Northern Ireland: For a long time Ireland's history was a list of bad things the English had done.
Then the revisionists said hang on, it wasn't like that. In Derek Lundy, author of the Men that God Made Mad, we have a new voice doing the same work, challenging our pieties and, in the process, helping us Hibernians to grow up.
The title of his book - a mix of history and memoir - is from GK Chesterton: "The Great Gaels of Ireland,/ The men that God made mad,/ For all their wars were merry,/ And all their songs were sad." There's little merriment here, and even less singing, but plenty of violence for this is the author's subject.
He also savages our tribal predilections, though he lashes all parties with equal vigour and favours none. He loathes the cherished nationalist belief in exceptionalism, the idea that Irish Catholic suffering was in a different league to that of everyone else in history, and equally he abhors the unionist belief that everything other, for which read Catholic, is so dangerous it must be spurned.
The author is a Canadian national whose Ulster Protestant parents emigrated from Belfast when he was a child but who returned periodically throughout the second half of the 20th century to visit grandparents and family. At the heart of this book are the biographies of three relatives.
The first (and if he's not a relative - and that isn't proved - then at least they share the same significant surname) is Robert Lundy, military governor of Derry in 1689 when the Jacobite army came to take the city.
The second is the New Light Presbyterian minister, William Steel Dickson, a political radical who survived the 1798 rising by a whisker and maintained his enlightened United Irishmen views to the end of his life.
And the third is William Lundy, known as Billy, the author's grandfather. Born in 1890, he was a pugilistic Protestant shipyard worker (he helped build the Titanic) who signed the Solemn League and Covenant against Home Rule, ran guns before the first World War for the UVF, joined the British army in 1914, was kept by injury out of the Somme, and remained a committed bigot to the end of his days.
With the lives of these three as his threads - and how fortunate is Derek Lundy that they lived at such crucial periods - he takes us through Ulster and Ireland's history from the Norman conquest to the present, toggling between his micro stories and the macro picture. It's a felicitous technique, for his family biographies are a sturdy bannister in the midst of so much history; they also synchronise perfectly with his theme, which is the distance between what happened and what is thought to have happened, and why the truth is forgotten and untruth flourishes.
TAKE ROBERT LUNDY, for example. What everyone thinks they know, at least if they're Ulster Protestants, is that he was the closet Jacobite who wanted to surrender Derry and her refugees to the murdering Irish. However, before he could do that, he was toppled by a coup and fled the city disguised as a common soldier.
Of course Lundy wasn't a traitor, as the author demonstrates, just a professional soldier who didn't fancy Derry's chances. But that's beside the point: the Lundy fashioned by the Protestant imagination since the siege was vital to their story as they saw it.
People who feel insecure must have a Judas story they can copy obsessively. Thus, ever since the 17th century, Protestants have been expelling so-called traitors and saving themselves, with the most recent example, though the author doesn't make the connection, surely being David Trimble.
The distance between what happened and what is believed is a rich subject, and Northern Ireland's history as it has come to us is stuffed with lies. But it is not just the lies Protestants tell themselves, such as the ones about Lundy, that concern the author. He also explores the lies Catholics (or republicans or nationalists) told about Protestants, especially those told by the revolutionaries who created this state.
It is bracing to be reminded just how wrong our founding fathers were. It is also salutary to be reminded of the lies the majority on this island told about the minority population through most of the last century, while at the same time wanting to absorb them and, for 30 years, allowing the IRA to attack them from inside the State.
AS THE RECENT riot in Dublin's city centre showed, little has changed. Though some of the participants were opportunists, others were chips off the old irredentist block. Yes, the rioters said on our behalf, we believe in freedom of expression just as long as what are expressed are the old approved pieties. Unionists have been complaining about this for years but we still don't seem to have heard them. Perhaps Lundy can help us because if we're going to mature we must face these things.
To that extent, providing we're open, the author is providing a massively important service to our collective psyche with his book. True, not all his propositions will be welcome but he writes so charmingly, so nicely and so wittily, I think even the most hard-hearted Irish nationalist will find it hard to resist him.
• Carlo Gébler is Arts Council of Ireland Writer Fellow at Trinity College, Dublin. The paperback edition of his The Siege of Derry: A History will be published this month
• Men that God Made Mad: A Journey Through Truth, Myth and Terror in Northern Ireland By Derek Lundy Jonathan Cape, 351pp. £18.99