How we cite our quotes: All quotations are from Birdman or (The Unexpected Virtue of Ignorance).
Quote #4
MEL, PLAYED BY MIKE: Okay, j-j-just put the gun down Ed. She just doesn't love you anymore.
ED, PLAYED BY RIGGAN: You don't, do you?
TERRI, PLAYED BY LESLEY: No.
ED, PLAYED BY RIGGAN: And you never will?
TERRI, PLAYED BY LESLEY: I'm sorry. ED,
ED, PLAYED BY RIGGAN: I don't exist. I'm not even here. None of this even matters. I don't exist. I don't exist. [Slowly he lifts the gun to his head and, against the protests of Terri and Mel, he shoots himself].
This time it's not just Riggan who's struggling with an existential crisis, it's his character, Ed. We can, of course, compare the two, but it's more interesting to note the differences. What causes Ed to doubt his existence is, like Riggan's, his worth as a human being. But, whereas Riggan's worth is determined by respect and reputation, Ed's worth is determined by love.
Quote #5
SAM: If you weren't afraid, what would you want to do to me?
MIKE: I'd pull your eyes outta your head.
SAM: That's sweet.
MIKE: I'd put 'em in my own skull, and I'd look around so I could see the street the way I used to when I was your age.
This is Mike expressing his desire to redefine his perception, his identity. Normally we think of Riggan as the one dealing with mortality, growing old and losing his relevance. But Mike feels the aging too, and wants to regain the kind of youth that Sam has (while at the same time mocking her for wanting to play a game like a child).
Quote #6
RIGGAN: Stop saying we, there is no we. I'm Riggan f***ing Thomson.
BIRDMAN: No; you're Birdman. Because without me, all that's left is you: a sad, selfish, mediocre actor, grasping at the last vestiges of his career.
Despite what he wants us to believe, Birdman is most definitely a mental formation. He's the part of Riggan's ego telling him that he's not good enough. That he has lost all former glory and success and somehow ended up in a place that "smells like balls." Riggan's need for success outside of the bird costume is manifested in the berating words of Birdman.