The title of For Whom the Bell Tolls is a direct allusion to a famous excerpt from John Donne's poetry anthology Devotions Upon Emergent Occasions. The poem ends thus: "Each man's death diminishes me, / For I am involved in mankind. / Therefore, send not to know / For whom the bell tolls, / It tolls for thee."
This poem draws on themes of common humanity and interconnectedness, particularly in relation to death. The tolling bell represents a death knell, alluding to church bells often rung during funerals in European tradition. Donne states in his poem that one should not ask "for whom the bell tolls," or whose funeral occurs, because the bell should toll for the listener. When one person dies, Donne asserts, all other human beings should feel that death as if it were their own. Thematically, this premise relates to Jordan's personal misgivings around war and death. He does not entirely shy away from killing, but he does experience misgivings about it, questioning whether or not his morals lie in the correct place. While Jordan might agree with Donne that "each man's death diminishes me, / For I am involved in mankind," he knows that some death will be necessary to achieve his goals. This contradiction causes him strife.
In the following passage from Chapter 1, Hemingway includes an allusion referencing Francisco de Quevedo, a writer from Spain's baroque period (early 17th century to 1750s).
The old man turned toward him suddenly and spoke rapidly and furiously in a dialect that Robert Jordan could just follow. It was like reading Quevedo. Anselmo was speaking old Castilian and it went something like this, "Art thou a brute? Yes. Art thou a beast? Yes, many times. Hast thou a brain? Nay. None. Now we come for something of consummate importance and thee, with thy dwelling place to be undisturbed, puts thy fox-hole before the interests of humanity."
Quevedo utilized conceptismo (conceptism) as a primary poetic style. This form of poetry focuses on paradoxically simple language, imbued with multiple possible meanings. Anselmo's speech, following Jordan's observation, has been translated into older-sounding English to imitate the tone and impression of Anselmo's words.
This multiplicity of meanings, conceptismo, plays out on multiple levels in For Whom the Bell Tolls: the moral complexity of war, Jordan's unconfirmed fate, even Hemingway's own use of language. The tone of the novel is one of indecision, marked by questions Jordan poses to the universe that don't necessarily have answers. Utilizing allusion as a device, Hemingway plays with this multi-potentiality within the novel's thematic and syntactic context.