Does gay marriage prove marriage matters?

Just over a century ago, the Anglo-French writer, Hilaire Belloc, declared himself "opposed to women voting as men vote. I call it immoral, because I think the bringing of one's women, one's mothers and sisters and wives into the political arena, disturbs the relations between the sexes."

The idea that extending the franchise to women would do serious and irreparable damage to the social fabric is a useful reminder that views once widely held can soon seem absurd. Today, anyone in a western democracy who attacked the place of women in politics would not be taken seriously.

Yet we should also recall that it was to be many years before women enjoyed the same political rights as men. But views did change and as resistance was overcome, society changed too. So who's to say the same thing won't happen with marriage?

Last week, the Tasmanian House of Assembly became the first in Australia to come out in support of gay marriage. The historic vote was passed with the support of both Labor and the Greens.

Tasmanian Greens leader, Nick McKim, has pledged to push for the legalization of same-sex marriage in the Apple Isle if the Federal government does not act "in a timely way".

Now pressure is building on the Gillard government to take note. In Canberra, the Greens are determined to introduce same-sex marriage in the current Parliament.

Their goal is to enshrine equality for gay and lesbian people in legislation. Since the Australian people are much more conservative than the so-called 'inner-city elites' often realize, the Greens are likely to face a big political challenge.

Nevertheless, the Greens' commitment to same-sex marriage has already accomplished something significant, though they probably don't realize this.

By promoting same-sex marriage, the Greens have obviously moved the debate about the nature of marriage closer to the top of the political agenda. This is just how progressive ideas considered 'crazy' in one generation become commonplace in the next.

However, the Greens have also unintentionally kick-started a larger conservative debate about the health of the institution of marriage.

The first aspect is well-understood. The second tends to be completely overlooked.

In order for gay marriage to become uncontroversial, we would first have to agree on what marriage actually is. This is the fault-line dividing marriage traditionalists and advocates of gay rights. Yet that kind of agreement seems some way off.

Those with a conservative point of view believe that marriage is the union of a man and woman which provides the social, biological and moral context for raising children. In other words, gender matters in marriage.

Proponents of gay marriage, on the other hand, say gender no longer matters in marriage. What matters today is the right of two people who love each other to live together in civil equality before the law. In other words, marriage is about equality.

This standard aspect of the debate is basically about gender versus equality. And if the Katter brothers are anything to go by, just about every man and woman in Australia has a view on the topic.

What is interesting though is that suddenly marriage seems to matter again. Ironically, the gay marriage campaign has brought 'traditionalist' concerns about the health of the institution of marriage into a sharper focus.

Not a moment too soon.

Marriage has been steadily going out of fashion in Australia since the late 1970s. Over the last two decades or so, Australians have tended to marry less and divorce more.

According to figures from the Australian Bureau of Statistics, when a couple gets married (whether in a religious or civil ceremony), the probability that the marriage will end in divorce has increased from around 28% twenty years ago to around 33% today.

At the same time marriages now last longer before divorce comes. In 1988 you could expect to be married for 10.1 years before the split. By 2007 this had extended to 12.5 years.

Whatever way you look at it, the prospects for any new, first marriage are not great. Perhaps that helps to explain why nearly 30% of Australians never marry in the first place.

What is surprising, therefore, is that supporters of gay marriage now tell us that more people actually want to get married. The very institution widely dismissed as irrelevant ("It's just a piece of paper!") and roundly mocked is now top of the 'must-have' list for a significant minority of the Australian people.

It's as if we are suddenly seeing a surge in demand for a brand of car known to have a 33% chance of breaking down and leaving you by the side of the road.

The Australian people have yet to decide whether they are ready to stretch the meaning of marriage to embrace a new social creed and different family types.

Yet thanks largely to the Greens, it is increasingly clear that the concept of marriage still has qualities that touch the lives and hopes of people deeply.