What are Toms dilemma between being good and naughty in chapters 17-24 ?

When Tom returns home and sees Aunt Polly crying over his death, he realizes that one of his fantasies of being "dead temporarily" has been fulfilled. Previously, Tom had wished to be dead when he had been full of self-pity. His idea was to make those who had hurt him suffer in guilt and regret for treating him in the wrong manner. He gets exactly what he wished for: Aunt Polly is heartbroken over mistreating him, and even Sid seems sorrowful. But Tom realizes that this scene provides him little comfort, for he feels nothing but pity for Aunt Polly and her sufferings. Thus, he chooses to return home... the right choice.

Now the boy stole out, rose gradually by the bedside, shaded the candle-light with his hand, and stood regarding her. His heart was full of pity for her. He took out his sycamore scroll and placed it by the candle. But something occurred to him, and he lingered considering. His face lighted with a happy solution of his thought; he put the bark hastily in his pocket. Then he bent over and kissed the faded lips, and straightway made his stealthy exit, latching the door behind him.