Obviously I don't agree with all of that but it's a reasoned out answer from your point of view. You do, however, prove that social policy cannot be made solely on the basis of "fairness" or else you wouldn't exclude anyone for any reason.
My philosophical interests have, frankly, shifted wildly over the last year or so, which is why modern fuzzy liberal arguments about "fairness" and "equality" (not to be confused with classical liberal arguments on the same topics) aren't generally in my vocabulary any longer. By some definitions, as I've read, that would make me a "conservative," but I'm not a fan of conforming to ideology as it is. And I also have a very strong interest in the philosophy of morality, which I could probably write a book on, of which gay issues would only form a single chapter.
Is it that we now know something that they never learned, or is it the other way around. They knew something we may have forgotten?
To me, this seems like a very romantic view of the past. In reality, most of our ancestors generally lived one day at a time and didn't have a larger perspective beyond the culture they lived in any more than we do now. They made many mistakes, just as we are bound to make them and just as our descendants will make them too. Some will argue that, because we are bound to make mistakes and change our minds, so to say, that it means that "absolute truth" does not exist, and, as an extension, not even try to pursue it. Looking through my past writings here, I know I had argued that repeatedly, but nowadays, I think that that central tenet of postmodernism is wrong. Such ideals as freedom and liberty, for instance, may be modern constructions, but it is hard to argue that both ideals were only "right" in modern times; they would, of course, have been right all along.
From a theological point of view, too, there is the idea of "divine revelation," where new divine truths can be newly revealed in modern times, presumably for reasons only divinely known. Admittedly, of course, such a concept can be tremendously abused, which is probably why it was grounded somewhat with more worldly, rational Aristotelian philosophy in Thomism.
Overall, though, I think we need not fear progress or a departure from tradition necessarily, as long as the arguments are sound. In the case of gay marriage, I believe that the arguments in favor of it are overwhelmingly better constructed than arguments against it, which often are unable to pass an even cursory philosophical examination, due to them often being built on tremendously flimsy assumptions that don't pass logical muster.
As for the inevitable larger questions regarding the state of marriage and the modern family, they are concerns that I share, as well. However, it is my view that tying the decline of marriage and family to gays and gay marriage is overtly fallacious. The gay couples trying to get married are the ones more likely to live conservatively than that of the general population, and most certainly will make far better married couples than the archetypal heterosexual Hollywood "marriages" we see every day. I think those are probably far more influential on the American psyche than gays ever were or could hope to be.
