THE RTE documentary Cork's Bloody Secret, which last week told of the IRA's campaign against local Protestants in 1922, will stand as a landmark document in modern Irish history.
This deeply moving meditation on the sectarian cleavages which gave birth to the Irish State was a master class on the importance of local history, and also a testament to human courage and solidarity.
Hazel Baylor brings her daughter to the grave of her uncle, John Albert Chinnery, who was murdered at his farm on April 28, 1922, by local IRA toughs; and the way she talks, in Irish, about their family's loss was as muscular as anything de Valera could manage from the platform.
Charles Duff came back from Britain to tell the story of his murdered grandfather, David Gray, the chemist who was shot dead in the doorway of his home in Dunmanway on April 27, 1922.
Having been written out of our national story for decades, these brave men and women performed a signal service to modern Ireland in reminding us of the catastrophic human consequences that followed the emergence of the IRA after 1919, especially in Cork, with its large, and mostly helpless, Protestant minority.
Their humane meditation on their loss must shame the hardmen in the local history profession in Cork who insist on painting the events of 1919-21 as a kind of knightly joust between devilish Black and Tans and heroic Flying Column men who preached an impeccable kind of republican virtue.
The knock on the door at night told a different story.
The most amazing aspect of this whole debate is the way it shows an almost total ignorance of Irish history pre-1919.
Anybody who knows anything about the century prior to the formation of the State would never dare to ignore the sectarianism that shaped every aspect of the Anglo-Irish relationship.
To write the sectarian hatreds out of the record, that is to say those very hatreds that motivated the squalid murders assessed by Cork's Bloody Secret, is not just to offer a kind of bad history.
It is a kind of anti-history, since it asks us to ascribe a sweetly, virtuous mindset to a Catholic class that had defined itself unashamedly in sectarian terms since Daniel O'Connell's astonishing career in the 1820s, if not before that.
There are many more Chinnerys and Duffs languishing in paupers' graves throughout the Cork countryside, and anyone who wants to characterise these events as "unauthorised" excesses or flashes in so many local pans only reveals their ignorance of the culture that produced them.
A pale and handsome young man once stood up in the British House of Commons to talk about these incorrigible sectarian tensions.
He dismissed the notion that Irish Catholics treated their Protestant neighbours with natural courtesy, and said "there is an old hereditary feud of blood -- there has been a transfer of property founded upon conquest -- and again, upon violent punishment for sanguinary rebellions, which is still unforgotten, and which lies at the root of the existing discord. Could you remove the immediate cause of debate, you would not thereby get rid of this fundamental difficulty."
The speaker was a young William Ewart Gladstone in 1836, channelling the mindset and the self-pity of the rural Irish Catholic class -- the very mindset that, by their own admission, animated the IRA in Cork in 1922.
Cork's Bloody Secret provoked many old ghosts and it was hard not to think of the great Protestant contribution to the Irish language during Hazel's moving remarks, a proud tradition that ranged from William Carleton through Douglas Hyde and TK Whitaker.
One also recalled the fact that de Valera let it be known through Maurice Moynihan in the 1980s that he felt deep shame in his old age when confronted with some of his speeches from the 1918-22 period, especially his speeches denouncing the RIC as a force of traitors, speeches which he knew provoked the sorts of outrages which destroyed Hazel's family.
These regrets can be found in Moynihan's editorial notes in his great book, Speeches and Statements by Eamon de Valera.
The great historian of the French Revolution Thomas Carlyle also pushes his way into this debate, since he wrote an extraordinary book about Ireland during the famine era.
Having spent some time in the family church at the Beecher estate at Ballygiblin in Cork in 1849, Carlyle wrote about his fears for honourable Irish Protestants and the storms he saw on their horizons: "I feel how decent English Protestants . . . might with zealous affection like to assemble here once a week, and remind themselves of English purities and decencies and gospel ordinances in the midst of a black howling Babel of superstitious savagery -- like Hebrews sitting by the streams of Babel . . . Weep ye by the stream of Babel, decent clean English-Irish."
Carlyle was wrong to call Cork Protestants English-Irish, since they were just Irish at the end, and he was wrong to predict much future weeping. Their's was to be a tradition of silence, rather than tears.
As Hazel says in her interview: "Thainig tost mor agus ta an tost sin fos ann inniu."
This was not the voice of Babel; rather the lonely murmur of abandonment, death-like in the leafless trees.
John-Paul McCarthy teaches Irish history at Exeter College, Oxford