At the beginning of Chapter 20, Dolphus Raymond gives Dill a drink from his paper bag to settle his stomach. In doing so, Dill and Scout find out that Dolphus Raymond drinks Coca-Cola from his paper sack instead of alcohol. Dolphus then explains why he feigns alcoholism. He tells the children that when people believe that he is an alcoholic, it gives them a reason to grab onto which helps them come to terms with his way of life. Dolphus realizes that the prejudiced community of Maycomb disagrees with his lifestyle. Dolphus freely associates with the black community and even has several mixed children. In 1930s Alabama, interracial relationships were considered taboo. Dolphus does not want to continually explain why he chooses to associate with black members of his community and also wishes to avoid conflict with his prejudiced neighbors. Dolphus finds it easier to feign alcoholism and let people blame his lifestyle on liquor rather than continually defend himself.
Outside the courthouse Dolphus Raymond reveals to Dill & Scout that the drink in the brown paper bag is not actually whiskey but coca-cola and that he is not actually a drunk. He swears the children to secrecy as he explains his reasons for pretending to be half-drunk all of the time:
"Some folks don't - like the way I live. . . (..) but I don't say the hell with 'em, see? (..) I try to give them a reason (...) if I weave a little drink out of this sack, folks can say Dolphus Raymond's in the clutches of whiskey - that's why he won't change his ways. He can't help himself, that's why he lives the way he does". (Lee, 200)
Dolphus is a well-off man who has an affair with a woman of colour and has many children with her. Many people judge him for these actions and look down on the choices he has made but blaming it all on alcoholism makes everything more acceptable somehow.
It provides Dolphus the freedom to live how he wants without having to explain himself. If people were to know that he had, in fact, made a completely sober decision to have the affair and the children, they would judge him very harshly. For now no one tries to scratch the surface to see what is really underneath and are happy to form judgements based on perceptions. His decisions seem less unfortunate because he is a 'drunk'.
This small but poignant incident at the courthouse falls in with the theme running through the entire book: "the simple hell people give other people - without even thinking" (Lee, 201). People are quick to form judgement or to believe in stereotypes without bothering to take the time to know other people or to understand their motives.