Gene Forrester is a character whose worst enemy is himself. Although he is a capable athlete and an excellent student, Forrester is unable to prevent the dark side of his inner self from perverting and distorting his enjoyment of the world and the people around him. As Forrester admits to himself in chapter 7, he always finds something bad in the things around him; or, if he does not find it, he invents it. This proclivity, clearly the product of a subconscious force, results in paranoia. At one point in the novel, Forrester entertains the absurd idea that Finny is deliberately trying to destroy his scholastic success (even though Finny is obviously unconcerned). Forrester’s personal insecurity is such that it drives him toward somehow getting even with Finny, which he eventually does by causing Finny’s fall from the tree. Even though Finny’s accident and subsequent death liberate Forrester from his dark interior impulses, something vital inside him also dies.
Finny may symbolize the kind of person Forrester wishes he could be; Finny is an almost complete opposite of Forrester, a natural athlete and a complete individualist, interested in immediate and innocuous personal pleasures. Against the confining background of the Devon School strictures, Finny constructs his own world out of his imagination: It is Finny who invents new games to play; it is Finny’s idea to jump from the tree into the river. Whereas Forrester is all calculation, Finny is all spontaneity. Like Forrester, Finny represents an extreme. Forrester’s eccentricity is built on his inability to cope with his dark subconscious mind; Finny’s way of dealing with the world is geared toward completely ignoring unpleasant realities of any kind. At the end of A Separate Peace, Finny is forced to confront a world he cannot physically dominate or imaginatively reshape. Thus, he flees from Hadley’s trial of Forrester, refusing to deal with Hadley’s emphasis on facts; similarly, he refuses (for as long as possible) to acknowledge Forrester’s deliberate injury to him. Dealing with such realities seems to break Finny’s will at the novel’s end, which may be one reason that he dies during his second operation.
The other characters in the novel are simple foils to Forrester and Finny, although both Brinker Hadley and Leper Lepellier represent two other ways of coping with oneself and the external world. Hadley is a walking personification of a conservative, law-abiding mentality. He monitors the order at Devon School and always does things logically: For example, when the Devon term is over, he will enlist because that is the correct path of action. For a time, during Finny’s absence, Forrester aligns himself with Hadley’s way of acting. Significantly, however, when Finny reappears at Devon, Forrester immediately gravitates toward his old friend and all the complex things that Finny represents to him.
Leper Lepellier is an even less influential character, whose dominating personal characteristic is a romantic form of eccentricity. A passive creature, Leper derives his pleasures through such pursuits as snail collecting, sketching outdoor scenes, or awakening in the place where the sun first shines on the continental United States. At Devon, Leper’s urge is to become a part of the quiet, natural world around him. Then, when the war fervor changes the nature of the outside world, Leper is the first to enlist. He pays a significant price for his impulsive brand of romanticism; at boot camp, he suffers a nervous breakdown from which he does not fully recover in the novel. Still, it is Leper who forces the boys at Devon to acknowledge the harsh realities awaiting them outside the walls of the Devon School.