Gene's anger and bitterness toward his friend make sense only if Finny is really a lying, manipulating enemy bent on destroying Gene.
And Gene's quest for academic excellence makes sense only as means of showing up Finny.
The freedom exhilarates Gene at times — the first forbidden jump from the tree brings him to a new, heightened awareness of life — but uncertainty nags at him.
Finny's whims disturb Gene's comfortable routine of study and proper behavior, habits of obedience that win the approval of adults.
The revelation of Gene's guilt and his refusal to admit it cause Finny's second fall, the accident that ultimately ends his life.
Only in the friends' last conversation, in the infirmary, can Gene face Finny and freely discuss the fall on Finny's own terms, without rationalization or duplicity.By the end, Gene has suffered and inflicted suffering, and he has grown into an understanding of his own dark motives.He has lost his innocence and has gained experience.A Separate Peace tells the story of Gene's painful but necessary growth into adulthood, a journey of deepening understanding about his responsibility and his place in a wider world.At the beginning of the novel, the young Gene stands unconcerned, self-absorbed, by the tree that will test his true nature.I did not do it, Gene seems to be saying, my knees did it.A fall and a tree sharply recall the story of Eden, the Fall of Man, and with it the end of innocence.Significantly, in describing his actions on the limb, Gene insists not that he bent his knees, but that his knees bent, as if his body were not under his control.Again, Gene takes shelter in a childish, self-centered defense.This "all or nothing" thinking, childish in its simplicity, leads Gene to resent Finny and ultimately causes the violent outbreak that destroys a life.Out of Gene's discomfort arises a dark suspicion: Finny is deliberately drawing Gene away from his studies in order to make him fail. If Gene is trying to obey the rules in order to win approval — the only validation he really recognizes — then anyone who encourages him to disobey, or follow other rules, must wish him harm. In his own defense, Gene hides his resentment and lets his (seemingly justified) anger burn within him while he single-mindedly pursues his goal to become the best student and so show up Finny.