Adventures of Huckleberry Finn explores themes of race and identity. A complexity exists concerning Jim's character. While some scholars point out that Jim is good-hearted and moral, and he is not unintelligent (in contrast to several of the more negatively depicted white characters), others have criticized the novel as racist, citing the use of the word "nigger" and emphasizing the stereotypically "comic" treatment of Jim's lack of education, superstition and ignorance. At the same time, readers should understand that this book was made during the mid 19th century during the Civil War so the term "nigger" was used quite often without punishment.
Throughout the story, Huck is in moral conflict with the received values of the society in which he lives, and while he is unable to consciously refute those values even in his thoughts, he makes a moral choice based on his own valuation of Jim's friendship and human worth, a decision in direct opposition to the things he has been taught. Twain, in his lecture notes, proposes that "a sound heart is a surer guide than an ill-trained conscience" and goes on to describe the novel as "...a book of mine where a sound heart and a deformed conscience come into collision and conscience suffers defeat".
To highlight the hypocrisy required to condone slavery within an ostensibly moral system, Twain has Huck's father enslave his son, isolate him, and beat him. When Huck escapes, he then immediately encounters Jim "illegally" doing the same thing. The treatments both of them receive are radically different, especially in an encounter with Mrs. Judith Loftus who takes pity on who she presumes to be a runaway apprentice, Huck, yet boasts about her husband sending the hounds after a runaway slave, Jim.
Some scholars discuss Huck's own character, and the novel itself, in the context of its relation to African-American culture as a whole. John Alberti quotes Shelley Fisher Fishkin, who writes in her 1990s book Was Huck Black?: Mark Twain and African-American Voices, "by limiting their field of inquiry to the periphery," white scholars "have missed the ways in which African-American voices shaped Twain's creative imagination at its core." It is suggested that the character of Huckleberry Finn illustrates the correlation, and even interrelatedness, between white and black culture in the United States.