I don't even know how to begin to answer this. You talk about logical arguments, McMurphy. I haven't ever heard an argument against gay marriage that I think is logical. But my threshold for logic may not be someone else's.
Honestly, almost the only arguments against gay marriage that I can recall hearing are the religious ones. I consider that those arguments include the supposedly secular argument that redifining marriage would be detrimental to the culture, being that I've only heard it from those who consider the culture to be specifically Judeo-Christian in nature. I won't even go into those arguments here because everyone has heard them, and my critique of them might offend someone. Best not to go there at all.
The only non-religious argument I can ever recall hearing at all, and it not very often, is an economic one - that it would put too much of a burden on business to have to extend benefits to partners in gay marriages as well as to those in traditional marriages. That argument, of course, was also extended to civil unions. Personally, I don't buy that one, either. It's just another way of trying to get out of paying benefits, which many corporations are trying to do just generally.
Oh, wait...there is one other argument that I've heard. I'd class is as religious in nature, in a general sort of way, but I'll mention it anyway. This argument goes that marriage is for the sole purpose of procreation - having babies. Since two men or two women can't have babies, at least not in the traditional way, with the baby genetically related to both partners, so this argument goes, that means that gay marriage is not a legitimate form of marriage. The huge problem with that argument, as I see it, is that taken to it's logical conclusion, it would prohibit marriage also to straight couples who are either unable or unwilling to have children. Since that isn't going to happen, at least at a secular level, I don't think that argument is valid. Although I do remember reading about a couple a few years ago who was denied marriage by the Catholic Church because one of the parnters was either sterile or physically unable to engage in any act that would result in pregnancy in the woman (I can't remember which was the case). Which is why I consider this argument to be essentially religious in nature.
This whole subject just really frustrates me, since the people who want to prohibit gay marriage are, in general (at least among those I know out here in the real world), the same people who tend to walk around talking about how government needs to get out of people's private lives. Since government regulation of who can and can't get married is one of the most private parts of life, it just reeks of government interference in people's lives. So basically those folks are trying to have it both ways.
I'll stop now. I feel a full-scale rant coming on, and it wouldn't be pretty.
