Twain uses the inhumane actions of Pap towards Huck to develop the theme."' I'll take you down a peg before I get done with you'" (Twain, 20). This quote by pap shows how man is inhuman to other men. Pap talks and acts mean towards Huck, even though Huck is his son. Not only is Pap mentally abusive toward Huck, but he is also physically abusive toward him. "But by and by pap got too handy with his hick'ry, and I couldn't stand it." Eventually Huck cannot stand it anymore as shown by this quote, "I was all over welts"(24) he eventually runs away. An example is when Pap gets mad at Huck because Huck can read and he can't. Pap realizes that Huck could be smarter and go further in life than he did and that frightens him. Pap reacts on that fear and abuses Huck therefore showing the connection between mans inhumanity to man and fear. Twain therefore uses fear as a major piece of the novel to ridicule society. Another example of this is the Grangerfords and the Shepherdsons, they fear each other and are afraid of each other so they are continually on the edge until one little incident makes one family make the first move because they fear the other, they don't even know what started the feud.
"What was the trouble about, Buck? -- land?" (120).
"I reckon maybe -- I don't know." (120).
"Well, who done the shooting? Was it a Grangerford or a Shepherdson?" (120).
"Laws, how do I know? It was so long ago." (120).
They even seek blood for revenge for accidental killing, "But he didn't git much chance to enjoy his luck, for inside of a week our folks laid him out." (120) They are so paranoid of each other that they kill each other because they think the family is going after them, with no regard to human life. Twain uses this to develop the argument that the cruelness of man contributes to social chaos, deceit and lies.
Twain uses greed and disregard of others to showcase mans inhumanity to man. An example of this is the dishonesty of the King and the Duke toward the Wilkes girls.