in chapter 31, Huck makes a decision in regarding Jim's slavery (to help him). how does Huck come to this decision.

A young man on the road tells him Jim, a runaway slave, was just captured and sold to the Phelps family, down the road. Huck sits down and contemplates his next move. He is torn between his friendship for Jim and his belief that helping a runaway slave is a sin. Huck finally writes a letter to Miss Watson explaining where Jim is. Not quite satisfied, he thinks about it some more, and, in one of the most dramatic scenes in the novel, rips apart the letter saying, "All right, then, I'll go to hell!"