Jim Casy exists as the philosopher, the motivator and the voice of reason in The Grapes of Wrath by John Steinbeck. The ex-preacher is used to express some of the book's major themes, explicitly articulated in his actions. Jim Casy, by fulfilling his predominant role as the novel's guiding moral voice, establishes not only a sense of god, but also one of morality and justice.

Jim Casy is an ex-preacher who is unsure of how to use the talents he possessed as a preacher, if not as the leader to a flock of Christians. He is a fluent and persuasive speaker and spiritual healer but no longer appreciates his talents. By the end of the novel he learns to apply them towards organizing the migrant workers. He comes to believe so deeply in his goal of saving the tormented workers that he gives his...