On September 19th, the day on which the same-sex marriage bill failed in the federal Parliament, Liberal front bencher Cory Bernardi was forced to resign as shadow parliamentary secretary and right-hand man to Tony Abbott after asserting that same-sex marriage could lead to legalised bestiality. That evening Waleed Aly, ABC presenter and host of Radio National, sought to discuss the limits of rational argument on this issue with Dennis Altman, professor of politics at Latrobe University.

This was unusual because, although political journalism often raises philosophical issues, it rarely takes them seriously; but Aly sought to clarify a distinction which seems basic to ordinary, everyday argument viz., the difference between an exception and an inconsistency – he asked Altman how we can justify same-sex marriage as a departure from the norm, but dismiss those who say they want to marry a dog, or more than one person? Is there a rational moral basis to draw this line and if not, why are we so offended by Bernardi’s remark?

Altman began by stressing the need for an ‘element of sense’- common sense tells us that if dogs cannot speak neither can they consent. He did not respond to Aly’s point that the likes and dislikes of pets might be observed, and no mention was made of Peter Singer’s controversial idea that one can infer consent. Nor was reference made to those marriages, common in other cultures, where partners are chosen by families. But it seemed to them a good lawyer’s answer, based on the ‘centrality’ of consent, to rule out bestiality.

But it did not rule out polygamy, which Bernardi had said was another risk if same-sex marriage was legal. At this point the conversation seemed to lose focus. While Aly continued to press for a compelling reason – an ‘element of sense’ – to rule out a ‘three-way marriage’, the discussion moved on to the matrimonial habits of the King of Swaziland, the ‘deeply conservative’ nature of the British Prime Minister’s support for same-sex marriage, the courage of MP’S Kirsten Livermore, Rob Oakeshott and Sid Sidebottom in voting against their own political interests, and the idea of monastery life as a form of group marriage. It was never less than interesting, but there was no serious attempt to pursue Aly’s question.

For many listeners this will be no surprise – there is a popular view that answers to controversial moral issues are, in the last analysis, matters of personal preference, like whether Thai cuisine is better than Vietnamese. On this view moral argument is no more ‘rational’ – in the sense of reasoning from shared standards governing preferences – than dogs barking over a bone. The logic seems obvious: since it is a truism that ‘everyone has their own values’, there can be no shared standards by which to judge such disputes and no means to confirm the right answer. If this is right then Aly’s quest must end pretty much where it begins – as soon as it becomes clear the parties are in fundamental disagreement.

Before considering this larger, sceptical claim it is worth seeing how far conventional argument might go. This calls for clarification because the dispute is not over some ideal concept of marriage, but an institution which has evolved over centuries, and whose legal and other benefits are such that no one seriously seeks to abolish it – the argument is over who should enjoy them. Importantly, the debate assumes that marriage serves a social aim or aims – that it has a point – even if people disagree over what that point is. To justify a complaint that exclusion is unfair we need to clarify this rationale which – since it is an official practice – must make sense for all, not just those who see marriage as a religious sacrament.

That question becomes an inquiry into why the state should still be involved in what was for centuries a private contract based on an exchange of vows followed by cohabitation, and which by the mid-sixteenth century came within the jurisdiction of the Church. But common law marriage had important consequences; it conferred rights and imposed duties – primarily for the husband’s benefit – and settled issues of legitimacy, agency, property and succession. It also transformed a simple contract into a rigid status relationship. The long and painful process of emancipation of women, with suffrage, property rights, entry to the professions, the pill and divorce as a matter of right, has brought a more flexible and balanced relationship.

The question is on what basis can we say the point of this practice (the reason why it has and deserves official status) makes it unfair to discriminate against same-sex couples but not bestiality or a three-way marriage? For a less prejudicial view of the same values of dignity and fairness which underlie the rights of a wife has over time ended much of the discrimination against same-sex unions. In a thoughtful and nuanced essay in the Australian Literary Review of February 2nd, Altman notes the legislative reforms by states and territories in recent decades, and concludes that substantive discrimination has been largely overcome – the debate is now about the symbolic value of marriage not a right to participate in the material benefits it confers.

It is difficult to disagree, but this fact merely changes the focus of argument because, so long as the symbolic role is important, the question of unfair discrimination is relevant. Thus any mature social system will have a practice of honours and awards to recognise major contributions to its common aims – awards for bravery, philanthropy and lives dedicated to public goals are widely celebrated to encourage others, but also to maintain respect for the values they exemplify. No one would dispute that to withhold recognition on grounds of race, religion or sexual orientation must be unfair and indeed insulting.

