I’ve read quite a few slippery slope arguments from the religious right against allowing gay people to marry … but Damon really has discovered a doozy. He notes that a German Ethics Council has come out in support of allowing adult siblings to marry (something that the German government opposes):
The council’s position is based on the claim that “the fundamental right of adult siblings to sexual self-determination” overrides all other moral considerations, including “the abstract idea of protection of the family.” That is very similar to the rationales that have been used to uphold reproductive rights and to strike down bans on same-sex marriage throughout the United States.
Except it isn’t “very similar” to any such arguments. In fact, the argument for gay couples to be able to marry is based precisely on “the abstract idea of protection of the family.” Here’s why: By singling out gay people alone and barring them from the same civil institution that binds their own families together, we are actually attacking the family itself. So the point of gay marriage is the very opposite of the case for incest or polygamy, both of which tear families apart and undermine social order.
And unlike heterosexual adult siblings, gay people have historically been barred from marrying anyone they fall in love with and want to spend their lives with. Siblings can marry anyone they want right now, as long as they’re straight, except their siblings. The case for incestuous marriages is therefore to add another option to an already vast array of choices. The case for gay marriage is to give gay people just one option, like heterosexuals, where before they had none at all.