Today provides a footnote to recent discussion of how we Kiwis should celebrate our nationhood. Most of us are split personalities, one part of us linked to this land in which we were born, the other part linked to the homes of ancestors.
For the first settlers, Maori, centuries have all but eroded their links back to island Polynesia whence their tupuna set sail in their great canoes.
But for non-Maori, those of us who accept our designation as Pakeha, identifying us as Kiwis with an equally significant umbilical attachment to this land, we also celebrate the lands from which our ancestors sprang.
None more so than the Irish, and never more so on this day, the feast of the great St Patrick.
This is the one day above all others when I, as the great-great-grandson of an Irish colour sergeant, Andrew McMahon, who came to New Zealand as a fencible soldier in 1849, feel that same sense of divided loyalty which must tear at the hearts of my Maori mates as they grapple with the pride of being a New Zealander, and the sense of obligation to those to whom they owe respect, gratitude and love for being their ancestors.
I am fiercely proud to be, and feel privileged to be, a New Zealander, one of the chosen of God's Own Country. But I'm almost as equally proud of my Irish heritage and for good reason. Let me explain.
The Irish are part of a larger ethnic grouping called the Celts who first entered western consciousness about 600 BC, only a century and a half after the legendary founding of the City of Rome. Celts settled in what is now France, Spain, Turkey and Britain.
British Celts were later pushed by Angles and Saxons into Cornwall where they would become Cornish, and into Wales, where they became the Welsh. About 350 BC, some 50 years after Celtic tribes began their invasion of Britain, they reached Ireland. Some came by way of Britain, but most are believed to have come from Spain.
For some nine centuries, Ireland had an illiterate, aristocratic, semi-nomadic, Iron Age warrior culture, its wealth based on animal husbandry and slavery.
It remained largely wild and untamed until the 5th century AD and the arrival of the man who began civilising Ireland, a newly created bishop whose youth had been spent as a slave in Ireland after he had been kidnapped from Britain.
He was Patricius, now venerated as the great St Patrick, who turned the Irish to religion, learning and the writing of books.
So it was that Ireland, a little island at the edge of Europe, had its moment of incomparable glory. As the Roman Empire fell, as all through Europe, unwashed barbarians descended on Roman cities, looting artefacts and burning books, the Irish, who were just learning to read and write, took up the great labour of copying all of western literature.
These scribes then served as conduits through which the Greco-Roman and Judeao-Christian cultures were transmitted to the tribes of Europe, newly settled amid the rubble and ruined vineyards of the civilisation they had overwhelmed.
It was Irish monks who single-handedly re-founded European civilisation. In white druid-like robes, they fanned out across Europe, founding monasteries which became great cities. Wherever they went they took their books, and they brought their love of learning and their skills in making books.
They saved civilisation, and but for them, we would not know, even here in New Zealand, the modern, generally civilised way of life which has come to us from Europe.
That was the land, and they were the people from whom I and other Irish Kiwis are descended, the saviours of civilisation.
This is also the land that recognises its links with those who can claim Irish heritage. Article 2 of the Irish Constitution states: "It is the entitlement and birthright of every person born in the island of Ireland, which includes its islands and seas, to be part of the Irish Nation ... Furthermore, the Irish Nation cherishes its special affinity with people of Irish ancestry living abroad who share its cultural identity and heritage."
That's why today is so special for those of Irish descent. Thanks to the blending of what tikanga Maori has taught us, and what's been learned from Irish and so many other ethnic migrants to Godzone over the years, to be a New Zealander now is as special and pride-inspiring as it is for those of Irish descent today.
• Terry Dunleavy MBE, a writer of Takapuna, is a fourth generation New Zealander.