To keep silent about this amazing happening deepened this shock for me. It made Finny seem too unusual for—not friendship, but too unusual for rivalry. And there were few relationships among us at Devon not based on rivalry (3.63).
This may have something to do with Gene's desire to become Phineas. Since he cannot compete with the boy, he doesn't know any other way to relate to him. He can't exist in relation to Finny, so he becomes one with Finny.
"I just fell," his eyes were vaguely on my face, "something jiggled and I fell over. I remember I turned around and looked at you, it was like I had all the time in the world. I thought I could reach out and get hold of you."
I flinched violently away from him. "To drag me down too!" (5.25-6).
As their identities continue to mesh, Gene begins to identify elements of himself – and not such nice elements, at that – in Phineas.
I spent as much time as I could alone in our room, trying to empty my mind of every thought, to forget where I was, even who I was. […] I decided to put on his clothes. […]
This gave me such intense relief […]. I would never stumble through the confusions of my own character again (5.4-5).
Gene loses his guilt because he abandons his identity, at least momentarily, by "becoming" Phineas.
"Listen you maimed son-of-a-b****…"
I hit him hard across the face. I didn't know why for an instant; it was almost as though I were maimed. Then the realization that there was someone who was flashed over me (6.46-7).
Gene again steps out of his own character and assumes Finny's identity, as a crippled (and defensive) guy.
"You've been pretty lazy all along, haven't you?"
"Yes, I guess I have been."
"You didn't even know anything about yourself."
"I don't guess I did, in a way" (8.131-4).
Notice that, in order to learn more about himself, Gene has had to become like Finny – by becoming an athlete.
His eyes were furious now too, glaring blindly at me. "What do you know about it, anyway?" None of this could have been said by the Leper of the beaver dam (9.31).
Gene can only deal with Leper's madness by stripping him of his identity.
"On the limb!" Leper's annoyed, this-is-obvious tone would discount what he said in their minds; they would know that he had never been like this before, that he had changed and was not responsible (11.182).
Think about this idea of responsibility – Leper isn't responsible because he has changed. For Gene, who began his narrative as a "changed" man, this is an appealing correlation.
This touched an interesting point Phineas had been turning over in his mind for a long time. […] "It's very funny," he said, "but ever since then I've had a feeling that the tree did it by itself. It's an impression I've had. Almost as though the tree shook me out by itself" (11.138).
If Gene has no identity, as he later believes when wandering the campus as a "ghost," then this is, in an odd way, true. Gene wasn't Gene when he shook the branch.
I did not cry then or ever about Finny. I did not cry even when I stood watching him being lowered into his family's strait-laced burial ground outside of Boston. I could not escape a feeling that this was my own funeral, and you do not cry in that case (12.70).
If Gene did in some way become a part of Phineas, then part of Finny lives on in Gene. The narrator alludes to this when he says that he still lives his life in Finny's created "atmosphere."
My aid alone had never seemed to him in the category of help. The reason for this occurred to me as the procession moved slowly across the brilliant foyer to the doors; Phineas had thought of me as an extension of himself (12.7).
We know why Gene is interested in abandoning his identity and assimilating that of Phineas (that would be the gut-wrenching guilt), but why is Phineas interested in turning Gene into a version of himself?