The title comes from a poem written by John Donne . This novel's epigraph also comes from this Donne poem, so you should check out our discussion on "What's Up With the Epigraph?" But before you do that, can you get anything out of the title?
Well, think about a "bell tolling." Church bells would ring all the time in 17th century England (when Donne was writing) to herald many different occasions: weddings, festivals, or just to announce your everyday church service. But when one speaks of bells "tolling," it usually means one thing: someone has died.
This is a book with death on the mind. It's about a war, and people die in wars. But it's also a meditation on death. Because of the war situation, all of the characters face their own death, and the possibility of having to inflict death on those they are fighting against, or fighting with.
The protagonist Robert Jordan is constantly thinking about his own death: will he die for his cause? Should he die for his cause, or might his happiness and his love be too important? What's death all about anyway?
Beyond that, the characters often ponder and discuss what it means to be responsible for the death of others: is it ever right to kill? How about to kill indirectly by ordering others to kill, or ordering them to their own deaths? If it's not right, what does it mean to be in a war? On the other hand, might it be right, even pleasurable, to kill? Pretty heavy stuff. You might say the bell never stops tolling in this book.
But the title is also asking a question of sorts: it makes you wonder for whom the bell is actually tolling. If you want to answer that literally – i.e., who dies? – you'll have to read the book. Or you could turn to John Donne (and our discussion of the epigraph) for a deeper answer…
Oh, and P.S. – the original title Hemingway had planned was The Undiscovered Country. How might that apply to the book?