Some experiences from the time of World War One have been worked into "For Whom the Bell Tolls". According to Anthony Burgess, the farewell at the station on page 434 is the equivalent of Hemingway's departure to the Italian front. An interesting aspect is that Jordan went to school instead, maybe the war represents for Hemingway, as well as for his character Jordan, a part of his education. The last thoughts of Jordan could refer to Ernest's wounding in Fossalta where it seemed to him "more natural to die than to go on living"(Burgess (9.), p. 22). The gray-haired soldier who already appeared (From Boy to Man) might have been the prototype of Anselmo, while Golz's look is that of real life Polish General "Walter", commander of the XIVth International Brigade.
To his other fiction, there are parallels, too. Maria's appearance and her behavior are almost identical to Catherine Barkley's. When Robert first embraces her, she erupts in tears, later she stated she didn't care much about herself but wished to do everything for him, and that she was his wife. Like Catherine, she is very preoccupied with death, and even excels her here. It seems as though Hemingway tried to summon the spirit of "A Farewell to Arms" once again, but Maria never was a character as complex as Catherine. In fact, she rarely said or did anything, and at the beginning of the last quarter of the novel Robert even remarked "I know thee very little from talking"(For Whom (5.), p. 365). She appears to be an imitation of Ms. Barkley, but only the facade is identical, in Maria's case, there is nothing behind, except for the story about her parents, but anyone could have told that. Pilar will be discussed in greater detail below (Pablo).
The story is told by a third-person selective-omniscient narrator and contains far more inner monologue and remembrances of the various characters than "A Farewell to Arms". This, on the one hand, is a necessity, since the book deals with just four days, and on the other hand supports the author's intention to illustrate the diversity and complexity of Spain. By using medieval English he emphasizes the antiquity and formality of the Spanish language and tries to lift the novel onto the level of Shakespearean dramas. In the last part of the novel, the plot is split into two parallel actions, the preparations for the attack and the course of Andrés. This is no unusual technique of storytelling, but with Hemingway, who sharply focused on his protagonist in "A Farewell to Arms", it's a signal. Some say it's a signal of him giving in to the demands of Hollywood directors who wanted books that can be easily used as scripts, but I consider it a signal of him disassociating himself from the protagonist, maybe because of superstition (it brings bad luck to write about one's own end), but more likely because of his inner struggle that will be explained later (Pablo ). At the time the novel was published, it seemed as though he separated the narrator from the protagonist to become what he had always wanted to be: A big, omniscient and ubiquitous daddy who tells all the stories and who's got everything under control. The reader often gets the impression that the characters are the narrator's children, especially when he evaluates them ("Anselmo was a very good man"(For Whom (5.), p. 212), "This was the greatest gift that he [Robert] had, the talent that fitted him for war"(For Whom (5.), p. 421),etc.).
The main theme of the novel is, as already pointed out in its preface, intense comradeship in the prospect of death, the giving up of the own self for the sake of the cause, for the sake of the people. Robert Jordan, Anselmo and the others are ready do it "as all good men should", the often repeated gesture of embracing or patting on one another's shoulder reinforces the impression of close companionship. One of the best examples is Joaquín. After having been told about the execution of his family, the others are embracing him and comfort him by saying they were his family now. Besides this love for the comrades, there is the love for the Spanish soil, which is represented by the pine-needled forest floor. This love lasts till the very last breath, as the last picture proves. Robert Jordan awaited his death feeling "his heart beating against the pine needle floor of the forest"(For Whom (5.), p. 504).
A less obvious, but, for the author personally, more important theme is suicide. Alarmingly enough, Hemingway already tried to justify it. Maria and Karkov are always equipped to do it, and Kashkin made Robert do it. The characters, including Robert, would prefer being dead to being captured, and that is Hemingway's first step onto a downward spiral.
Hemingway frequently used images to produce the dense atmosphere of violence and death his books are renowned for, the main image of "For Whom the Bell Tolls" is the machine image. The fear of modern armament destroys, as it already did in "A Farewell to Arms", the conceptions of the ancient art of war: combat, sportsmanlike competition and the aspect of hunting. Heroism becomes butchery, the most powerful picture employed here is the shooting of Maria's parents against the wall of a slaughterhouse. Glory exists in the official dispatches only, the theme "disillusionment" of "A Farewell to Arms" is adapted.
Especially the fascist planes are dreaded, when they approach, all hope is lost, the efforts of the partizans seem to vanish, their commitment and their abilities become meaningless. "They move like mechanized doom"(For Whom (5.), p. 93), and they wreak havoc with El Sordo and his band, the ideological slogans Joaquín employs "as though they were talismans"(For Whom (5.), p. 328) have no effect, he resorts to praying, but not even that can save him. Every time the planes appear they indicate a certain and pointless death. The same holds true for the automatic weapons ("Never in my life have I seen such a thing, with the troops running from the train and the máquina speaking into them and the men falling"(For Whom (5.), p. 31)) and the artillery, especially the trench mortars that already wounded Lt. Henry ("he knew that they would die as soon as a mortar came up"(For Whom (5.), p. 330)). No longer would the best soldier win, but the one with the biggest gun. The soldiers using those weapons are simple brutes, they lack "all conception of dignity"(For Whom (5.), p. 349) as Fernando remarked, Anselmo insisted "We must teach them. We must take away their planes, their automatic weapons, their tanks, their artillery and teach them dignity"(For Whom (5.), p. 349).
Apart from this physical threats, much of the violence is executed on a metaphysical level. The arguments between Robert and Pablo, especially the one where Robert tried to provoke Pablo far enough to have a reason to shoot him, is a great metaphysical battle that reminds one of Edward Albee's "Who's afraid of Virginia Woolf?", where the two main characters cause each other to crack up just by provoking. Pilar also is a very good example for metaphysical violence. She is one of the most brutal characters in the whole novel, and hurts almost everybody, but never actually uses physical force.