One of my favorite angles of Edward Cullen is what he brings to the concept of nature vs nurture.
Like. He's the classic self-hating broody vampire. Except I don't think Edward truly hates being a vampire. He's actually mostly okay about it before he meets Bella-- at most, he resents aspects of it. We get the sense that he sees all the instinctual stuff as undignified, and both the lived experience and prospect of eternity are dull, if a bit droll.
What Edward truly hates about himself are choices he's made: his Dexter era (and disappointing Carlisle with said Dexter era), dooming Bella's prospects of a 'natural' life, leaving Bella. The fact that he hates his own choices are much more rich than if smeyer had left him at simply hating what he is (struggling with extreme propensity for slaughter), because becoming a vampire was not his choice.
And sure, vampires are rational enough that any murder they commit (purposefully or otherwise) can weigh on them in an interesting way, except that for all the Cullens talk about not wanting to be monsters, Twilight has a very whoopsy-daisy approach to vampires that eat humans. Killing people is not a choice for Twilight vampires. It is the default. The lack of a choice, giving into natural urges results in dead humans. Killing is effortless; resistance is the uphill climb.
Despite this, taking literal pains to abstain from human blood is not seen as some base courtesy in the same vein of humans refraining to hurt each other when our emotions get charged (I really deserve some praise and awe for not beating my coworkers daily!!). No, they are framed as awesome and praiseworthy for their commitment (even though their commitment to preserving human life does not extend to removing their dangerous selves from society altogether). It's something they don't have to do to be considered decent; no one ever bemoans Jasper or Carlisle for having human-eating friends, with the exception of when it endangers Bella. Eating humans is on par with having a mildly cringe political belief in the Twilightverse. "Oh, yeah, my buddy Garrett.... killed more people than my immortal supercomputer brain can count, but otherwise he's cool." Bella thinks the world of the Cullens for their efforts, but in turn she's extremely forgiving of their mistakes. Jasper attacking her is (according to her) her fault for being in his house and full of juicy delicious blood.
So is Edward to resent Carlisle for forcing this nature onto him, or appreciate him for showing him how to deny these instincts and remain a benign actor in the world? Can Edward really attribute the blood on his hands to vampirism when his most ardent dream as a human was to join the Great War? If the war lasted to past 18th birthday and he hadn't died, there's no way of knowing if any blood would have been directly on his hands the way he can count how many people he ate as a vampire. But does that matter? He'd have contributed to a war machine that killed people as impersonally and callously as the average vampire picks their victims. At least vampirism gave him the means to be more deliberate in playing God, no?
But what playing God really his motivation, or was he simply raised to believe that war=glory? It's almost definitely the latter, and he never asked to be raised that way (further complication: his own mother tried to sway him away from enlisting), so how does that stack up to the killer instincts of vampirism?
Basically I love how Edward is semi-aware that he was always doomed to be a killer, yet in the face of the ineffable forces/concepts of nature and nurture, he chooses to believe "actually I just suck as a person". #1 character of all time
