By ABC's Jonathan Green

Photo: Barry O'Farrell's departure was by all appearances and accounts an honourable response to an inadvertent mistruth (AAP: Dan Himbrechts)

When it comes to the personal conduct of politicians, a slip of the truth is a hanging offence, yet in the public performance of politics, lies are almost expected, writes Jonathan Green.

And then Barry O'Farrell quits for not telling the truth. Innocently of course.

Tony Abbott put his finger on something when he commented, looking very much the prime ministerial version of a stunned mullet, on O'Farrell's sudden departure yesterday: "This is an honour and an integrity at a very high level. We are seeing an act of integrity, an act of honour, the like of which we have rarely seen in Australian politics. I admire him tremendously for this, although I deeply regret the necessity for it ..."

And he's right, politics is not the natural home of high-minded probity. It is a business built on daily deception, on a constant pea and thimble shuffle with the truth.

O'Farrell's departure - by all appearances and accounts an honourable response to an inadvertent mistruth - is also a gleaming example of the profound hypocrisy of our public life, of the gap between private probity and public mendacity.

When it comes to the personal conduct of politicians, a slip of the truth is a hanging offence, no quarter given. In the public performance of politics, a lie is a commonplace, an almost expected behaviour, the mundane reality of our perpetually deceitful public life.

The clear and fatal principle of O'Farrell's departure points to this disconnection, between the lies politicians tell us for a living - the lies we elect them for, the promises they make - and the lies we can't forgive. It's a gap we just don't question, but a gap that nonetheless makes the O'Farrell moment seem somehow bizarre and otherworldly.

Switch perspective and consider the relevance of sincere truth in the political day to day. Here we readily accept the gap between rhetoric and reality, between the actual intention and those slivers of real intention our politicians dare to declare publicly.

We expect them to keep their cards close to their chest, or to shuffle the deck entirely if that seems either opportune or advantageous.

Look at the promises made by the campaigning politician ... there will never ever be a GST ... there will be no carbon tax under a government I lead ... No cuts to education, no cuts to health, no change to pensions, no change to the GST and no cuts to the ABC or SBS.

It's not so much the affront of being lied to, it's more the condescending infantilisation behind the lie, the assumption that we can't handle either the truth or the sober facts of what that truth might imply for policy.

We won't change the age pension ... until such time as the necessities of the budgetary position ensure that we have little choice but to change the age pension. There will be no carbon tax ... until such time as the necessities of forming a workable ruling coalition dictate that there will, in fact, be a carbon tax.

Back to Tony Abbott in the shadow of O'Farrell:

The important thing today is to show proper appreciation of the integrity that has caused him to act in this way. As I said, it will be a long, long time since anyone in Australian public life has acted by this standard of honour and integrity and as I said, I honour him for it.

Honour presumably mixed with a sense of wonder.

If politics wanted to restore its sense of honour and decent service, if it wanted to raise itself in our collective estimation, then it might bring a little of the O'Farrell ethic to its day-to-day.

It might make truth its constant rather than its rare exception. It might share its secrets and earn our respect.

Jonathan Green hosts Sunday Extra on Radio National and is the former editor of The Drum. View his full profile here.

You don't need ICAC to see the lies in politics - The Drum (Australian Broadcasting Corporation)