Although naturalist novels such as The Red Badge of Courage and The Call of the Wild are now considered classics, critics are often torn on the merits of the movement as a whole. The movement was initially met with suspicion because it was regarded as irrelevant to the American culture and its values. Perhaps because of its French roots, Naturalism was perceived as having little to offer an American readership. The lack of a strong morality presented in many naturalist novels further alienated critics and readers who looked to literature to enlighten and inspire. In his book Realism and Naturalism in Nineteenth- Century American Literature, Donald Pizer provides a retrospective comment: “We are coming to realize that a generation of American critics has approached American literary Naturalism with beliefs about man and art which have frequently distorted rather than cast light upon the object before them.” Conservative reviewers denounced the works of Dreiser, for example, for his unfavorable depiction of the modern American man and woman. Still others, like Joseph Warren Beach in his book The Twentieth Century Novel: Studies in Technique, praise Dreiser for his negative depictions. Beach commends Dreiser’s “fearlessness, his honesty, his determination to have done with conventional posturings and evasions.”

In the 1940s and 1950s, critics were quick to distance themselves from naturalist writers because some of them (such as Dreiser) were associated with the Communist Party. During that time, there was intense distrust of anyone with communist leanings. Today, critics legitimize the movement on its own terms, crediting it as a significant and coherent movement that resulted in great literary works.

Many critics have difficulty discussing Naturalism without reference to its predecessor, Realism. The two movements share many characteristics (such as attention to detail, common people as subjects, and portrayals of harsh circumstances), but most scholars see Naturalism’s reliance on the principle of determinism as its main distinguishing feature. This refers to the belief among naturalist writers that people’s fates are determined by their environments and/or their genetics. Pizer declares:

The common belief is that the naturalists were like the realists in their fidelity to the details of contemporary life but that they depicted everyday life with a greater sense of the role of such causal forces as heredity and environment in determining behavior and belief.

Critics find Naturalism to be the more pessimistic of the two movements. Pizer comments that another important difference is the way human nature is perceived. He explains:

A naturalistic novel is thus an extension of Realism only in the sense that both modes often deal with the local and contemporary. The naturalist, however, discovers in this material the extraordinary and excessive in human nature.

Critics like Pizer find Naturalism to be empowering because it reveals the humanity, experiences, and emotional states of common and lowly characters.