Wherein, then, lies the symbolic importance of marriage? We cannot say it is in having children and sharing the responsibility for raising them. That might be the aim of most couples who marry and the reason why a religion forbids contraception and morning-after pills. But it cannot explain marriage as an official institution – even those who share this aim do not believe it is the business of the state to impose a duty of procreation. This is why the traditional exchange of vows, as well as the declarations required by law, are silent on the matter. We need a rationale which, as Altman says, has an element of sense – it must fit both the facts and our values.

Rodney Croome, writing in New Matilda for 11th Feb 2013, argues that marriage is important because it serves ‘traditional family values’. Precisely what this means is not clear but if we read it in a way which supports the thesis we might agree that the essence of family values is an ideal of mutual love and support, to the exclusion of competing relationships – sexual, romantic or otherwise. The commitment to this ideal of a loving and mutually supportive union, intended to be permanent, is a good reason to treat marriage as an institution of unique value – something any civilised society has reason to both celebrate and encourage – including by those who choose not to have children or are unable to do so. The phrase ‘family values’ also connotes duties of friendship and care which arise in respect of a spouse’s children, parents etc. If Croome is right it is prima facie unfair to exclude same-sex couples who wish to make the same commitment.

This is the kind of rational moral basis which might be supported by those who choose not to marry, regardless of their sexual orientation, lifestyle or ambitions. They might see this commitment as important for raising a family, or more generally as a prime social value in its own right, as when soldiers and firemen commit to risk their lives for the common good, or someone commits to a duty to care for aged or disabled parents. This is so obvious and natural we might think Croome’s appeal to ‘family’ values lacks ambition, since an unselfish concern for others is clearly a community value and perhaps even a universal value.

This larger rationale would resolve arguments for marriage with more than one partner because this commitment, and the constraints it puts on self-interest, are designed for a shared life governed by a prime responsibility for each other’s wellbeing, which for most people will be incompatible with competing sexual and other intimate relationships. This is why, where openly bigamous marriage flourishes, it is likely to be for doctrinaire reasons, with a risk it serves ulterior aims, as is arguably the case with Mormon families of Joseph Smith’s time. Qur’an scholars, when explaining why Islam allows up to four wives, are surprisingly candid – they simply say the sexual passions of men make fidelity too much of a hardship.

One might also find anthropological reasons – such as a shortage of men due to war – to explain past cultures which have practiced polygamy, but this merely strengthens the argument that, in the absence of such reasons, official recognition is likely to be counter-productive – that it is not something a government has reason to encourage or celebrate. At the same time citizens remain free to devise their own sexual and domestic arrangements – they are free to share vows with more than one partner and have wedding cakes, receptions, Mendelssohn and speeches and live together without breaking the law of the land. The offence of bigamy is constituted by going through a formal solemnisation of marriage while already married and is punished nowadays more as a public nuisance – in the corruption of official records – than as a major crime; it is, of course, a serious offence if one party is deceived.

Denis Altman, while agreeing the issue is symbolic, has no doubt the legal constraints on same-sex marriage should be removed on grounds of equality, and especially to counter a religious view of marriage which promotes homophobia by preaching that homosexuality is against the will of God. In his essay in Australian Literary Review he applauds those who seek reform, and sees those who oppose it as defending a ‘romanticised notion of marriage’ whose meaning has changed fundamentally in recent decades; but he also has reservations, chief of which is the ‘loss of radical critique that was central to the early gay and lesbian movement.’

It is hard not to be sympathetic. A radical critique, one which goes back to first principles to question conventional practice, is important for any society which aspires to live by its ideals. It goes to the heart of JS Mill’s defence of liberty and why we celebrate the Renaissance, Reformation and the Age of Reason, and admire the philosophical traditions of the ancient Greeks; it is why Galileo, Ghandi, Nelson Mandela and Martin Luther King rank high in the pantheon of cultural heroes.

Opposed to this is the conservative world-view, and the kind of moral conservatism preached by Lord Patrick Devlin in his Maccabean Lecture to the British Academy in 1959, in which he argued that society had the right to enforce its moral views, whatever they were, if necessary by the criminal law. His address became a defence of conservative values against reforms proposed in the 1957 Wolfenden Report, which agreed with Mill’s idea that there was an area of private morality which was not the law’s business. It was the subject of a famous debate with the late HLA Hart of Oxford, arguably the most distinguished legal philosopher of his time; it added a chapter to jurisprudence texts and fuelled a transatlantic controversy in law reviews and journals of political philosophy which has never quite ended.

