How we cite our quotes: In consultation with my editor, we decided (against standard practice) to go with page numbers—since The Sunset Limited is one long act and it would be unwieldy and impractical to number all the lines.
Quote #1
BLACK: So you seen your birthday was comin up and that seemed like the right day.
WHITE: Who knows? Maybe birthdays are dangerous. Like Christmas. Ornaments hanging from the trees, wreaths from the doors, and bodies from the steampipes all over America. (6)
If someone is depressed and isolated, it's especially easy to feel even more depressed and isolated when it's a holiday. There's also a certain symmetry involved: White wants to make his birthday his death day.
Quote #2
BLACK: They could be out there. Maybe they's some other drugproof terminal commuters out there that could be your friends.
WHITE: Terminal commuters?
BLACK: Got a nice sound to it, doesn't it? (85)
If you're a "terminal commuter," you're getting ready for a commute that's headed toward a final end from which there's no coming back, in this case, death.
Quote #3
BLACK: But they might be one commuter waitin there on the edge of that platform that for him it's somethin else. It might even be the edge of the world. The edge of the universe. He's starin' at the end of all tomorrows and he's drawin' a shade over ever yesterday that ever was. (87)
All the other commuters are just going to normal, everyday places—think: work, breakfast, school—but the "terminal commuter" is headed for his or her great leap in the dark, voyaging into whatever awaits him or her in eternity.
Quote #4
WHITE: Well, I've always gone my own way. Ich kann nicht anders. (109)
White's quoting Martin Luther, who said, "Here I stand. I can do nothing else." White means that he's run out of options intellectually—he can do nothing besides protesting life by embracing death.
Quote #5
BLACK: […] Meanwhile, bloodspattered spectators at the hundred and fifty-fifth street station—continued on page four—[…] who were interviewed at the scene all reported that the man's last words as he hurtled toward the oncomin commuter train were: I am right. (114)
Black pretends to read White's obituary in the paper (or the obituary of someone like him). He's implying that White's suicide is over his own intellectual rightness or sense of fairness, that he wants to prove his disdain for the world correct by killing himself.
Quote #6
BLACK: The light is all around you, cept you dont see nothing but shadow. And the shadow is you. You the one makin it. (118)
According to Black, White's ego is the thing that makes the world seem so horrible—it's the shadow cast over everything—so if he could just get that out of the way, he might be able to let a little light in.
Quote #7
WHITE: […] The truth is that the forms I see have been slowly emptied out. They no longer have any content. They are shapes only. A train, a wall, a world. Or a man. A thing dangling in senseless articulation in a howling void. No meaning to its life. Its words. Why would I seek the company of such a thing? Why? (139)
In the depths of his isolation, White has started to see the world as genuinely meaningless. In a way, it's a little like the way Bartleby the Scrivener sees the world in the Melville story of that title. To Bartleby, the world appears to be like a giant opaque wall, with no meaningful markings or any signage posted on it—life is completely devoid of purpose and endlessly obscure.