The author John Knowles, like his narrator Gene, was from the south (West Virginia, to be exact), and sent off to an uppercrust boarding school in New England for polish before university. However, unlike Gene, Knowles was no academic whiz at boarding school; he came close to flunking out of school, and was never the genius student that Gene is portrayed as being.
The novel A Separate Peace is a largely autobiographical work, drawing on Knowles' experience at Exeter to create the Devon school. Like Gene, Knowles attended a summer session at school to make up some classes; however, the year was 1943, not 1942, as it is in his novel. Other than that, the summer session that Knowles describes in the book was very much akin to the summer session that he attended at Exeter. "We really did have a club whose members jumped from the branch of a very high tree into the river as initiation," Knowles has said of his book: "the only elements in A Separate Peace which were not in that summer were anger, envy, violence, and hatred." In Knowles' far more benign summer, "There was only friendship, athleticism, and loyalty." But the atmosphere at Exeter was similar to what he describes for Devon; they both share an old, ivy-covered campus, with great beautiful trees, and the same New England weather. The summers at Exeter and the fictional Devon were also similar in their carefree atmosphere, their warm, summery beauty, and in the amount of enjoyment the handful of students took from these summers.
Phineas, like Gene, also had a real counterpart; Knowles based the character on David Hackett, who was actually a student at a different school, Milton Academy. However, David was at Exeter for the summer session on which the novel is based, and was a founding member of the Super Suicide Society of the Summer Session, which was a real club, and very much like the one described in the novel. David and Knowles were not roommates, but lived across the hall, and became very close as the session progressed. David was a good friend of Bobby Kennedy, and later held a position with Bobby in the Justice department. Whether Gene's jealousy of and competitiveness with Finny was also based on the relationship on David Hackett and John Knowles is unknown, though Mr. Knowles, through his own description of the summer session on which his book is based, would seem to defuse any such theory.
Knowles has admitted that "it is true that I put part of myself into all four main characters in A Separate Peace: Phineas, Gene, Leper, and Brinker." Brinker, like Phineas and Gene, had a real-life source in Gore Vidal, who was a top-notch student at Exeter during the time that Knowles was a student. Although he and Gore were not close friends during their time at school, Knowles does believe in retrospect that he did a good job in distilling the essence of who he believed Gore Vidal to be, into the character of Brinker. Leper has no particular model according to Knowles, but is an amalgamation of a certain type of person whom he runs across repeatedly.
The tragedy of Finny's death was modeled on the death of Bob Tait, a student at Exeter who died in the same manner, on the operating table and as a result of bone marrow escaping into the blood-stream. Knowles was saddened by these events as a senior at the school, and knew Tait to be a kind and gentle person, much as Finny is in the book.
The war had as much of an impact on Exeter life as it did at Devon; Knowles has discussed, as Gene does in the book, how teachers were drawn away from the school by the war effort, and how the students began doing a great many things "for the war." Knowles, like Gene, also had to suffer through the ordeal of crowded, late trains to get back to school. Unlike Gene, however, Knowles was a decently good athlete, participating mostly in swimming; he never achieved the superhuman feats that Finny attains in the novel, but he was no slouch either.
Although the book is mostly based on real events from Knowles' life, still remember that this book is not a work of non-fiction. Knowles himself says that the characters, even those that he bases on real people, are a hodgepodge of different traits and qualities, and many of the dramatic conflicts of the book are not based upon real events, but were invented for the sake of the story. The inspiration and the fuel for Knowles' book was taken directly from his own life experience, but this does not mean that it is solely Knowles' experience that makes up the meat of the events of the book.