Twenty-five years ago one of the most popular plays in London mocked a lingering taboo; its title was catchy: No Sex Please - We're British.
Ireland in the 1990s has made some headway on sex; it still fumbles nervously with class.
The joke in the play was that sex lay, if you'll forgive the phrase, at the bottom of all things British in the late 1960s and early 1970s.
The irony here is that class has been at the heart and head of all things Irish for a lot longer, yet we still approach it crab-wise, under cover.
Ask half a dozen people tuppence.
Most, I suspect, would prefer not to discuss it at all. Class is, as sex was, a subject best avoided in polite company.
But, as we are reminded by some quietly authoritative voices - Tim Callan, Brian Nolan and John Walsh of the ESRI, P.J. Drudy and Michael Punch of Trinity - class is the key to an increasingly fragmented society.
Its influence is everywhere. It's most clearly visible in health, education and welfare; in queues for hospital beds and the absence of teachers where they're needed most, in yawning gaps between rich and poor.
But who would deny its presence, too, in law and the administration of justice? In the design and collection of taxes? In access to systems which are theoretically available to all?
The pecking order glimpsed through Brinsley McNamara's squinting windows may have vanished. A new and more rigid order has been established; and you don't have to break any so-called moral code to fall foul of it.
All you have to do is to be old, ill or poor, as Callan, Nolan and Walsh showed in a report published on Tuesday: welfare rates have risen by 16 per cent over the last four Budgets, average household incomes by 22 per cent.
If the Government follows its present policies, devotes significant resources to tax reductions and fails to increase welfare by more than the rate of inflation, the numbers earning less than half the average income will rise.
And P.J. Drudy had a related message when he contributed to a Prime Time discussion on proposed regional divisions on the day after the Irish Farmers' Association had led its members and supporters through Dublin.
Our problems, he said, were not those of geography, as the proponents of new regional divisions argued; they were problems of class.
He and Punch had written in a study published in September: "There is no firm rationale for excluding disadvantaged communities in the Dublin region or elsewhere from either national or EU assistance."
But how are class issues to be tackled by political parties which have always done their best to avoid them, indeed have acted as if they didn't exist and this was a classless society?
The answer, I fear, is that if it's left to parties which claim to represent all classes when it's plain that they don't - and can't - then fragment ation will continue.
And the confusion, frustration and aggression which fragmentation generates will grow outside and apart from a political system which pretends it doesn't exist.
Even in the 1920s and the 1930s this was not a classless society. Those who said it was had chosen to ignore differences between cities, towns and country places.
They pretended, as the Irish Farmers' Association still believes, that it's possible to represent rich and poor farmers as if their interest were identical. Deeper differences between landed and landless simply didn't occur to them.
The landless, like the dispossessed of earlier years, were all but invisible in the 1930s and 1940s: women paid three halfcrowns a week to work from early morning to nightfall; men who slept in farmers' lofts and were known as boys to the end of their days.
The pretence of classlessness served political purposes. It meant the Civil Warriors of Fianna Fail and Fine Gael could claim the only division that mattered was on the national question, which kept them at the centre of things.
It meant Labour must wait. In any event there was a party of the left, called Fianna Fail. It was a claim that should have died with Taca, the fundraisers of the 1960s, but didn't.
For some strange reason, Micheal Martin resurrected it last weekend in the aftermath of Fine Gael's victory in the Cork by-election.
A party of the left in a classless society may have been what some had hoped to see. Now, any mention of either ambition is a reminder of how futile they were in the first place.
The stirring changes of the 1960s brought Taca as well as industry, speculation as well as a building boom, the first deep links between business and politics.
Rhetorical claims and romantic notions have been replaced by uncertain responses to loud and harshly contradictory demands supported by displays of electoral, organisational and financial muscle.
But the most powerful influences on the coalition's decisions may not be visible to the naked eye, as the Taoiseach let slip at last week's meeting of EU heads of government in Austria.
Challenged by the attitude of the new centre-left government in Germany to corporation tax, Mr Ahern insisted that Ireland would resist any demand for change. Part of Ireland's success lay in its low tax rates.
Our corporation taxes are, of course, the lowest in the Community by a long chalk, which may account for the extraordinary levels of growth forecast by the Commission.
But our public services are among the poorest in the Community, which accounts for the problems to which the ESRI drew attention.
The Government isn't even looking for a resolution of this contradiction. When it comes to class interests, its stance is clear.
During last year's election and in the Budget that followed, it was so crudely rightwing that it left John Bruton sounding distinctly social democratic.
Mr Martin's talk about being left of centre is nonsense. Charlie McCreevy uses leftist as a term of abuse. He scoffs at criticism that comes from the left, or what he insults as the poverty industry.
This, I suspect, will prove a less popular view than Mr McCreevy and his friends think it is. Most people are generous in their contributions of time and money to voluntary organisations.
More and more are repelled by the evidence of corner-cutting and sharp practice which seems to be tolerated, if not encouraged, by politicians whose bravado isn't matched either by judgment or performance.
The need to restore confidence in politics is obvious. It can't be done by pretending that everyone's interests are capable of being served at once. Parties will have to make it clear whose interests they serve.