Bad arguments about same-sex marriage have a bad habit: they keep coming back. I'd like to take a look at one particular repeat offender. The short version is that
by definition marriage
is between a man and a woman, and so recognizing same-sex marriage would be confusion. The argument comes in two versions, and I'll say something about both, but it's worth noticing that even people who favor civil unions offer some variation of this argument as a reason for not supporting same-sex marriage.
The first version is the crude one. The idea is that the meaning of the word "marriage" covers opposite- sex but not same-sex unions. ("Look it up!" you might hear.) The trouble is that the meanings of words aren't carved into reality. Words mean what we mean by them; what we mean can and does change. Even supposing that at the moment "marriage" means a union between a woman and a man, all this would show is that
at the moment, most people use the word that way.
As it happens, however, if you like the "by definition" argument, the dictionaries aren't as clearly with you as you might think. Here's the first definition from the online version of Merriam-Webster:
...the state of being united to a person of the opposite sex as husband or wife in a consensual and contractual relationship recognized by law
But right on its heels, we find this one:
"the state of being united to a person of the same sex in a relationship like that of a traditional marriage"
Dictionaries don't dictate meaning; they record usage. What Merriam-Webster tells us is that usage is changing. People who describe same-sex unions as marriages aren't confused about the meanings of words, but people who argue against same-sex marriage on lexicographic grounds
are confused about what "meaning" means.
This brings us to version two - the sophisticated version. It doesn't depend on dictionaries; it agrees that we could use the
word marriage in any way we choose. What's at stake on this version of the argument is something about reality - "definition" in the sense of
essence.
An artificial example might help. We use the word "water" to pick out a particular kind of substance - a substance with a real nature, or so many people say. We could decide to use the
word "water" to refer to any clear, drinkable liquid. However, even if we
called vodka "water," vodka and water are very different substances and the difference isn't a matter of convention; it's in the nature of the things themselves. (Not everyone will go along with the idea of things having real natures, but as we'll see, allowing the point won't do any harm.) Furthermore, there are laws on the books about water (about levels of contamination, for example, and about water rights) and in applying those laws it would be disastrously crazy to ignore the difference between the substance we now call "water" and other substances we might decide to apply the word to.
Some people argue that the same point applies to marriage. We could use the
word marriage in any way we liked, but there's a certain real kind of relationship picked out by the word "marriage" as it has been used traditionally. That reality, so the argument goes, is very different from same-sex relationships.
An extended version of this argument turns up in a paper called "What is Marriage?" by Girgis, George and Anderson (GGA). (Harvard Journal of Law and Public Policy, Vol. 34, No. 1, pp. 245-287, Winter 2010.) You can read it here:
http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1722155
According to GGA,
marriage is not a legal construct with totally malleable contours—not “just a contract.” Otherwise, how could the law get marriage wrong? Rather, some sexual relationships are instances of a distinctive kind of relationship—call it real marriage— that has its own value and structure, whether the state recognizes it or not, and is not changed by laws based on a false conception of it. Like the relationship between parents and their children, or between the parties to an ordinary promise, real marriages are moral realities.
A bit later, they add:
...the state cannot choose or change the essence of real marriage; so in radically reinventing legal marriage, the state would obscure a moral reality
As for what this reality is, GGA argue that reproduction is at its core. The claim isn't that marriages must produce children to be real marriages, but what partly creates and "seals" a marriage is an act (sexual intercourse) that by its nature is associated with reproduction. GGA argue that marriages can still be
marriages even if the couple is infertile, or even if the couple deliberately avoids reproducing. Readers can decide for themselves on how well GGA handle this issue, but I want to set it aside; my point is a different one.
Suppose that there is a real, non-conventional relationship between individuals with pretty much the character that GGA emphasize. Let's suppose that this relationship has a nature or essence every bit as real as the nature or essence of water. Even if this is true, it doesn't tell us whether there should be a legal institution of marriage that extends to same-sex partners. Interestingly, GGA give us the clue to seeing why. The crucial sentence is this one:
Like the relationship between parents and their children, or between the parties to an ordinary promise, real marriages are moral realities.
Insofar as I understand the notion of a moral reality I agree that parenthood and promises count. But consider parenthood. I have two children. They're my biological children, and that's not a matter of convention. However, my relationship with my children isn't just biological. I hope I'm their parent in a fuller sense than that, even if biology is where the relationship got its start. So let's agree: between me and my children there's a relationship that GGA might call "real parenthood". But suppose someone tried to argue from the biological and moral reality of this kind of relationship to the conclusion that the law shouldn't recognize adoptive parenthood. That would be a howlingly bad argument.
In the sense of "real" that GGA have in mind, adoptive parenthood isn't "real parenthood." But the fact that the law allows adoption and treats adoptive parenthood on a par with the biology-based kind is a very good thing. There's no "obscuring of a moral reality" here. There's a broadening of a legal/social institution for good reasons.
Promising is a different kind of case. Let's grant that when I make a promise, that creates a moral reality: I come to have an obligation to the person I made the promise to. Obviously, however, the "moral reality" of promising depends on conventions. That doesn't make the obligation less real, but it makes the point that human conventions can give rise to moral realities. Second, which cases of promising fall under the
law can't be settled by looking at the moral realities. There are promises the law doesn't enforce, and there are promises that meet the letter of the law even though we might think that if it weren't for the law, they wouldn't count.
This bears on same-sex marriage in two ways. First, even if same-sex unions aren't "real" in the metaphysical way that GGA have in mind, this doesn't answer the question of whether the law should recognize them. Second, even if same-sex marriage depends on adopting new conventions, that doesn't rule out there being a moral reality that goes with it.
Here conservatives raise a worry. Without a clear account of marriage really is, the argument goes, we're on a slippery slope to including incestuous "marriages" and polygamous unions. However, if that's your worry, appealing to the meaning of the word "marriage" or the nature of marriage won't help. Polygamous unions have been around for a very long time. There's no linguistic confusion in saying that Solomon had many wives. If you're worried about polygamy, appealing to the meaning of the word "marriage" won't help. As for the "nature" or "essence" of marriage, it's completely unclear that GGA or anyone else can show that polygamous marriages are a relevantly different kind of beast from two-person marriages. If you don't want polygamy recognized, you set yourself a very hard task if you try to rule it out on metaphysical grounds.
So are we on a slippery slope? Not at all and precisely
because the law isn't about language or metaphysics. Legal marriage is a human-made institution. What its boundaries are doesn't depend on what conjugal relationships "really" are, and doesn't depend on what falls under the dictionary definition of "marriage." It's a virtue of the law that in making laws, we can appeal to pragmatic and policy reasons. If there are good policy reasons for ruling out marriages with more than two partners, we can do that whatever the metaphysics. The same goes for the case of consanguinity. We don't need to plumb the depths of marriage's essence to decide where we want to draw those kinds of lines.
Notice, in fact: for all I've said, there might be excellent policy reasons for
not recognizing same-sex marriage. If there were, that could be reason enough not to recognize them; no need to rifle dictionaries or worry about essences and natures. My view is that the case is very much in favor of same-sex marriage, but that's another post. The point here is that worrying about what "marriage" really means or what marriage really is "essentially" doesn't get us anywhere. It doesn't even help conservatives make their own case.