In The Adventures of Huckleberry Finn, what is the reason for including in the narrative the detail of Huck's Pap being an alcoholic?
Pap Finn's drunkenness points to what a sordid character he is in the narrative of The Adventures of Huckleberry Finn, for he is fonder of the bottle than he is of anything or anyone else.
1. Pap Finn serves as an ironic foil to Jim; as a drunken reprobate who beats his son, Pa is representative of the poor white "buckra" who felt that they were superior to blacks. Having abandoned his son, Pa returns in Chapter IV and berates Huck for knowing how to read,
"You think you're better'n your father, now, don't you, because he can't? I'll take it out of you. Who told you you might meddle with such hifalut'n foolishness, hey? who told you you could?”
Having heard rumors of Huck's coming into money, Pap insists upon having it. But, Huck tells him he does not have any money, the judge does; so, Pap goes to Judge Thatcher's, where the judge tries to reform him. Instead Pap leaves and returns to Miss Watson's place. After Miss Watson tells him to stop bothering her place, Pap kidnaps Huck and locks him in a ramshackle cabin. However, Huck manages to escape.
In contrast to Pap, who complains of the worthlessness of the blacks, the runaway slave Jim is a steady man, caring, and loving--a better father to Huck that Pap in many ways. In contrast to Pap, who kidnaps his son for money, Jim cries when he thinks that he and Huck have been separated after cutting the wrecked steamboat loose. In Chapter XV, when Huck makes it back to the raft, he decides to play a trick on Jim and pretend that he has been there all night. Jim awakens and is elated to see Huck, unlike Pap, who berates and abuses him,
Lemme look at you chile, lemme feel o’ you. No, you ain’ dead! you’s back agin, ’live en soun’, jis de same ole Huck—de same ole Huck, thanks to goodness!”
But, when Huck persuades Jim he has dreamed that they were separated, the superstitious Jim feels the need to interpret the dream. Finally, then, Huck must convince him of the truth by showing him the leaves and debris on the raft. Hurt and angered that Huck has made a fool of his loving feelings, Jim scolds Huck, telling him he is like the trash on the raft for toying with his sincere feelings,
...."En when I wake up en fine you back agin, all safe en soun’, de tears come, en I could a got down on my knees en kiss yo’ foot, I’s so thankful. En all you wuz thinkin’ ’bout wuz how you could make a fool uv ole Jim wid a lie. Dat truck dah is TRASH; en trash is what people is dat puts dirt on de head er dey fren’s en makes ’em ashamed.”
2. Furthermore, Pap serves as an example to Huck of what he does not want to become: an outcast of society and a selfish failure, unlike Jim who risks his freedom to help the doctor save Tom Sawyer in the last chapters. It is from Jim, then, that Huck acquires his more sympathetic nature towards others. This sympathy is what saves Huck from becoming selfish and cruel like his father in his habits.