“Habit is habit, and not to be flung out of the window by any man, but coaxed downstairs a step at a time.”

The remark belongs to the chapter in which Tom Sawyer is being remade into a respectable schoolboy, and it is aimed at adults who assume that bad habits can be thrown off in an afternoon. Twain's answer, that an old custom has to be walked down the stairs one step at a time, argues for patience over willpower.