The novel's primary theme is concisely expressed in the John Donne passage which provides the title and the epigraph:
No man is an Island, intire of it selfe; every man is a peece of the Continent, a part of the maine; if Clod bee washed away by the Sea, Europe is the lesse . . . any mans death diminishes me, because I am involved in Mankinde; And therefore never send to know for whom the bell tolls; It tolls for thee.
Examined closely, this epigraph suggests all of the major themes: the centrality of the Spanish tragedy to European and world history, and as a testing ground for World War II, the necessity of commitment, involvement in the struggle, the fundamental oneness of humanity, and the urgency of love.
Looked at in another light, the central theme turns on the recognition that neither political parties nor struggle in their cause may replace the individual quest for significance through self-knowledge and love. If one perceives the world of the novel through Robert Jordan's eyes, this quest for wholeness occupies center stage and the theme is resolved in his love, his oneness with Maria, together with his sacrifice, his dying knowledge that "the world is a fine place and worth the fighting for."
Another view holds that Jordan's quest, love, and sacrifice as well as his politics are rather muddled and secondary to the true focus of the work: Spain itself as the hero, the people,...
(The entire section is 271 words.)