The novel can be interpreted as an allegory in which Gene and Finny both play significant roles. As they move through their final year at Devon, knowing that the awful realities of World War II await them, their journey becomes an extended metaphor for the loss of innocence. From the summer of 1942 until the spring of 1943, Gene and Finny experience one emotional shock after another and struggle in their own ways to survive them. By the conclusion of the novel, Finny has been forced to face Gene's betrayal and Gene has come to understand his role in Finny's destruction; Finny dies and Gene goes to war: Innocence is lost.
The novel as allegory is further supported by the other characters, especially Brinker and Leper. The boys of Devon become a metaphor for the entire generation of American young men who had to grow up too quickly to meet the demands of World War II. In the novel's conclusion, Gene's mature understanding of what causes war, "something ignorant in the human heart," moves the allegory into the realm of universal truth.
Within the allegory, Finny acts as the symbol of innocence. Of all the characters, only he is not given a last name, suggesting his symbolic significance in the story. In Finny's grace, joy, kindness, humor, love, and unrealistic optimism, he symbolizes the best qualities of being young and as yet untouched by the adult world. Since he does not survive in the novel, his death becomes symbolic of the death of youthful innocence itself.