According to Gene, what else was it that saved Finny and made him different from everyone else? What eventually broke Finny's harmonious spirit?

It is not clear; though Gene has been through a great deal, with his relationship with Finny and Finny's death as well, it seems like he has adopted some of the coping mechanisms that Finny had, and is not as touched by this kind of struggle. For a time, though, Finny's death is the force that floors him; maybe he is not exactly the same after this happens, though Gene tries his best to say that Finny lives in him, so he will get by okay.

But, at the same time, Gene admits that he had broken Finny's "harmonious and natural unity"; if Finny too had lost this, can Gene ever hope to retain it? And what does this mean about Gene? He has given various explanations in the book for hurting Finny‹from it being a blind impulse in him, to it being an attempt to win out over his friend, to the accident being the sole product of some dark side that he has. Are any of these really the truth? Indeed, Gene seems reluctant to speak directly and honestly about the accident, and say definitively what his motivation was and why. And maybe this isn't something Gene will ever know; as he admits in the book, there are a great number of things that he doesn't know about himself, that he would like to never find out.