The theme of "Poverty" is obviously related to the theme of "Society and Class." But while the "Society and Class" theme is concerned with showing how the social class system is basically just invented by society to justify the status quo, Dickens is also very concerned in showing just how miserable the lower classes really were. With Oliver Twist, he doesn’t shy away from depicting the conditions of the poor in all their misery with gritty realism.
Dickens uses a distant, journalistic tone when describing poor neighborhoods to add to the realism of Oliver Twist, but the distance has the additional effect of making it occasionally difficult to sympathize with the poor.
Dickens occasionally describes members of the poorest class as sub-human or animal-like to highlight the huge chasm between the experiences of his middle class readers and the poor people he describes.