The distinct difference between the casual and youthful style of Huck’s narration in Huck Finn and the dark and moralistic tone of the novel enables the book to work on two levels. While Huck’s narration is breezy and generally optimistic, the events he describes and witnesses are often violent, depressing, and indicative of the worst of human nature. An astonishing number of bodies pile up as Huck and Jim make their way down the river. Nearly all of these deaths are the result of human flaws, rather than acts of nature. Twain makes it clear that most of the characters died in foolish pursuit of unworthy causes, such as the Grangerfords, who sacrifice most of their children to a pointless feud. Similarly, the speech Colonel Sherburn gives when the mob comes to lynch him is deeply pessimistic about human nature and civilization: “the average man’s a coward…The pitifulest thing out is a mob; that’s what an army is – a mob.” By contrasting this dark, cynical tone with Huck’s innocent optimism, Twain makes Huck’s inevitable loss of innocence feel poignant.
The tone of Huckleberry Finn is also moralistic, most clearly on the theme of slavery. Over the course of the novel, Huck asks questions and confronts moral dilemmas that enable him to see the basic injustice of slavery, if only as it pertains to Jim. Although Huck never explicitly realizes that the larger institution of slavery is morally deplorable, the novel on a whole functions as a moral argument for emancipation. Early on, Huck tries to explain to Jim why some people speak French. Jim insists that all men are essentially the same, asking, if a Frenchman is a man, “Dad blame it, why doan he talk like a man?” Jim’s insistence on the equality of all men can be extended to an argument against slavery, as “all men are created equal.” The tone of questioning is sustained throughout the novel, as Huck is forced to confront his basic assumptions about humanity, not only in terms of slavery, but also about class. The king and duke satirize the idea of nobility, and about what it means to be a truly “sivilized” human being.