In A Separate Peace, what does the nature of friendship reveal about true virtue?
Knowles uses the characters of Gene and Finny specifically to demonstrate that true friendship illuminates one's character (virtue or lack of it). Finny sincerely believes that Gene is his friend and has good intentions toward Gene. Finny's friendship with Gene reveals that Finny is an enthusiastic, optimistic, compassionate person. For example, he knows that Gene is an outsider at Devon, and yet he befriends Gene and champions him to all the other boys. Finny has nothing personally to gain from a relationship with Gene; so his willingness to build up Gene shows that he is virtuous. Similarly, Finny encourages Leper when he does not perform in athletic activities as well as the other boys and points out positive aspects of Leper's personality--again, Finny has nothing to gain from his treatment of Leper and acts as he does simply because that is his nature.
In contrast, Gene's friendship with Finny reveals his insecurity and bleak view of himself. He is skeptical about Finny's motives and allows his jealousy to cause him to injure Finny. While Gene's character does not involve cruelty, his friendship with Finny does allow readers to identify Gene's willingness to harm others in order to build himself up.