Altman is especially apprehensive of a vicious contemporary brand of American conservatism pushed by the religious and Republican right, which he believes influenced John Howard in 2004 to place gay marriage on the Australian political agenda by changing the definition of marriage to rule out same-sex unions. It is not surprising that his support for legal equality comes with a reminder that the greater danger by far is the exploitation of latent homophobia in the service of a conservative political ideology.

Luke Gahan, writing in New Matilda of Feb. 5th (‘Keep family values out of marriage equality’), likewise supports legal equality but objects strongly to Croome’s attempt to justify same-sex marriage by ‘traditional family values’. Since these reflect heterosexual lifestyles this must, he argues, stigmatize those who are or choose to be different. On its face the argument is persuasive, because a truly liberal society must be neutral on matters of lifestyle and sexual preference. But reflection suggests this dispute turns almost wholly on the meaning of ‘family values’; if, as Gahan supposes, it means ‘heterosexual’ values, it will be discriminatory for society to celebrate and encourage a way of life which excludes gay unions.

If, on the other hand, it means a sincere commitment to love and support each other, it will transcend distinctions based on sexual orientation as much as it does those based on race, religion, social status and wealth. Hence if the essence of marriage is in a loving commitment intended to be permanent, this clearly includes same-sex marriage, but not multiple marriage or ‘marriage’ with an animal. Someone who thinks the only point of marriage is to conceive and raise children will of course disagree and someone who favours ‘open’ marriage may argue that it is, despite the evidence, compatible with such a commitment or that sexual fidelity no longer has value in a modern, consumer world.

In summary, whether it is unfair to exclude non-heterosexual couples and polygamous relationships will depend on the rationale of marriage as a social institution, which is a matter for argument and discussion. But if the most defensible rationale is found in the traditional vows then it can hardly be unfair to exclude casual relationships – those in which parties are unwilling to make a serious commitment – and if this is not unfair there can be no stigma and therefore no cause for complaint.

One can, of course, offer a radical challenge: one could argue that marriage – despite reforms – is an outmoded institution which limits the potential for personal growth and fulfilment. But to make this case it is not enough to argue that marriage is designed for heterosexual families – one must still consider the best interpretation discussed above – the importance of a commitment to the wellbeing of others. In most cases this will call for a domestic regime suited to raising children and caring for dependent family members; but this is merely one possibility since there are childless marriages and many end in divorce – the commitment does not cease to have value if there are no children or because it does not last forever.

Elle Hardy, in New Matilda for April 3rd, 2013, (‘Why is there a law on marriage?’) puts a radical challenge, prompted by concerns over past abuse of the institution – she wants to abolish marriage altogether. The only exception is ‘a need to right the wrongs of eternal discrimination by granting equal rights to all citizens – but only in the short term.’ She concedes that marriage, ‘a nice, albeit expensive, celebration of commitment, which comfortably dissolves into drunkenness and bad dancing – is not a bad thing in and of itself’; but ‘it is important for people to be able to define marriage of their own free will’ in order that ‘the government may have no business with either our hearts or our bedrooms.’

Despite some confusion between marriage and weddings and a somewhat dismissive view of those who continue to value marriage her article might be read, generously, as a reminder of the risk that any culture, supported by leaders as much as the public, can go badly off the rails, and even victims come to believe that the established order is the proper order. This is the danger Mill warned us of; it is also a primary source of dramatic tension, as well as much of the humor, in period pieces such as ‘Downton Abbey’, with its regular confusing of moral values with manners, protocol, social practice and conventions – its confusion of what people think is right with the best interpretation of values they are committed to defend.

This brings us back to an objection briefly raised at the beginning of this paper – the claim that on controversial moral issues there is no scope for ‘rational’ argument because there are no shared standards to govern it. This is, after all, the point of Aly’s question and it seems clear there are no ‘objective’ or ‘absolutist’ criteria which define the purpose of marriage; it is, as suggested, a matter for argument. This fact leads the sceptic to conclude it must be a matter of choice – more like dogs fighting over a bone than we care to admit. Perhaps this is why Altman ignores the question; like Aly he has no idea how to answer it. But this does not lead him to treat his own opinion as merely autographic, a self-revelation we might or might not find interesting; it is meant as a judgment on what is right for all parties.

