readers are fully aware of this. What the readers might dismiss from their thoughts is the psychologically devouring trip that this journey presents. The jungle is physically survivable but is it mentally sustainable? Marlow hints at mental surrendering but continues on his journey through the Congo. Personally, I think that the mental challenge is far more difficult than that of the physical.