For Whom the Bell Tolls' is a novel by Ernest Hemingway that was published in 1940. The title comes from a poem by John Donne which refers to the fact that when one person dies, it affects everyone else as well. The novel tells the story of an American soldier fighting in the Spanish Civil War and the people he meets along the way. The main theme of the novel is the inevitability of death and the importance of living life to the fullest.