As previously noted, I think it's as important as how "marriage" is defined in the dictionary to the subject of gay marriage. Ie: Not very. I notice that metaphor hasn't interested you much in your replies.
I ignored this last night because it didn't strike me as anything beyond a distraction from the main argument. But, since said argument is largely played out anyway and a completely unrelated train of thought this morning brought me back to this, I'll spend a second on it.
(1) The opposite of marriage isn't gay marriage. The opposite of marriage would be divorce or single. Including homosexual unions into the sphere of marriage isn't the same thing. It's the same basic non-argument as the "midget"/"little people" thing. In fact, in addition to "married" or "single", we have words for transitory states between the two: separated, engaged, etc.
(2) "You are if you just say you are" is, in fact, the same exact logic Gbaji has used to try to prevent homosexuals from marrying. "We don't need to legalize SSM, you're married if you just say you are and no government can change that!". It ignores the obvious: the working definition of marriage assumes acknowledgement by the state. Likewise, "you're a girl if you just say you're a girl" sounds more like the rationale of someone trying to deprive
a transgender person of benefits ("You don't need tax-payer funded hormone therapy; you're a girl if you just SAY you are!") than the rationale of someone trying to actually build an argument to include transgender people into their preferred gender.
Now you could have a couple people who say "We DO think we're married because we said we are, so there!" That's fine and I wouldn't waste much energy trying to convince them otherwise. But I also wouldn't defend them when they failed to gain access to things "legitimately" married people gain access to. In the same vein, I'd be much more inclined to argue for protections for someone who has taken steps towards conformity with their preferred gender (medically and/or legally) than someone who simply states "I'm a man because I said I'm a man" and expects that to pass as reason to use the men's room. Or, less flippantly, reason to demand access to a single-gender organization, marry someone of the opposite gender, apply for a scholarship or some other gender-exclusive thing. Late Edit:
Again, the point of my linking to the dictionaries was not to say "they can't be a girl because here's the definition of girl", it was because someone else
made the erroneous claim that the "standard definition of girl" included anyone who just considered themselves a girl. It does not and the quickest way to call out that error was via example of standard definitions. Edited, Mar 17th 2013 5:37pm by Jophiel