The book holds a somewhat pessimistic view of human nature. It suggests that, despite surface appearances, human nature remains overwhelmingly subject to instinctual passions, emotions, and appetites – that essentially, it remains primitive. These primitive impulses are fully awakened in people like Kurtz in the midst of Africa, the so-called Dark Continent. In the general discourse of the age in which this novella was written, Africa was viewed very much as a hotbed of primitivism and savagery. However, it is the morally corrupt, materialistic, greedy Europeans who rush to plunder Africa's people and its natural resources that are seen as being the worst of all in this story.
Marlow issues a sobering reminder at the very start of the book that London, the heart of one of the supposedly most modern and advanced civilisations, is not necessarily as refined as it seems, or certainly has not been in the past:
'And this also,' said Marlow suddenly, 'has been one...
(The entire section contains 500 words.)