The McCracken report presents us with two inescapable conclusions: firstly, self-regulation doesn't work; secondly, the investigations which Mr Justice Brian McCracken and his team began must not stop now.
Politicians insisted for decades that they were capable of policing their own affairs. They were wrong. And the claims that those in business or the professions should be left to their own devices were wrong too.
Mr Justice McCracken has demonstrated with clarity and precision how inimical to the public interest the combination of political power, carefully guarded secrecy and financial interests can be.
His report confirms, but does not complete, the exposure and disgrace of Charles Haughey and Michael Lowry. It shows both as untrustworthy, secretive and devious; willing to run risks with public office for private gain and personal grandeur.
But there was an element of chance in their destruction. If Ben Dunne and others in his family had not fallen out, would Mr Lowry's dependence on them have come so suddenly to light?
If, as he reached for power, Michael Lowry hadn't made powerful enemies who could lay hands on such damning information . . . And might it not be said that, in this context, Mr Haughey had been hit by friendly fire?
Regulation which depends on chance is not good enough when the risks are as Mr Justice McCracken describes them:
"It is quite unacceptable that a member of Dail Eireann, and in particular a Cabinet Minister and Taoiseach, should be supported in his personal lifestyle by gifts made to him personally. It is particularly unacceptable that such gifts should emanate from prominent businessmen within the State.
"The possibility that political or financial favours could be sought in return for such gifts, or even be given without being sought, is very high, and if such gifts are permissible, they would inevitably lead in some cases to bribery and corruption."
Regulation which depends on the assurances of recipients or donors that everything is above board is almost as fallible as regulation by chance.
This is why the investigation begun by Mr Justice McCracken must continue. And, despite the assurances of Bertie Ahern and Mary Harney's limp excuses, it should embrace Ray Burke's donation of £30,000 as well as the affairs of Mr Haughey and Mr Lowry.
Some have been saying this week that what Mr Justice McCracken had to report came as no surprise to them. Others, like Joe Lee, asked what, in that case, "the rest of us" were doing.
It's not the first time the question has been raised. And on other occasions the air was thick with excuses: politicians explaining to journalists that they didn't have the evidence to go on; journalists pleading libel to excuse themselves.
But to find evidence you have to make the effort; and party discipline or the libel laws are more effective when they're reinforced by timidity, laziness or a yen for the quiet life.
Foolish notions of loyalty have a lot to do with it, as anyone listening to people in North Tipperary and Dingle must have spotted.
Some crazy notion of tribal loyalty certainly possessed those who attacked Jim Gibbons and others in Leinster House on that night in 1982. Loyalty to a authoritarian leader in the populist mould, who personified the party and the nation.
As Des O'Malley said on Prime Time on Monday: "We lived in very strange times. Very strange things went on for over 20 years."
What happened, as Mr O'Malley and others of all parties knew or suspected, was a bizarre twist of Frank Cluskey's criticism on the day that Mr Haughey became Taoiseach.
Cluskey said Haughey's ambition was not simply to run the State but to own it. Now it's clear that this man, one of the most influential figures of the past 30 years, must have been in thrall to others.
While he responded to questions in public with a mixture of pomposity and condescension and often treated those who worked for him with withering contempt, he was himself obliged to shadowy figures in the background.
Lowry, we know, was owned, lock, stock and barrel, by Dunnes Stores. Who owned Haughey?
Or, as Mr O'Malley asked, who were the donors, what were the circumstances and what were their rewards?
This is not just of concern to Fianna Fail or the members of his governments who still hold office. It's of the highest importance to the people of this State who have watched an unlovely retinue parade before them for decades.
Mr O'Malley agrees with Dick Spring and Pat Rabbitte about the irresistible popular demand for further investigation. John Bruton has won support for the view that Mr Haughey could help by naming his benefactors.
Preliminary investigations may well be needed to prepare the ground for a tribunal whose terms of reference are as precise as Mr Justice McCracken's. The co-operation of the Cayman Islands authorities will be important, perhaps essential, to its work.
These authorities refuse to co-operate with governments or their agents in pursuit of tax dodgers. But more is at stake here: the possibility of political corruption is no longer as farfetched as it once seemed.
In the meantime, other issues remain to be resolved. The Director of Public Prosecutions must decide whether Mr Haughey should be prosecuted; the Revenue Commissioners are no doubt examining the affairs of both men.
Mr Burke remains in charge of Northern affairs at what has been described by Mr Ahern as a historic moment, while his colleagues don't seem sure of what's happening in the Garda investigation of his donation.
Mr Spring asks pointedly about the Revenue Commissioners' apparent inaction in Mr Haughey's case during the years in which the former Taoiseach was so clearly living beyond his means.
And Mr Rabbitte insists that accountants, lawyers and bankers who help hide funds in offshore accounts should not be left to regulate their own affairs.
But politicians who propose or attempt to enforce regulation have been as bitterly derided as Haughey's old opponents in Fianna Fail once were.
Remember the attacks on Eithne Fitzgerald? Dame Eithne, as Alan Dukes called her, echoing the mockery of "Honest Jack" and "Garret the Good" by Haughey's cute hoors.
Some politicians and some journalists were swimming against the tide but "the rest of us", as Joe Lee calls them, weren't listening.
They liked the idea of an inside track. A track with two gauges, the narrow for those who needed or thought they needed help to get what was rightly theirs; the wide for those who paid to get what they wanted.
Inside dealing and insider trading is the inside track writ large.
We heard the voices from the streets - as benign as Ben Dunne, North Tipp had voted for Lowry and North Tipp stood by its man. In Dingle someone wanted to put up a plaque to Haughey.
There was a more poignant voice. Frank Harrison, the waiter who stepped from the crowd to shake Mr Haughey's hand outside Dublin Castle when others booed, was interviewed again by Myles Dungan on the day after McCracken.
Would he shake Mr Haughey's hand now? He wouldn't. Why not? Mr Harrison, it seems, is 78. He works two nights a week to supplement his pension. He pays tax on his earnings. He doesn't feel sorry for someone who does not.
Ten years ago Mr Haughey too said he was against the dodgers: "There will be vigorous penalties for evasion," he promised in an interview with Aspect magazine (February 1987) "If necessary, jail sentences will be used."