St Patrick, in driving the snakes out of Ireland did not foster Irish bio-diversity. In that sense he was not a green saint. Indeed he was probably the pioneer in Ireland of the not-in-my-backyard attitude and of the exporting of problems to neighbouring lands.
On the other hand, as a foreigner himself who made what was previously pretty much the interest of a furtive minority into a national institution, he can be seen as a precursor of Jack Charlton. Both were men who took up the cudgel for a cause which was neither profitable nor popular, and retired to general acclaim, one the national patron saint, the other a freeman of Dublin.
If St Patrick can, at a stretch, be represented as an anti-environmentalist but industrious immigrant, we can hardly look askance at Cu Chulainn appearing as a loyalist champion after several decades in the nationalist camp.
The point is that every generation reads its heritage according to contemporary need: it sees the past in terms of the present.
Kevin Danaher has shown in The Year in Ireland that compared to the other great festivals of the year, the customs associated with St Patrick's Day were meagre. The present prominence of the festival is relatively new. Organised within an independent Irish State, the parades asserted new ideals of community in the union of state and civil society, the assertion of social partnership and the pre-eminence of the national church.
The razzmatazz of American St Patrick's Day parades has more recently provided the model for celebrating the day in Ireland.
If the millennium celebrations represented the first truly global event, then we have witnessed more modest versions of that for many years in the Irish media coverage of St Patrick's Day parades around the world, where the girl guides in Thurles and the police band in Boston can share a common, if transient, sense of community. St Patrick's Day in Ireland today is unthinkable without this global dimension.
And the very fact that the celebration of St Patrick in New York, San Francisco or Sydney is evidence of pluralistic, multicultural societies, so the feedback from them to Ireland allows these resonances to inform the Irish celebrations.
Globalisation has undermined the power of the Irish State - and every other state - to enforce cultural conformity. This has been reflected in the less monolithic, more playful St Patrick's Day parades of late.
Irish identity has always changed. The word Gael, originally meaning more or less a savage, was borrowed from the Celtic British. It was applied to the type of Irish miscreant who made the circumstances of Patrick's first journey to Ireland so unpleasant. Its use as an overarching term for the country's inhabitants seems to suggest some kind of emerging ethnic unity.
The Irish origin myth in the medieval Lebor Gabala, the Book of Invasions, for centuries informed the Gaels' ideas of their own ancestry. It traced the Irish back through Spain and Egypt to Scythia (John O'Donoghue please note).
The Anglo-Normans maintained a separate identity for centuries. Gael and Gall, Irish and "Old English", uneasily shared the same island until they merged as "Irish Catholics" - referred to in Irish simply as Eireannaigh - after the 17th century, distinguishing themselves thus from the new Protestant colonists. Already in the late 18th century, a new Irish identity was being proposed to unite, as Tone wished, Protestant, Catholic and Dissenter in a common Irishness.
The Gaelic Revival succeeded in creating an Irish identity based on a notion of a common ancestral Gaelic culture which, despite the Protestant progenitors of the revival, was accepted most of all by Catholics, and added language to land and religion, the core symbols of Irish nationalism.
Ireland was never ethnically or linguistically homogeneous in the last millennium. Ironically, as ethnic diversity grows, Ireland has perhaps never been as linguistically uniform as today. In an increasingly secularised Ireland, religion is in the process of retreating to the private domain, and there has been a gradual decoupling of ethnicity and religion in the South. Northern developments still offer the possibilities of Irish ethnic identities being freed from banal nationalism and banal unionism.
What kind of St Patrick will we need in the future and how will we celebrate him? He won't be Catholic or Protestant. He won't be green or orange, but will he even be white? As the controversy at the New York parade has already intimated, his sexual orientation will not be taken for granted. And what about his gender? Feminism has taught us that we already have a surfeit of male authoritarian figures.
And of course he wasn't Irish in the first place and didn't re-enter the country through orthodox channels. Should we make him the patron saint of illegal immigrants locked up in detention centres? Or should we scrap him and accept that the slave traders who were responsible for his sojourn in Ireland made an unfortunate error?
Or do we simply do what we've already been doing and reinterpret his symbolic role in the light of new needs?
No tradition can pass on without alternatives, without the possibility of borrowing, rejecting and reinterpreting. And that is constantly being done. The fact that St Patrick and St Patrick's Day already belong to millions of people who aren't Irish makes them the most inclusive of Irish symbols, and augurs well for St Patrick's continued relevance to a changing Irish society.
Diarmuid O Giollain teaches folklore and ethnology in University College, Cork