I have a question from a member of the studio audience:
I'm a naturalist and I could not answer this objection to gay marriage. I think that marriage was a social construct, but he argued that since I believe that I can't confidently define marriage one way as anyone could define it. And if I can't define marriage I am not able to say there is any specific rights for it. Now, I still believe it to be a social construct, as that is obvious in itself. But how can I define it if it is one? How is my definition any more right than his?
Definitions do not matter in any sense that is relevant here.
Every definition within a language - without exception - gets its meaning as a product of social convention. There is no way to defend any definition of any term as 'the correct definition'. The only thing you can do is argue whether a particular definition fits the way that people generally use the term.
This is true of 'marriage'. It is also true of 'god', 'atom', 'planet', 'malaria', and 'social construct'.
It is very common, and very much a mistake, to take what is true of language and claim it is true of what the word refers to (if anything). There is no 'correct' definition of 'planet' - only the definition that a group of people decide to adopt. This does not imply that those huge rocks and gas balls flying through space are radically changing their properties each time astronomers change their definitions. Definitions concern what we are going to call things. It does not determine what they are.
Philosophers call this the use-mention distinction. There is a difference between using a term the way some group of people have decided to use it, and talking about (mentioning) the term itself. Planets are big balls of rock or gas (or both) flying through space. 'Planet' is a six letter word starting with the letter 'p'. Many of the things that are true of ‘planet’ are not true of planets, and many things that are true of the word ‘planet’ are not true of planets.
Often, philosophers show the distinction (as I did above) by putting inverted commas around a term when it is mentioned, but not when it is used. So, we can write, there is a difference between planet and 'planet', and a corresponding difference between marriage and 'marriage'.
Any talk of definitions is talk about the mention of a term, not its use. We can talk about the definition of 'marriage', or we can talk about marriage. Let us talk about marriage for a bit.
Marriage, as an institution, is a social invention. This means that it is a tool - like knives, computers, and cars – something that humans designed and built because it serves particular goals. We can tell how good or bad a tool is by determining how efficiently it accomplishes the goals that were our reason for inventing it. A bread knife is a knife invented for the purpose of slicing bread. A good bread knife cuts bread cleanly without tearing and is large enough to cut a whole slice at a time.
With respect to knives, it turns out that knives are useful for a lot of things. A knife useful for slicing bread is not so useful for spreading jelly. It works, but a different design will work better. It’s also not useful for skinning a dear or for cutting tile. Slightly different designs are best for those purposes. The result is that we end up with a lot of different types of knives that serve a lot of different purposes.
It would be absurd for anybody to argue that the slicing of bread is the only legitimate use for a knife and that nobody shall be permitted to use a knife (or to invent a type of knife) that serves any purpose other than the slicing of bread.
One could argue that knives are tools invented by humans to serve human purposes. However, this fact cannot in any way call into question the fact that different types of knives serve different human purposes, and that a knife well designed for one purpose may not fit the other purposes people might have for knives.
Now, so somebody might say that the term 'knife' is still limited to that which has a blade. You wouldn't call a hammer a 'knife' because it lacks those qualities that knives have.
This is true. At the same time, I have never heard anybody try to argue that the government should take a position opposed to the invention and use of hammers because they fail to meet the strict literal definition of 'knife'. That type of argument does not even make sense.
The institution of marriage, like the knife, is a tool that humans invented to serve human purposes. The type of marriage that works well for one use might not work as well elsewhere. In this case, it makes sense to design new tools that work elsewhere.
We can then argue whether ‘marriage’ is between a man and a woman the way a ‘knife’ has an edge. We can debate whether the relationship between ‘gay marriage’ and ‘marriage’ is the same as that between ‘butter knife’ and ‘knife’ or if it is more like the difference between ‘hammer’ and ‘knife’. Yet, absolutely nothing that we say in this debate is relevant to the question of whether gay marriage is a useful tool or whether it out to be permitted or prohibited?
More importantly, that debate is already over. ‘Gay marriage’ is already a part of our language. You can use the term in any number of places and people know what you mean. Pointing to an example of same-sex marriage and saying, “That is a kind of marriage” is a lot more like pointing at a butter knife and saying ‘that is a type of knife’ then like pointing to a hammer and saying ‘that is a kind of knife.’
So, the institution of marriage is a tool like every other tool. How good of a tool it is depends on how well it serves the interests of those who would use it. The design of this tool as it currently exists can be improved by making design changes that will serve the interests of homosexual couples.
Of course, many who are opposed to gay marriage will argue that the interests served by gay marriage are not legitimate interests. However, that is a different debate. It is not a debate that one can win (or lose) by noting the fact that all definitions are, in a sense, arbitrary or that the institution of marriage is a human invention where the quality of the design can be determined by the human interests it fulfills.