Rather than leave them buried in the comments, I thought I would respond to two very good objections to my prior post on same-sex marriage as a new post, especially because I think they are worth preserving as part of the libertarian conversation on the same-sex marriage issue.   Both objections are raised in one form or another by Joshua Herring.

1.  Doesn’t the “equality before the law” argument run into trouble if we think of a different analogy?  Take the fact that, historically, the US has only subjected men to the military draft.  Does my earlier argument imply that libertarians must support extending the draft to women in the name of equality before the law.

When I first posted my original argument on Facebook awhile back, I had already thought of this objection and Joshua’s version of it allowed me to develop my response more fully.  I will simply cut and paste from the comments on the earlier post:

The draft involves the state actively coercing people.  To argue that the state should (also) coerce (to be more realistic) women into a military draft is to argue for equality before the law in a way that ALSO tramples on the other libertarian principle – the right of the individual to not be coerced.  Legalizing SSM extends a state-provided benefit to a group equally situated (consistent with equality before the law) but does so without any additional coercion (everyone already pays the tax) and thereby violating the other key principle.   (Kevin V’s point about anti-discrimination laws noted.)

In other words, legalizing SSM meets the requirements of one of the two principles without compromising the other.  Drafting women meets the equality principle but only by more strongly violating the rights principle.  Thus legalizing SSM seems much more obviously libertarian than does extending the draft to women.

As Joshua agrees that this point distinguishes the cases, I’ll say no more.

2.  His second objection is more subtle.  He wants to argue that the move to recognize SSM at the federal level is, for some people, only part of the battle, which is really to open up marriage to, for example, polyandrous polygamous  [See note below] groups.  Joshua nicely tinkers with my analogy to make this point:

What if the proposal was to extend Social Security benefits to blacks only, but not to Asians.  This is meant to analogize extending marriage benefits to gays, but not to everyone else who could reasonably use them.  This is the reason I am not enthusiastic about federal recognition of same-sex marriage.  “Not enthusiastic” means that I don’t mind if they get extended to gays, but I’m not explicitly in favor of the cause until it’s really about equal rights for everyone.  Just as, I imagine, an Asian in your counterfactual world could only be so happy about seeing Social Security benefits expanded to include blacks.  You know, it might be a sign that they were eventually coming to Asians too, but it still seems unfair, etc.  And of course it’s especially galling if blacks in general are not inclined to fight for Asian SS benefits, and even more so if some black leaders have made it expressly clear that they do NOT favor extending SS benefits to Asians (as several gay rights leaders have said about extending marriage benefits beyond same-sex and heterosexual couples).

My first response is that if Joshua’s analogy more accurately represents the move to legalize SSM, it does create some new problems for my argument.  In fact, it forces me to either “bite hard on the reductio” or be open to the charge of being “bigoted” against the polygamists.   I like arguments that hoist the original argument by its own petard!

So how to respond? I will bite hard on the reductio.  I don’t think there is in principle a libertarian case against legalizing polygamous marriages in a regime where the state defines marriage.  However:

a.  I don’t imagine that under any institutional arrangement for marriage, whether state-granted or not, we would see anything more than a tiny fraction of marriages being polygamous.  We know from history that marriages of n>2 do not seem to have the staying power of n=2.  I do not think this has anything to do with the law, but rather the nature of human relationships.  Simply put, n=2 is a lot easier to coordinate than n>2.  Think in terms of the economics of the theory of the firm:  sure n>2 allows a marriage to divide up labor and perhaps take advantage of economies of scale, just as a large firm can, but the coordination costs escalate rapidly.  With n=2, there’s one relationship to make work.  With n=3 there’s 3 and with n=4 there’s 6.  With n=5 there’s 24.  In general, the formula is (n-1)! .[Correct formula is the summation of i from i=1 to i=n-1 as Jeffrey Johnson notes in the comments]. So I don’t have too many worries about legalizing such relationships as I simply don’t see them as functional in any but the most exceptional cases, and especially not in a well-developed, highly complex society.

b.  I’m actually comfortable in distinguishing SSM from polygamy at the current moment in time because I think that to argue for the notion of “equally situated” that underlies equality before the law requires that the culture see the relevant actors as, in fact, “equally situated.”  Put differently, there’s a reason that SSM is the issue on the table and not polygamy:  it’s because, culturally, we have come to recognize the “equal situation” of two men or two women who love each other and want to make a public commitment to their relationship to the situation of a man and a woman who do.  Our common cultural understanding of marriage and of marriage as a dyad based on love is what enables us to make a claim of injustice that we should remedy.  When the polygamy can persuade enough people that they too are “similarly situated” that the issue raises to the level of attention that SSM has, then legalizing it will have sufficient legitimacy to actually work.

As a practical matter, what the relevant “equality” is will be determined by common understandings of what the relevant criteria are.  Right now, it seems to me, that exists for SSM but not polygamy.  There is, in my view, a significant enough difference in our cultural understanding of SSM and polygamy to see the former as “similarly situated” and not the latter.  Will this eventually change?  Perhaps.  When it does, then the case for equality before the law will be in full force and we can have this same discussion over again about polygamy!

Final note:  I’m not sure argument b is a principled libertarian argument.  It is, however, an argument for why we don’t need to worry about slippery slope arguments from those opposed to SSM (“we can distinguish them”) and an argument in response to those in favor of legalizing SSM and much more for why it’s not unjust to make the case only for SSM  (“polygamy doesn’t have the cultural legitimacy of being similarly situated to demand equal treatment [yet]”).

I look forward to reaction to all of this.

[UPDATE:  all references to polyandry are now polygamy and likewise for the other forms of the word.]