THE best aspect of the referendum outcome in Northern Ireland is not that it guarantees peace, or reconciliation, or constitutional stability, for it does none of these things.

What may yet prove to be the most enduring gain had actually happened ahead of the extraordinary result announced in Belfast on Saturday afternoon. It is that the tribal vote has been fractured. People found something to unite them which was bigger and stronger than the fears that had divided them for centuries.

The result was wonderful, but not so wonderful as seeing Joe Cahill and Gusty Spence, David Trimble and Gerry Adams, Martin McGuinness and Sir John Hermon, Bertie Ahern and David Ervine, Ken Maginnis and John Hume all on the same side of the argument. Or, indeed, of seeing almost as improbably alliances ranged against them. That, rather than the fact of a 71% vote for the Good Friday Agreement, was the dawn of a new politics in Northern Ireland.

Nor should we miss the significance of the vote in the Republic, which had a heavy weight of atavistic sentiment to shift. Thanks to the notorious conviction of much of the British media that news, like weather, barely exists beyond our borders (except, of course, in the

US: imagine if OJ Simpson had been Portuguese), the crucial importance of the constitutional amendment was easy to overlook. Without it, the deal would have been plausibly, maybe even justly, portrayed as void. Instead, it has the blessing of the island of Ireland.

There were moments when the campaign in the North did give cause to wonder whether the zeal of the ''yes'' side was verging on self-defeating excess. How much public commitment could you really read into a result which needed the con brio evangelism of Bill Clinton, Tony Blair, even the Lord High Bono to secure it?

The answer, of course, was the need to counter a ''no'' campaign which, despite having nothing to sell and a lavish collection of grotesques to sell it, managed to command the agenda for much of the time and focus debate on issues like decommissioning and prisoner release which played powerfully to old grievances. For that reason alone, if on no higher grounds, laying on away-days from the Maze for any gangster prepared to back the deal was a mistake.

But it worked. And while it is too much to hope that the intransigents will leave the field, their obduracy has lost its last claim to democratic credibility. Overlaying the familiar sectarian landscape at the assembly elections will be a new fault line between democrats (of however recent provenance) and the rest: those committed to making the deal work, and those not. A new politics.

Northern Ireland has been so awful for so long, that it has joined the ranks of forbidden metaphors. When you hear anything compared to Nazi Germany, you intuitively know the argument is going to be longer on hyperbole than perception.

Much the same applies to the Province; nothing else in these islands is remotely like what has happened there in the past 30 years, and for that we should be grateful.

But it is a measure of the moment that a cautious parallel can be drawn between Friday's vote and mainland, mainstream politics. It has to do with mandates. In British politics, mandates have long been counted among the spoils of victory. Put something in your manifesto, win the election, and you can proclaim the people's authority for your plans.

Friday's result shows that, when democracy is serious about engaging the people, there is a world of difference between a mandate and a majority. Fifty-one per cent would have been a majority. Seventy-one per cent is a mandate. It is the different between assent and consent, acquiescence and commitment, compliance and conviction.

Scotland's new politics has a very different context from Northern Ireland's, but it too aspires to engage the people as they have not previously been engaged. Here, happily, the alternative to engagement is only apathy, not carnage. Yet the principle surely is common, and it is that inclusiveness demands a limit to the licence of majority.

We've already come some way from the old simplicities of British electoral politics. Labour's devolution referendum may have been conceived in the first instance as an act of political expediency, yet the result legitimised and entrenched the Scottish Parliament as mere inclusion in a successful manifesto could not have done.

Or, if you prefer, there is the contrast between the SNP's sudden poll rise, and the virtually unchanging level of support for independence. The SNP have been smart enough to acknowledge what last week's Herald poll confirms, namely that being a sufficiently credible outfit to attract anti-Labour protest votes does not add up to a mandate for their flagship policy.

They've made no higher bid than for an opportunity for the people to confer, or withhold, a proper mandate for independence, an option that should anyway have been on offer last September. If the other parties are half as smart, they will take John McAllion and Donald Gorrie's advice, and agree - soon.

Imagine if the old affinities between Scotland and Northern Ireland, so long annexed by bigots in both countries, could be turned to the common search for a better politics, as Mary Robinson suggested last year. Perhaps that is too much to wish for just yet, and it is enough to hope that Northern Irish politics can at last find time for the sort of workaday issues that preoccupy the rest of us. For the moment, we can take pleasure in the Province having a positive political lesson to teach us. It's been a long time since that last happened.