LitCharts assigns a color and icon to each theme in A Farewell to Arms, which you can use to track the themes throughout the work.
War
Love and Loss
Reality vs. Fantasy
Self vs. Duty
Manhood
Religion
Summary
Analysis
After dinner, Henry and the priest talk in Henry's room. The priest thinks that now that the destruction from the war is apparent, both sides will eventually stop fighting. Henry disagrees, and argues that the winning side will never give up. Henry says that it is only in defeat that people become "Christian," or gentle. He adds that he no longer believes in victory or defeat. The priest asks what Henry does believe. He answers that he believes only in sleep.
Henry's thoughts about religion are deeply cynical. He no longer believes in the idea of war. Henry's belief only in "sleep" shows how literally fatigued he has become. It also suggests that war has made him only believe in death.