How does Dreiser implement Naturalism in "Sister Carrie"?

10)Money and capital are responsible for the actions of
humans rather than the more “pure” forces that regulated the lives of characters in
realist texts. Consider, for example, the idea presented by the narrator that, as stated
in one of the meaningful  href="http://www.paperstarter.com/sistercarrie.htm">quotations from “Sister
Carrie” by Theodore Dreiser, “A man’s fortune or material progress is very
much the same as his bodily growth. Either he is growing stronger, healthier, wiser, as
the youth approaching manhood, or he is growing weaker, older, les incisive mentally, as
the man approaching old age. There are no other states” (259). It could not be put in a
more concise way—clearly human nature is no longer molded by the forces of love,
feeling, or even rationality or reason. Instead of being shaped by nature and being able
to describe characters with microscopic precision, this becomes unnecessary when the
reader knows the motivation. A man is shaped by capitalism, the need to consume and all
other impulses become secondary.

11)Metaphorically
speaking, whereas realist text might have tended to focus on the jungle, Sister Carrie,
as an example of naturalism, concentrates on the sea. In other words, the jungle for the
realist novel would represent man in his primitive state, acting on natural desires and
impulses that were generally the result of emotion or other “pure” persuasion. The
jungle represents man as an individual, man surviving in a world that might not be
suited to his best intentions. With realism, every detail could be described with
perfect accuracy, everything reasoned out and the character would be inclined to act
according to a sort of internal reasoning. With Sister Carrie, however, the sea is the
object of interest. In this case, the sea represents the sea of people that crowd
together in urban areas. Unlike the jungle, this is a massive place where one could lose
the way or become drowned quite easily. In the sea, one must stand out because there are
so many other fish swimming, mostly with the current, in an effort to shine. While this
might be a dramatic and slightly abstract concept, put quite simply, the difference
between the jungle and the sea is that the desires are quite different. In the jungle,
it is an individual struggle close to the natural world. In the sea, however, there is
simply the struggle to stay afloat and not get lost.