In A Separate Peace by John Knowles, why does Gene not mention Finny after Finny's death?

After Finny's funeral in chapter 12, life continues in chapter 13 of A Separate Peace. Gene's class is graduating from Devon and preparing to enter the war effort. Meanwhile, in June, military units move onto the campus to set up sewing machines for the purpose of sewing parachutes together. Brinker and Gene talk about the war and what they are witnessing with great interest. Brinker turns the talk to Leper's failed enlistment and that he would have done better to be stationed here sewing parachutes. Gene feels uncomfortable talking about Leper and says, "Why talk about something you can't do anything about?" (197). This must be Gene's philosophy at this point in his life. He feels powerless to change anything, especially with people over whom he has no control; therefore, why discuss it?

Gene's philosophy seems to carry over to what happened to his best friend, Phineas. He doesn't see any reason to talk about Finny after he's gone because there's nothing more he can do about it. In a way, this is also respectful. Stressing over Finny's death, something that he can't change, allows the memory of his friend to be kept sacred and at peace. Gene elaborates as follows:

"I never talked about Phineas and neither did anyone else; he was, however, present in every moment of every day . . . Finny had a vitality which could not be quenched so suddenly . . . That was why I couldn't say anything or listen to anything about him, because he endured so forcefully that what I had to say would have seemed crazy to anyone else—I could not use the past tense" (202).

For Gene, it seems as though Phineas was bigger than life when he was alive, so talking about him would not do him justice. Only Finny could do himself justice and he is gone now. Furthermore, talking about Finny in the past solidifies the realization that he is gone for good; however, thinking about him in his heart, as though he were always present, keeps his memory going. Gene goes on to say that Phineas taught him how to live in the moment as well. Finny would tackle the present with all the energy of his heart and personality. Gene also realizes that no one else that he ever knew could live in the moment as well as Phineas, so Gene decides to honor him by doing the same.