So...wait...you're going to argue that the "why" of marriage is based on a premise that is guaranteed of truth? You do understand that your earlier implication that you are using a deductive argument is utterly ridiculous right? Well, I'll say it again, your premise is highly dubious. You can label that definition as who, what, where, how, why, or huh for all I care. It's not any less dubious to claim that procreation is the sole, undisputed reason for marriage and has been across time and cultures. At the very face of it, a claim that broad and that definitive is going to take an extremely thorough explanation of proof. So prove it. A definition is not proof. And in case you try and circumvent backing up your claims, I'll bust your deductive nonsense with all I have to: Romans had same sex marriage. So it has not "always" been this way. (This is, of course, only one of MANY arguments that easily debunk your premise) I'd also argue that marriage was used as a way of gaining political power. Or of gaining financial advantages. Of course procreation has been PART of why marriage has existed, but the central, "principled" reason of it? That's just ridiculous. But by all means. I only need one counter example. I already gave it. Your premise is now in doubt. Ball is in your court. Unless of course you want to jargon-filled rant by Keyes, in which case, please elaborate. We don't live then. We live now. Family law creates obligations to progeny. Not marriage laws. You're utterly and completely wrong. The rest of this was an intentional sidetrack/tangent to divert from how completely erroneous your claim was. I don't even know what that means. I didn't have to check "I truly love her" on my marriage license. Here's a piece of advice - if you can't speak your point clearly, you come off as deliberately obfuscating. This question is completely unclear. As for your second point, I'd rather call all marriages a "civil union". It's a much more accurate definition regardless of the sexes being married.