Themes are the fundamental and often universal ideas explored in a literary work.
Each of the characters in For Whom the Bell Tolls loses his or her psychological or physical innocence to the war. Some endure tangible traumas: Joaquín loses both his parents and is forced to grow up quickly, while Maria loses her physical innocence when she is raped by a group of Fascist soldiers. On top of these tangible, physical costs of the war come many psychological costs. Robert Jordan initially came to Spain with idealism about the Republican cause and believed confidently that he was joining the good side. But after fighting in the war, Robert Jordan becomes cynical about the Republican cause and loses much of his initial idealism.
The victims of violence in the war are not the only ones to lose their innocence—the perpetrators lose their innocence too. The ruffians in Pablo’s hometown who participate in the massacre of the town Fascists have to face their inner brutality afterward. Anselmo has to suppress his aversion to killing human beings, and Lieutenant Berrendo has to quell his aversion to cutting heads off of corpses.
War even costs the innocence of people who aren’t involved in it directly. War journalists, writers, and we as readers of novels like For Whom the Bell Tolls have to abandon our innocent expectation that wars involve clean moral choices that distinguish us from the enemy. Hemingway shows in the novel that morality is subjective and conditional, and that the sides of right and wrong are almost never clear-cut. With no definite sides of right and wrong in For Whom the Bell Tolls, there is no sense of glorious victory in battle, no sense of triumph or satisfaction that good prevails and evil is defeated.
Many characters die during the course of the novel, and we see characters repeatedly question what can possibly justify killing another human being. Anselmo and Pablo represent two extremes with regard to this question. Anselmo hates killing people in all circumstances, although he will do so if he must. Pablo, on the other hand, accepts killing as a part of his life and ultimately demonstrates that he is willing to kill his own men just to take their horses. Robert Jordan’s position about killing falls somewhere between Anselmo’s and Pablo’s positions. Although Robert Jordan doesn’t like to think about killing, he has killed many people in the line of duty. His personal struggle with this question ends on a note of compromise. Although war can’t fully absolve him of guilt, and he has “no right to forget any of it,” Robert Jordan knows both that he must kill people as part of his duties in the war, and that dwelling on his guilt during wartime is not productive.
The question of when it is justifiable to kill a person becomes complicated when we read that several characters, including Andrés, Agustín, Rafael, and even Robert Jordan, admit to experiencing a rush of excitement while killing. Hemingway does not take a clear moral stance regarding when it is acceptable to take another person’s life. At times he even implies that killing can be exhilarating, which makes the morality of the war in For Whom the Bell Tolls even murkier.
Even though many of the characters in For Whom the Bell Tolls take a cynical view of human nature and feel fatigued by the war, the novel still holds out hope for romantic love. Even the worldly-wise Pilar, in her memories of Finito, reveals traces of a romantic, idealistic outlook on the world. Robert Jordan and Maria fall in love at first sight, and their love is grand and idealistic. Love endows Robert Jordan’s life with new meaning and gives him new reasons to fight in the wake of the disillusionment he feels for the Republican cause. He believes in love despite the fact that other people—notably Karkov, who subscribes to the “purely materialistic” philosophy fashionable with the Hotel Gaylord set—reject its existence. This new acceptance of ideal, romantic love is one of the most important ways in which Robert Jordan rejects abstract theories in favor of intuition and action over the course of the novel.