In A Separate Peace, Phineas, an ebullient youth, creates imaginary adventures and games that create an appearance of reckless gaiety and peace amid the reality of the approach of World War II and deep conflicts.
An adventuresome youth, Finny creates daredevil activities and games that entertain friends and himself, providing them the appearance of security as they defeat danger and as he defies the authorities. Narrator Gene Forrester notes that "[A] streak of tolerance was detectable" on the part of the faculty for Finny, who seems to be a student
...who combined a calm ignorance of the rules with a winning urge to be good, who seemed to love the school....[so] the faculty threw up its hands over Phineas and so loosened its grip on all of us.
Gene feels that he and the other boys remind the faculty of "what peace was like, of lives which were not bound up with destruction," and so the faculty members allow the boys to create this appearance of contentment under the threat of war.
Amid this milieu, Finny flourishes and develops more and more the appearance of insouciance and gaiety. Gene admits that he is deceived by his own happiness for "peace is indivisible, and the surrounding world confusion found no reflection inside me."
Later, the Winter Carnival, born of Gene's imagination creates a further discrepancy between the appearance of carefree boyhood in Finny's world of sport and the looming threats of reality. After Phineas places a laurel wreath made of evergreens upon Gene's head, the boys feel
...a liberation from the gray encroachments of 1943, the escape we had concocted, this afternoon of momentary, illusory, special and separate peace.
But, perhaps, the greatest illusion of all is the appearance that Gene gives of being Finny's friend. In the end, after returning to Devon School, Gene comes to the realization that while he has envied Finny, Finny was always his friend and had not ever wanted to cause him to make bad grades or fail in any way, as Gene in his pettiness had believed. Gene knows then that "wars are made...by something ignorant in the human heart." This private evil of Gene's is also the same evil that begins wars. This is the reality.