I'll say first off I think this is for the most part an absolutely fantastic game with a great story, but one thing bothers me and i'm wondering if anyone else feels the same way. So through the reveals of there being an infinite number of alternate worlds, and Comstock basically being an alternate Booker, it felt kinda... cop-outty to me. Not in the sense that it's lazy or something, but just that now so many of the questions as to the nature of Columbia, how it came to be and Comstock's motivations can't be answered, or can just be left to "things probably happened in an alternate reality". I feel like there's a ton of stuff I can never know or understand about the events of the game, because of this very easy hand-wave of "alternate reality things happened". Basically what i'm saying is to an extent, it seems like the story is tied too closely to the nonsense science of the world, or at least the latter part. Too much about Columbia and the tears can't really ever be made sense of.

The way I read into Comstock's motives was that after Booker's baptism, and taking the new identity of Comstock he became somewhat of a religious zealot. He set about creating this "utopia" of Columbia with the ultimate goal of attacking the world below as he believed them to be sinful, of course he learns that he will die before he can put his plan into motion, so he needs an heir. He talks about meeting the Arch Angel in audio logs, so he believes he's following a higher order.

The problem there is how the hell did he jump from "religious zealot" to "creator of a new society in the clouds, complete with incredible futuristic technology". It seems like the answer is cyclical; he had those means because in an alternate future he'd already found them. That's my issue.

@lackingsaint

Yeah, I see what you mean. The city was built using the technology of the Lutece "twins", but how Booker/Comstock convinced them to build it (and fund it) I have no idea, that might be left up to alternate realities I suppose.