The Grapes of Wrath is most memorable as the story of the Joad family’s trek across Depression-era America. The long narrative chapters that trace their journey provide a personal context for understanding the more abstract social, historical, and symbolic musings of the shorter alternating chapters. Despite their sometimes preachy tone, these alternating chapters play an important role in the structure of the novel. Most notably, they extend the saga of migrant farmers beyond a single family, reminding the reader that the hardships faced by the Joads were widespread, afflicting tens of thousands of families in the Dust Bowl. Furthermore, these chapters anticipate the circumstances that the Joads will encounter: when the Joads come to the Hooverville in Chapter 20, for instance, the reader has already read a detailed description of these camps in the preceding chapter and thus foresees their difficulties.

Alternating between the Joads’ tale and more contextual musings outside the narrative also allows Steinbeck to employ a greater range of writing styles. It is true that Steinbeck successfully conveys a great deal of the Joads’ journey through spare, declarative prose and through the rustic dialect of the family members. However, the short chapters allow him to exceed the constraints of these prose forms, to root his story in a more universal tradition. At times, Steinbeck evokes the repetition and moral bluntness of biblical tales; at other moments, he assumes the clear, castigating tone of a soapbox politician; sometimes his style conjures up ancient epics of heroic deeds and archetypal struggles. Thus, the author roots his story in a more universal tradition, endowing it with significance that exceeds the individual characters and their specific setting.

Jim Casy is, in many ways, the novel’s guiding moral voice. He explicitly articulates many of Steinbeck’s thematic ideas, namely that human life is as sacred as any divinity and that a single life has little purpose unless it takes part in, and contributes to, a greater community. These ideas provide the foundation for the acts of charity and kindness that unify the migrant farmers as their lives grow harder and less forgiving.

Furthermore, Casy plays a vital role in the transformation of Tom Joad into a social activist. In many ways, Casy resembles a Christ figure: he is a man possessed of radical, controversial ideas; a champion of the poor and oppressed; and, in the end, a martyr for his beliefs. Tom’s newfound commitment to a better future indicates that Casy was correct in positing the power of selfless devotion to others: by joining the cause to help the people, and by inspiring others to join as well, Casy ensures his own immortality. Because he has merged his spirit with the whole of humanity, Casy lives on.

The book’s sense of realism results from its brutal setting. The migrants exist in a world characterized by dirt, dust, suffering, starvation, death, poverty, ignorance, prejudice, and despair. Steinbeck does not hesitate to provide honest details, many of which appear in the brief chapters of exposition and social commentary that intersperse the Joads’ story.

In contrast to the naturalistic setting, many of the characters in the Joad family stand as sentimentalized or heroicized figures. The realism of the nonnarrative chapters, some of which function like journalistic or cinematic reportage, balances this more romantic side of the novel by grounding the reader in the undeniably harsh and vivid surroundings. While Steinbeck’s frequent romanticism contributes to his novel’s epic proportion and import, his use of realism strengthens the novel’s effectiveness as a work of social commentary.