The key events in the formation of Jake’s character occur long before the novel’s action begins. As a soldier in World War I, Jake is wounded. Although he does not say so directly, there are numerous moments in the novel when he implies that, as a result of his injury, he has lost the ability to have sex. Jake’s narration is characterized by subtlety and implication. He prefers to hint at things rather than state them outright, especially when they concern the war or his injury. Early in the novel, for example one must read the text very closely to grasp the true nature of Jake’s wound; it is only later, when Jake goes fishing with Bill, that he speaks more openly about his impotence.

Jake’s physical malady has profound psychological consequences. He seems quite insecure about his masculinity. The fact that Brett, the love of his life, refuses to enter into a relationship with him compounds this problem. Jake, with typical subtlety, suggests that she does not want to because it would mean giving up sexual intercourse. Jake’s hostility toward Robert Cohn is perhaps rooted in his own feelings of inadequacy. In many ways, Jake is a typical member of what poet Gertrude Stein called the “lost generation,” the generation of men and women whose experiences in World War I undermined their belief in justice, morality, manhood, and love. Without these ideals to rely on, the Lost Generation lived an aimless, immoral existence, devoid of true emotion and characterized by casual interpersonal cruelty. Part of Jake’s character represents the Lost Generation and its unfortunate position: he wanders through Paris, going from bar to bar and drinking heavily at each, his life filled with purposeless debauchery. He demonstrates the capacity to be extremely cruel, especially toward Cohn. His insecurities about his masculinity are typical of the anxieties that many members of the Lost Generation felt.

Yet, in some important ways, Jake differs from those around him. He seems aware of the fruitlessness of the Lost Generation’s way of life. He tells Cohn in Chapter II: “You can’t get away from yourself by moving from one place to another.” Moreover, he recognizes the frequent cruelty of the behavior in which he and his friends engage. Most important, perhaps, he acknowledges, if only indirectly, the pain that his war injury and his unrequited love for Brett cause him. However, though Jake does perceive the problems in his life, he seems either unwilling or unable to remedy them. Though he understands the dilemma of the Lost Generation, he remains trapped within it.

Brett is a strong, largely independent woman. She exerts great power over the men around her, as her beauty and charisma seem to charm everyone she meets. Moreover, she refuses to commit to any one man, preferring ultimate independence. However, her independence does not make her happy. She frequently complains to Jake about how miserable she is—her life, she claims, is aimless and unsatisfying. Her wandering from relationship to relationship parallels Jake and his friends’ wandering from bar to bar. Although she will not commit to any one man, she seems uncomfortable being by herself. As Jake remarks, “She can’t go anywhere alone.”

Indeed, there are several misogynist strains in Hemingway’s representation of Brett. For instance, she disrupts relationships between men with her very presence. It seems that, in Hemingway’s view, a liberated woman is necessarily a corrupting, dangerous force for men. Brett represents a threat to Pedro Romero and his career—she believes that her own strength and independence will eventually spoil Romero’s strength and independence. Because she does not conform to traditional feminine behavior, she is a danger to him.

As with Jake and his male friends, World War I seems to have played an essential part in the formation of Brett’s character. During the war, Brett’s true love died of dysentery. Her subsequent aimlessness, especially with regard to men, can be interpreted as a futile, subconscious search for this original love. Brett’s personal search is perhaps symbolic of the entire Lost Generation’s search for the shattered prewar values of love and romance.

Cohn has spent his entire life feeling like an outsider because he is Jewish. While at Princeton, he took up boxing to combat his feelings of shyness and inferiority. Although his confidence has grown with his literary success, his anxiety about being different or considered not good enough persists. These feelings of otherness and inadequacy may explain his irrational attachment to Brett—he is so terrified of rejection that, when it happens, he refuses to accept it.

The individuals with whom Cohn travels to Spain only compound his insecurities. Not only is he the only Jew among them, but he is also the only nonveteran. Jake and his friends seize on these differences and take out their own personal insecurities on Cohn. It is important to note that Cohn’s behavior toward Brett is ultimately not very different from that of most of the men in the novel. They all want to possess her in ways that she resists. But Cohn’s attempts to win Brett are so clumsy and foolish that they provide an easy target for mockery.

Cohn adheres to an outdated, prewar value system of honor and romance. He fights only within the confines of the gym until his rage and frustration make him lash out at Romero and Jake. He plays hard at tennis, but if he loses he accepts defeat gracefully. Furthermore, he cannot believe that his affair with Brett has no emotional value. Hence, he acts as a foil for Jake and the other veterans in the novel; unlike them, he holds onto traditional values and beliefs, likely because he never experienced World War I firsthand.

Sadly, Cohn’s value system has no place in the postwar world, and Cohn cannot sustain it. His tearful request that Romero shake his hand after Cohn has beaten him up is an absurd attempt to restore the validity of an antiquated code of conduct. His flight from Pamplona is symbolic of the failure of traditional values in the postwar world.