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As is often the case with the comparison of stories, there are often more things that the stories don't have in common than what they do have in common. In this case, Ernest Hemingway's A Farewell to Arms is a story of an American man engaged in war, fighting with the Italians against the Germans. Wounded, he meets a nurse (Catherine), and when he abandons his military duties—refusing to fight in a war in which he no longer believes—he reunites with Catherine and they run away to Switzerland. There they grow more in love, and await the birth of their child. However, the relationship is doomed, much the way many of the soldiers are fated for death in fighting a war that has lost purpose for them also. In childbirth, the baby and Catherine die, and Henry is left alone.
Some themes in this story are individualism, identity, patriotism, and war.
In William Faulkner's short story, "Barn Burning," the story revolves around "Colonel" Sarty Santoris. His father, a sharecropper, has been accused of burning his "employer's" barn. Sarty's father expects his son to lie for him if asked, for the Ab Sartoris has burned down the barn. However, Sarty is not asked to testify and the case is dismissed because the judge feels there is not enough evidence against Ab, but Santoris is warned to leave the area. Ab is fine with this as he has already taken another job on the farm of a man named de Spain. Upon arriving, Ab finds himself in trouble again as a result of his disrespect for his employer's home, and Ab eventually decides to burn de Spain's barn as well. Ab suspects Sarty does not support his father's actions and tries to keep him locked up at home. Sarty escapes, warns de Spain, and then turns his back on his father's choices—decisions which create spirit-crushing problems for his family—and Sarty leaves without looking back.
Some themes in this story are alienation and loneliness, anger and hatred, loyalty and betrayal, morals and morality, and order and disorder.
However, themes common to both stories are that of choice and alienation. In both stories, Henry and Sarty face a moment when each must make a choice. Henry chooses to abandon his "post" with the army for he no longer believes in what he or the military is doing. Sarty also must make a choice when he must choose whether he will continue to live with his father and his criminal behavior that hurts the family over and over, or go away on his own. In both stories, as the characters leave, they become alienated from what they have known and must find their way separated from society.
If I had to write a thesis statement for this topic, it would be:
While William Faulkner's "Barn Burning," and Ernest Hemingway's A Farewell to Arms are stories with very different themes, there is one element present in both—the necessity to choose. Each of the main characters must make a potentially life-altering decision, and in doing so, they experience the alienation that comes in light of that choice.