What are the differences and similarities between Ma Joad in The Grapes of Wrath and Catherine in A Farewell to Arms?

Ma Joad of The Grapes of Wrath and Catherine of A Farewell to Arms are similar in their beliefs in the power of love and in their inner strength in the face of tragedy. However, they differ in their sense of traditional Christian values and the sense of family and human brotherhood.

Ma Joad's one aim in life is to preserve her family and ensure its survival. But, she also believes in helping others. As they begin their exodus from Oklahoma, Ma tells her son Tom,

“You got to have patience. Why, Tom—us people will go on livin’ when all them people is gone. Why, Tom, we’re the people that live. They ain’t gonna wipe us out. Why, we’re the people—we go on.” (Ch. 13)

After Ma stresses the point that people will always survive, and in humanity lies hope rather than in things like food and shelter, she exemplifies this concept as the family has a Mr. and Mrs. Wilson join them on their journey after Al and Tom repair their car.

On the other hand, Catherine Barkley loves Frederic for protection from the "gloom and doom" of the war around them. In fact, she has originally taken a position as a nurse in the hope that her wounded husband might enter the hospital where she is located, so her motives are not nearly as altruistic as those of Ma Joad.

Yet, although Ma Joad and Catherine channel their love in ways that differ, they both hold themselves calm in the face of adversity. Ma tells her son Tom not to fight the ejection from their home by himself or only with a few others because he will be hunted down:

Tommy...They say there's a hun'erd thousand of us shoved out. If we was all mad the same way, Tommy-they wouldn't hunt nobody down-...." (Ch.8) 

In the end of Hemingway's novel, Catherine, too, exhibits much strength of character. She tells Frederic, who calls her a "dear, brave sweet" as she faces death:

"Don't worry, darling,..I'm not a bit afraid. It's just a dirty trick." (Ch.41)

Both Catherine Barkley and Ma are healers. But, whereas Ma demonstrates her faith that people can survive and adapt by performing acts of charity and encouraging and helping to heal others with prayer and words, Catherine channels her charity through physical acts of nursing only, although she often works long hours. Later, she tells only Frederic that he is her "religion."

Catherine Barkley and Ma Joad are two brave women, but they differ ideologically in some areas. Catherine seeks to find a secure world for herself and Frederic Henry with her passionate love. On the other hand, Ma Joad extends hope and strength to others with her charitable love and moral strength.