I don't, I don't, I don't: why same-sex marriage does not necessarily lead to legalized polygamy

Michael Coren has many virtues that I find admirable: he is intelligent, articulate, and--given his religious convictions--surprisingly independent in his thinking. Despite this he sometimes takes bizarre positions. Take, for example, his call to nuke Iran in 2006. One shakes one's head.

A few days ago, he again went a bit astray in a column that revisited same-sex marriage and argued that the decision will inevitably lead to the legalization of polygamy. Coren provided a convenient summary for his case:

And thus the inevitable. I predict that polygamy will be legal and accepted in this country within five years. Any Charter challenge in support of the custom would not only be backed by the revolutionary precedent of same-sex marriage redefinition but also by guaranteed freedom of religion clauses.

Coren's position has a superficial logic to it: if the rules can change for one group, they can for another, and at first glance the polygamists have two avenues by which they might make their argument: freedom to marry and freedom of religion.

But constitutional law is not a vending machine into which a coin is inserted, thereby guaranteeing a tasty snack. Nor do judges overthrow existing law on a whim. Any future change will require a test-case and a legal argument.

Such was the case with the constitutional challenge that led to marriage equality. The principle at question was the equal protection of the law: that if the state issues marriage licenses, it is unconstitutional to disallow someone a marriage license because she is a lesbian, just as it would be to disallow it for a Chinese, an octogenarian, or a Catholic. Not everyone likes the argument or is persuaded by it -- but the court was convinced, parliament ultimately agreed, and the matter was legally settled, if not politically.

How would this principle apply to polygamy? Essentially, the state limits the number of marriage licenses to one per customer. Do you want to marry someone else? First, your first marriage must be dissolved. At the moment the law is applied to all equally--Catholics, Muslims, Mormons, and atheists are all allowed only to have one spouse at a time. So, too, gays and lesbians. A polygamist can no more acquire a second wife under this principle than he could could have more than one SIN number. There is no avenue for a constitutional challenge here -- at least that I can see.

Coren supposes that the charter principle of freedom of religion might also be invoked. This is less than obvious, however. Freedom of religion prevents the state requiring someone to perform an action that their religion forbids, or forbidding someone from doing something that their religion requires.

As far as I know, however, polygamy is not, a requirement of any religion. Mormonism abandoned it long ago, and although conservative Islam allows men to take up to four wives, it does not require it and never has. (In fact, it is relatively rare even in those countries where it is legal, and Islam doesn't even encourage it: see here and here).

Now, even a superficial consideration of our legal system and various religions' moral systems shows that they operate in different registers. There are many behaviours that religions forbid but the state allows (consumption of alcohol, blood transfusions, divorce); there are behaviours that the state forbids or regulates that religions are silent about (speed limits, the structure of legal trusts, the filing deadline of one's taxes).

In light of this, a successful constitutional challenge to legalize polygamy seems unlikely to me -- there is no obvious legal avenue for a challenge. So, unlike Coren, I doubt whether multiple "I do"s are in any of our futures.