Recently in Australia, many have concluded that the "no" campaign is infected with this pathology. Conservative politicians and Christian officials are not entitled to comment on the importance of matrimony or the safety of children, it is said, because their private or public conduct harms couples or minors. In other words, they lack what we call moral authority.

I have sympathy for this argument, but the idea of moral authority is not as obvious as it seems. To be clear, my interest here is not in the broader status of the church or political parties. No doubt both have diminished in esteem or trustworthiness. But I am concerned here with the very specific loss of trust suffered by those in the "no" campaign. This has less to do with secularisation, disenchantment or fractured party interests, and more to do with egregious transgressions like infidelity, abuse or state-sponsored torture.

To begin, it's important to distinguish honesty from accuracy. No doubt plenty of public officials and institutional figureheads are vicious – just like moral philosophers. They deceive others and often delude themselves. But this does not necessarily mean that their ethical arguments are wrong. If Aristotle was a coward in battle, this would change little about his description of courage. It would simply mean he was unable or unwilling to live up to the standards he described in his Nicomachean Ethics and elsewhere.

Likewise, the philandering politician may be right about the special status of heterosexual marriage but weak, selfish and perhaps just stupid themselves. They would be privately compromised but publicly accurate.

And yet there is something galling about hypocrisy. We have a feeling that someone is no longer deserving of credence; that they lack ethical force. This is exactly what the idea of moral authority describes: not someone who is necessarily right, but someone worth listening to. It is an ethos of recognition, not truth.

But what sort of authority is this? Certainly not the power to think on our behalf. Delegating ethics to others is itself an ethical failing; a refusal to take responsibility for living a moral life. In other words, ethics includes thinking about ethics, not simply inheriting dispositions or mores.

Instead, moral authority is better understood, at least in its modern sense, as a sign of seriousness; of commitment to ethical life. We listen to someone with integrity, not because they give us foolproof answers but because we know they are genuine about the debate itself. They care enough about the issue to conduct themselves conscientiously. Despite their many blind spots or fumblings, they demonstrate goodwill.

The loss of moral authority, in this light, is not an automatic loss of facts or logic. It is a loss of social standing. Specifically, those identified as hypocrites suddenly seem cynical. They do not really care about the issues they purport to champion. They are game-players, realpolitik agents, paid performers. (The word "hypocrite" comes from the classical Greek for "actor".) They may have all kinds of knowledge at their disposal – but it seems empty, because their commitment to the conversation is bent.

So the charges against some "no" campaigners have some merit. It is not that they are wrong about same-sex marriage – they are, for the record – but that they are not worth listening to. Rather than simply being well-intentioned but ignorant, they are revealed as jaded partisans trying to manipulate opinion, or simply egoists jostling for advantage. They are not part of the moral conversation, because they are not really interested in morality. They want to police others, but not themselves.

No doubt this argument works for anyone in the political matrix. The left, taken broadly, is not magically outside hypocrisy – witness Labor's position on asylum-seekers.

But right now, those claiming some enduring tradition of righteousness have a special stake in preserving an image of goodness – and many are failing. Not because they lack the right public relations consultants, but because they lack virtues. They may be successful careerists in politics, religion, or whatever lobbyist territory they have marked. As ethical agents, they are fiends or bunglers.

In short, many prominent figures in the "no" campaign have kept their platforms but not their word. This is why even generous opponents have stopped listening.

Damon Young is a philosopher and author. damonyoung.com.au