The assumption here, shared by all who participate in the debate, is that the ‘right’ answer lies in the best explanation of the practice or institution in terms of values we see ourselves as sharing, however abstractly conceived, and in light of our understanding of human nature. Whether this view is ultimately defensible is, as one might expect, a central issue in moral philosophy; but it affirms the aspirational logic taken for granted when we argue from values, that the best interpretation is the one which counts and must be sought in the values themselves, not in opinions, conventions, social practices or institutions which reflect popular views, however distinguished their authors and regardless of the numbers in support.

In recent decades the idea that there can be right answers to controversial issues of social and political morality has been the target of a form of scepticism described by one critic as a fusion of French linguistic theory and German metaphysics. Much of the appeal of this scepticism lies in the promise of an egalitarian theory of moral truth – no one has the right to condemn the moral judgments of others and no community has the right to criticise other cultures. There is no space here to discuss such heady claims, whose influence has been pervasive in the social sciences, other than to suggest they would – among a host of other problems – threaten any meaningful distinction between an excuse and a justification.

However that may be, it is worth looking at forms of argument which cover the same ground and raise similar questions. Legal disputes are similar to but differ from moral argument. The assumption of right answers is fundamental to law, including where there are no clear rules such that courts must reason from legal principles, and judge their relevance and importance when in conflict. The disputes are not different, in the nature of the obligation they impose on judges, to those where ordinary citizens dispute the meaning and importance of shared moral values – the duty is to interpret them consistently with judgments of the same values, past as well as hypothetical, they see themselves as committed to defend.

The differences are obvious: lawyers interpret legal principles against a background of authoritative precedent and in a context which makes the opinion of the court decisive whereas ordinary, everyday moral argument leaves this to the parties. But the integrity of interpretation is tested in the same way, by seeing how well it matches judgments of comparable issues where the same values are in play, and especially those interpretations which best explain practices and institutions whose importance no-one disputes.

Ordinary moral argument rests on community values; we argue from a sense of fairness, and from the importance of freedom, human dignity, community wellbeing, honesty and so on. It differs from religious moral argument by ignoring two questions which are the essence of religious thinking – where do values come from and why are they important. For most people these play no role in social and political debates – the values are there and need no pedigree – the debate is over what they require in disputed cases, and their importance when in conflict. By contrast, moral philosophers often seem more concerned with questions of genesis and authenticity than with real-life issues of war, social justice and unfair discrimination.

Another difference is that most religions, like legal systems, specify some authoritative method – a designated official(s) or sacred text (often both) – to determine what is right for members – and often for non-members – whether this has to do with major issues such as abortion, contraception and suicide or less dramatic questions about eating meat on Fridays or not working on Sundays. This feature, unlike the first, has consequences for social and political debate because it commits members to doctrinal answers, without regard to values. Politicians who think contraception is against the will of God will find it difficult to respond to interpretations of dignity and autonomy taken for granted in other areas of social life.

In conclusion, the fact that arguments on issues such as same-sex marriage persist does not show there cannot, in principle, be a right or best answer – in terms of being more consistent with our shared values (on political matters especially values of humanity which argue for fairness, freedom, compassion and human dignity) than competing answers; it merely reminds us there is no agreed means to demonstrate or verify such a claim. But if this is the case there is no reason to suppose we ever reach the limits of reason – that we ever reach a point where we must give up the interpretive exercise and look for another way.

It is time to summarise. This paper began with a question about the limits of rational argument on issues like same-sex marriage. It argues that whether it is unfair to exclude non-heterosexual couples and group marriage must depend on the rationale of marriage as a social institution. It finds this in the vows invoked in traditional ceremonies and implicit in formal declarations under the Marriage Act, which most people see as central to the idea of ‘family’ values.

A second aim is to highlight the difference between moral values and widely held opinions on moral issues. So long as this distinction makes sense the answer to Waleed Aly’s question is simple: there are no limits to moral reasoning. If, on the other hand, our values are compromised by equating them with what we value, anyone is free to dismiss opinions simply because he does not like them; in which case no debate can begin. It means argument on controversial moral issues must be irrational and even offensive.

Finally – to anticipate a natural response – democratic theory offers no help because the opinions and preferences of a majority are not values, hence cannot serve as standards. Misunderstanding arises from the fact that, because we value institutions which serve our interests, it is easy to confuse a popular view that marriage is important with the values which justify society encouraging it. We are then at risk of treating a moral consensus as if it were a moral reason, when the only question is whether it accords with our values.

That question leaves us free to affirm or condemn any consensus; it means society can live by its ideals, always responsive to a better interpretation.

*Pic: The Marriage of the Arnolfinis, Jan van Eyck, 1434

Max Atkinson is a former teacher at the University of Tasmania Law School with interests in legal theory and and international law.