Jem gave a reasonable description of Boo: Boo was about six-and-a-half feet tall, judging from his tracks; he dined on raw squirrels and any cats he could catch, that’s why his hands were bloodstained—if you ate an animal raw, you could never wash the blood off. There was a long jagged scar that ran across his face; what teeth he had were yellow and rotten; his eyes popped, and he drooled most of the time.
Jem describes a version of Boo Radley that is essentially a monster from a horror story. This description reflects the children’s preconceived notions about who or what Boo might be. They have filled in the void created by their curiosity with all of the most dreadful and frightening things that they can imagine. The notion of Boo as an innocent, and in fact quite vulnerable, human being has not yet occurred to them at this early stage in the novel.
Arthur Radley just stays in the house, that’s all...Wouldn’t you stay in the house if you didn’t want to come out?
Miss Maudie is speaking to Scout and Jem and trying to make them see things from Boo Radley’s perspective. At this early point in the novel, it is very difficult for the Finch children to deal with the unknown. Because they are young and imaginative, they have come up with all sorts of outlandish reasons why Boo might not want to ever leave his home, but Miss Maudie suggests that the reason is much more simple and easy to understand.
I looked from his hands to his sand-stained khaki pants; my eyes traveled up his thin frame to his torn denim shirt. His face was as white as his hands, but for a shadow on his jutting chin. His cheeks were thin to hollowness; his mouth was wide; there were shallow, almost delicate indentations at his temples, and his gray eyes were so colorless I thought he was blind. His hair was dead and thin, almost feathery on top of his head.
Scout is describing Boo Radley at the end of the novel when she sees him for the first time. Words like “khaki,” “gray,” “delicate,” and “thin” all reflect how physically unimposing and nonthreatening Boo actually is, as compared to the monstrous form that Boo took in the Finch children’s imagination. Note that this description follows almost the same pattern as the description of Boo from the beginning of the book describing the same features like hands, face, mouth, and eyes.
These words, spoken at the end of the book, are the only words that Boo Radley speaks in the entire novel. The words capture his character in its entirety. Boo is someone who wants to spend his life with in the protective walls of his home. He has ventured out because of a desire to protect the Finch children, but he is not interested in becoming part of society. This request provides Scout her first opportunity to fully interact with Boo as a human being.