kindness, Muley says, "if a fella got somepin to eat and another fella's hungry—why the first fella ain't got a choice." Here, Steinbeck is emphasizing the necessity of, and glorifying the selflessness of, co-operation and solidarity among the working classes. This is the same message which Steinbeck conveys in much of hisfiction, the most notable other example perhaps being Of Mice and Men.

Muley is also a significant character because he helps Steinbeck to emphasize the desolation and ghostly emptiness of the land once it has been abandoned. He wanders this land after almost everybody else has left and calls himself "a damn ol' graveyard ghos'." This sense of ghostly desolation arguably suggests the slow death of the working classes under the merciless, dehumanizing ideology of Capitalism. Muley Graves is, in this sense, a personification of the figurative death of the working classes. Indeed, even Muley's surname, Graves, connotes death.

Muley's primary purpose in Grapes of Wrath is to provide a contrast to the Joad family and to keep the veil up that would otherwise have fallen with the Joads' departure over life in Oklahoma. Muley is stubborn (hence, the name Mule-y) and pessimistic, both of which drive him to negative destructive action as opposed to positive upbuilding action. He is also bound by these traits to the inability to admit a mistake, which, if he could have done so, would have sent him to California in pursuit of his wife and children. In addition, Muley's presence in Oklahoma gives a view into the lives of those who chose to remain, The landowners are driven to such cruelty that Muley, for one, hides and sleeps in secret run down places and set his strength and energy to making the landowners miserable with difficulties. This creates the feeling in Muley that he might be going insane, which metaphorically brings up the the question of whether extreme pessimism can even be a sane, rational choice when faced with adversity.