Heart of Darkness Part II, Section 1 Analysis (pages 91-99)
Conrad uses the phrase "heart of darkness" in various forms throughout the book, but by this point in the story he really starts using it a lot, and almost always in connection with the wilderness (remember, however, he says the same about London too). Conrad, via Marlow, also lends the wilderness an anthropomorphic aspect: " 'It was the stillness of an implacable force brooding over an inscrutable intention' " (95). He also says it has " 'a vengeful aspect' " (95). The vengeful aspect is reminiscent of a deity, especially because the fireman savage thinks the steamer contains a vengeful spirit.
The theme of terrible knowledge is again touched upon on p. 95 when Marlow tells the men listening to his story, "The inner truth is hidden—luckily, luckily." This also relates to the seemingly insane displays performed by the natives—displays Marlow feels he could take part in. He rationalizes this by saying, "The mind of a man is capable of anything—because everything is in it" (98). This is a significant quote because it foreshadows what happens to Kurtz and the range of mind states he passes through.