In A Separate Peace, what has Gene learned about hatred, jealousy, friendship, war?

Through the course of A Separate
Peace, Gene waivers between friendship, jealousy and hatred in analyzing his
relationship with Finny. He learns how quickly deep appreciation of Finny's enthusiasm
for new, different, unexpected activities can change to feelings of apprehension,
discomfort and betrayal. Gene finds himself being protective of Finny and his changed
physical needs at times, but at other times is resentful of the ease with which Finny
overcomes his changed capabilities, the ever-present reminder of Gene's betrayal of
their solidarity. Certainly, the presence of WWII on the world scene impacts the lives
and attitudes of the boys at Devon School, but in another sense, the "war" is within
each individual as he struggles to come to terms with himself and his response to
growing up and facing adulthood under those conditions.