If you really wanna talk about the "underpinnings of human civilization," then I'll point out that same-sex marriages existed in Ancient Rome. It wasn't until Rome became Christian that same-sex marriage was expressly outlawed. So there's that.
we're not in rome, therefore there's no need to do as the romans do. we're in the United States of America, and our legal codes recognize a very specific definition of marriage.
As for a reason to allow same-sex marriage: All people should be treated equally under the law unless there is some good reason not to. And "because that's the way we've always done it" really isn't a good reason to marginalize anyone.
all people
are treated equally under the law. all people, straight or gay, have access to
marriage as our legal codes define it. anyone can marry any one consenting and unrelated adult of the opposite sex they like once they have obtained license to do so. who's being
marginalized here? again, what sort of societal imperative is there for rewriting the rules? how will society as a whole benefit from legalizing gay "marriage"? I'm asking a serious question. it's called a social
contract for a reason; it was arrived at through careful negotiation among the people and if anyone wants to change it, they need to negotiate (through the channels recognized by the letter of the law) to do so.
