In Heart of Darkrness, there are many indications of Kurtz's mental illness. The decapitated heads on poles outside his home, his "exterminate all the brutes" philosophy, and his obsessive quest for ivory show his "unsound method," as the manager terms it. Is Kurtz mad, or has he simply adapted to a barbaric society? Is he just playing by the rules of the jungle, which differ from those of a civilized society?
Also..
Kurtz appears in Heart of Darkness for a very short time. He does and says little. Why then is he so important to the story? Why didn't Conrad expand his actual role? Does his limited appearance detract from his importance?