The way how a human person exists and develops is controlled by the circumstance he born and the social economic forces he or she has to deal with。 Only the fittest survivals in the life can live in this society。 Because freedom of will dose not exist, ethical choices are illusory。 Naturalism thus eliminates the ethical problem that lies at the heart of the realist novel。 Since human behavior is determined, it cannot be judged in terms of right or wrong, good or bad。 Such an idea is presented in Sister Carrie, the way how Carrie improves her social status and then enters the upper-class is to be the mistress of Drouet and Hurstwood, which is conventionally considered as an immoral way。 Different from the then-popular idea that such a girl should be punished, Dreiser insists to follow the truth and frees Carrie from punishment。

As Dreiser entered the literary scene in the early 1900s, a conventional style of writing had already been set into tradition。 It was wildly accepted that the function of literature was to appeal to man’s higher nature, to inspire him through the depiction of man’s capacity to achieve the ethical life to seek such a life for him。 Materialism and capitalism in a booming economy, conventional standards of men and women’s roles, and the denial of the American public in response to the novel all prove that Sister Carrie was ahead of its time in portraying the authentic and pessimistic view of real existence。