Marlow, the narrator of Joseph Conrad's novella The Heart of Darkness, writes that Kurtz had made a report for the International Society for the Suppression of Savage Customs. The title of this organization implies that its intent was benevolence but that it was perhaps sinister in its practices.
Marlow writes of this report:
"...It was a beautiful piece of writing. The opening paragraph, however, in the light of later information, strikes me now as ominous. He began with the argument that we whites, from the point of development we had arrived at, 'must necessarily appear to them [savages] in the nature of supernatural beings--we approach them with the might as of a deity'" (page 111 of Heart of Darkness and Selected Short Fiction, Barnes and Noble Classics, 2003).
In other words, Kurtz's report recommends that whites appear to the Congolese as gods, and he follows this practice by establishing himself as a kind of god to the local people, only for the purposes of exploiting them.
Marlow also writes of Kurtz's report: "at the end of that moving appeal to every altruistic sentiment it blazed at you, luminous and terrifying, like a flash of lightning in a serene sky: 'Exterminate all the brutes!' (page 111). In a paper that is supposedly altruistic, or intended to help the local people, Kurtz seems to forget himself in the end, and his true nature comes out when he writes that all the natives should be killed. This paper reveals that Kurtz is like the devil, as he covers his evil intent with eloquence.