That noon, Aunt Polly immediately accosts Tom for lying to her. She has visited with Mrs. Harper (whose son Joe had told her everything) and found out that Tom had actually been over that night and overheard everything that he pretended was in a wonderful dream. In addition to Tom's lying to her is the humiliation she suffered from being made a fool of: "It makes me feel so bad to think you could let me go to Serena Harper and make such a fool of myself and never say a word."
Tom admits that his actions were mean, but he didn't intend to be mean; instead, he came over, he tells her, to let her know that she should not be uneasy about him. Aunt Polly believes it is another lie, but Tom is earnest that he came only "to keep you from grieving." Aunt Polly wants to believe him but is still cautious. Tom explains that when he heard them planning the funeral, he thought of the fun it would be to suddenly walk in and surprise everyone. This is the reason he didn't leave the note on the bark. Aunt Polly is surprised about the note, and after she sends him back to school, she goes to the closet to check his clothes. After vacillating back and forth about whether she should check for the note, she eventually does. Finding it, Aunt Polly's confidence in Tom's basic goodness is restored.
The scene with Aunt Polly encourages Tom to make up with Becky, and when he approaches her, she strangely rejects him and stomps away. He is confused by the incomprehensible actions of girls. Becky, meanwhile, has seen Alfred pour the ink over Tom's spelling book but decides not to tell so that Tom will receive a whipping.
While Becky is wandering about the classroom, she sees that Mr. Dobbins' top desk drawer is open. In it is a book on anatomy, which he reads when the class is busy with projects. All the students are completely entranced about the nature of the book, and Becky has the perfect opportunity to find out what the book contains. She looks about and, seeing that no one is around, removes the book with its handsome engraved and colored frontispiece and finds "a human figure, stark naked." At this moment a shadow falls across her book: It is Tom Sawyer. In her rush to conceal the book, she tears one of the pages. Now she is horrified because this offense will warrant a whipping in front of the entire class. She blames Tom and hurries from the room. Tom thinks a little licking isn't that important and decides to "let her sweat it out."
When school begins again, the ink spots on Tom's spelling book are revealed. Tom is accused and whipped, even though he stoutly proclaims his innocence. Ironically, Becky is not as happy as she thought she would be, and has to repress an impulse to inform on Alfred. She justifies her silence by assuming that Tom is going to reveal her guilt about the anatomy book.
Later in the afternoon when all are busy, Mr. Dobbins removes his book and discovers the torn page. When he asks the class who tore the book, no one volunteers, so he begins to question each student. When he reaches Becky Thatcher, she turns her head away, and when Mr. Dobbins orders her to look him in the face, Tom springs to his feet and says, "I done it."
Mr. Dobbins administers the most merciless flogging that he can. Tom, however, is consoled by the look of adoration in Becky's eyes. After the beating, he is forced to remain two hours after school, but he doesn't mind because he knows that Becky will be waiting for him. And, indeed, she is. She tells him of Alfred's treachery and her abetting it, but only her words, "Tom, how COULD you be so noble," have any lasting meaning for him.
Tom's character might be summed up in the statement that he makes when Aunt Polly chastises him for lying to her and, more important, letting her make a fool of herself in front of Mrs. Harper: "Auntie, I know now that it was mean, but I didn't mean to be mean. I didn't. Honest." His statement reflects the universal thoughtlessness and inconsideration that such youths have for the adult. Rather than detract from Tom's total worth, it merely confirms that his actions are those of most early adolescents. And to Tom's credit, he does acknowledge that his good joke now looks mean and shabby.
Even Aunt Polly would readily admit that the whole scheme had a certain flair and imagination about it and that, if she had not been the principal sufferer concerned, she could have laughed at the entire plan. Nevertheless, the simple truth remains that she was very hurt and frightened by this practical joke, regardless of its mastery. Her hurt is deepened by Tom's lying to her and allowing her to look foolish in the eyes of Mrs. Harper. She does, however, check out Tom's statement, and finding the note written on the bark, she knows again of Tom's basic goodness and love for her.
During the nineteenth century, it was a very common practice to use a paddle or some other instrument in order to whip children. Although boys were whipped frequently, young girls were virtually never whipped. Knowing this fact increases the horror of what Becky faces if it is revealed that she tore the anatomy book. Not only would it have been a horrible ordeal for Becky, who is basically sweet, to be beaten, but it also would have been a disgrace for her family. Tom's actions--accepting the blame for the torn page and taking the beating in Becky's place--redeem his character and are best summarized by Becky's simple statement "Tom, how COULD you be so noble."
The two incidents concerning the spilled ink on the spelling book and the torn page in the prized anatomy book make a parallel contrast to the earlier scene in which Tom hurt his Aunt Polly: Tom is falsely accused of spilling ink on his spelling book, and Becky could have easily saved him, but she remains silent. In contrast, Tom could have let Becky take her deserved punishment, but he cannot bear to have her distressed and humiliated; therefore, he nobly takes her punishment for her. In this contrast, Tom is seen as more kind and less spiteful than Becky.
Chapter 19 functions partly to make Tom aware of Becky's actions. Feeling contrite for how badly he has treated his Aunt Polly, he is able to return to school and offer an apology to Becky for ignoring her and her picnic. Chapter 20 presents the further estrangement between Becky and Tom. By the end of Chapter 20, however, everything is resolved between them, and we are ready for the later cave scene where the two youths will be lost together.
By following this chapter (The Cruelty of "I Don't Think") with the next (Tom Takes Becky's Punishment), Twain contrasts Tom's thoughtlessness in the first with his sacrifice for Becky Thatcher in the second.