Credibility deficit has deepened in the Dáil
In the world of spin in which Sinn Féin leader Gerry Adams has long been king, ambiguity is a currency that never fluctuates.
Facts were always deemed inferior to interpretations. In the decades of the Troubles, roaming through the foothills of fantasy, and concealing inconvenient truths in the undergrowth, what mattered most was control of the message at all times. This often meant filtering it through a bank of black fog.
So when Mr Adams stood up in the Dáil yesterday, having been put under pressure by both Taoiseach Enda Kenny and Fianna Fáil leader Micheál Martin to address anomalies in his version of events surrounding the provision of a list of names to the Garda Commissioner, few were teed up for a moment of illuminating catharsis.
Mr Adams performed the usual Sinn Féin soft-shoe shuffle when it comes to putting distance between understanding and doubt.
The challenge for Mr Adams was to explain the inconsistencies between his version of where the names came from of those whom had information about the shooting of prison officer Brian Stack in March 1983, and the version of the victim's son, Austin. Mr Stack has strenuously denied furnishing Mr Adams with the names.
The Sinn Féin leader denounced the murder as wrong, and as a grievous loss for his family - but he insisted that he was given the names by Mr Stack, despite renewed denials by the victim's son. However, the ground fell away beneath his feet in his quest to clarify matters, when instead of answering questions he began asking them: "Why on earth would I say I received the names from him if I didn't?" he asked. He also pointed out that as Austin Stack had given the names to Mr Martin, why would he not also have given them to him?
Once again the difficulty for Mr Adams is that Mr Stack has taken several opportunities to make it abundantly clear that he did not hand a list of names to the Sinn Féin leader.
But matters took an explosive and unprecedented turn when Fine Gael TD Alan Farrell took advantage of Dáil privilege to insist that it was appropriate that two other individuals whose names were in the public domain - Sinn Féin TDs Dessie Ellis and Martin Ferris - should be given the opportunity to address the House.
Mr Ellis immediately interjected helpfully, to explain that he was actually in jail for the period in question, and before that had been in America.
Mr Ferris said that while he met gardaí in 2013 about the death of Mr Stack, he co-operated fully with them and had nothing to answer.
At the end of what were astonishing exchanges we are still not a whole lot wiser. Each attempt by Mr Adams to set the record straight has done anything but.
Last night Austin Stack said his initial reaction to Mr Adams's account was that the Dáil chamber had been debased in the grossest terms by the Sinn Féin leader.
We now have a situation where a member of the Dáil has linked two sitting TDs to a murder of a servant of the State. Mr Stack says the Sinn Féin TDs who supported Mr Adams "should hang their heads in shame", insisting the leader told "untruth after untruth". The Stack family has been delayed justice for long enough. If Mr Adams hoped to put this matter to bed, or to have set minds at rest, he has done quite the opposite. Years of presenting ideology as evidence has created a massive credibility deficit for Sinn Féin. But the party is now in the Dáil and cannot consider itself exempt from the standards of full accountability democracy demands.