Some characters in this novel are liberated and live happily ever after. Others aren’t able to escape the "labyrinth" that the city, their social class, and the systems of justice and religion seem to have created. Why is that? Certain characters seem to give up their free will at certain points, and to abandon themselves to a kind of bizarre fatalism. As much as Dickens wants to show how external influences turn people into criminals, the emphasis on fate in Oliver Twist seems to undermine that idea. How much free will does anyone have? Or is everyone just trapped in the systems of social class and religion, and unable to make any independent choices?
Although Dickens seems to be arguing that criminal behavior is the result of environment and influence, Nancy’s inability to leave her old life behind her suggests a kind of fatalism that undermines Dickens’s overall message.
Characters who fall asleep might give up their ability to choose, but that short-term passivity is not a concession to the fatalism that governs the actions of Nancy.