Marlow's change comes from within, a change in his idealism and his view of the people who work on the African river. At first, he is appalled by the squalor and disease present in the native people, and impressed by the Accountant, who keeps a proper, civilized appearance. However, as the story continues, he realizes that much of the horrors are endemic to the Imperialist mission itself; he sees a French ship firing into the underbrush with no actual target, and realizes that paranoia can drive men insane. Meeting Kurtz is the final blow to his belief system; Kurtz's total lack of empathy and his apparent insanity is contrasted with Kurtz's immense charisma and eloquence, showing Marlow that an educated and civilized man can have a "heart of darkness" and change under pressure. Without social norms, Kurtz's dark heart emerged and ruled his actions; Marlow sees that all men have the same potential, even himself, and his outlook is forever altered.