The Sun Also Rises (1926), A Farewell to Arms (1929), For Whom the Bell Tolls (1940), and The Old Man and The Sea (1952) are Hemingway's best novels. The Sun Also Rises is the first novel to depict American expatriates' life in Paris in the 1920s. The novel combines disillusionment with traditional values with a new hedonistic attitude, and epitomizes a generation by portraying the anguish of the Western world over the European war, over the shattered illusion of peaceful order that had been irrevocably lost. A Farewell to Arms , with its perfect blend of subject and methods, the tightly knitted themes of war and romance, is often considered Hemingway's most artistic work. Similarly, its themes manifest the destruction and despair pervading Europe and America during and after the war, and demonstrates the emotional condition of the lost generation—"the inception of their psychological trauma, the beginning of their disillusionment and cynicism, the end of their faith in religion and convention as guides to fulfillment ."

In For Whom the Bell Tolls , the longest and most ambitious work, Hemingway strove to weave grand themes of nature, technology, and the unity of mankind. His truer, deeper preoccupations were still with the solitary man proving his mettle and facing death alone. It is a great novel, humane, vivid, intensely memorable, yet it does serve for a larger idea—the protection of a democratic country against the forces of Fascism. If The Sun Also Rises is a novel of youth, and For Whom the Bell Tolls a novel of middle age, then The Old Man and the Sea is a novel of experience gained over the years. The Old Man and the Sea "is a story of skill, of all kinds of courage, of defeat in the flesh, of victory in the spirit, of pride humbled and self-respect earned, of suffering, and of final great peace of mind."