Like many others throughout these islands I have been moved to tears by many of the countless moments of tragedy in Northern Ireland during the past three decades. But I also recall several joyous moments of deep emotion. One was when John Hume emerged from the final prolonged meeting with Ted Heath and Brian Faulkner on the first floor of Sunningdale and signalled with a thumbs-up sign from the balcony to those of us in the hall below that the final hurdle in the way of agreement had been overcome.
On that December Sunday of 1973 it seemed to me that this was truly a turning-point in the history of our island - as I felt my parents must have sensed when at Easter 1916 they had stood in O'Connell Street listening to Patrick Pearse reading the Declaratlon of Independence.
Sadly, Sunningdale proved to be a false dawn - and was followed by almost 25 years of appalling violence. Yesterday as I watched on television the concluding stages of the negotiation at Castle Buildings, I experienced again the same welling of emotion as at Sunningdale - combining relief and hope, and, again a profound sense of being present at a turning-point in the history of our island. But the Sunningdale memory is a sobering one.
We thought then that we had at last secured an enduring settlement of the centuries-old Northern Ireland problem. Could it be that this Easter week-end we are now deluding ourselves once again? I think not. For three factors that helped to bring down Sunningdale are absent now. First, parties representing the loyalist paramilitaries, who in May 1974 launched the deadly Workers' Strike, are signatories to this Agreement. Second, the British government that has helped to broker this Agreement has an impregnable majority and up to four years of power ahead of it; it is not vulnerable in the way that Ted Heath's government was 24 years ago. And third, on this occasion the Agreement is not susceptible to a constitutional challenge in our courts - precisely because it is to be backed by amendments to our Constitution.
It seems likely that both these amendments and the settlement itself will be endorsed in this State by a very large majority. And I would guess that, although in Northern Ireland there will be bitter opposition from some unionist politicians - and also rejection or at best abstention by some on the "republican" wing of Northern nationalism - the settlement will nevertheless be endorsed by a majority there.
On the unionist side the day will probably be carried by a combination of the yearning for peace that exists among both sections of the community in Northern Ireland, the reassuring impact of our constitutional amendments, and, we can be sure, a skilful presentation by the UUP leadership of the terms of this agreement as a negotiating success for them.
It was clear that for the UUP it was essential to be seen to have a late negotiating success. That party sought to achieve this effect by dramatising their negative reaction to the Mitchell document. But, early on Friday morning, after much manoeuvring, they were once again on board.
The credit for this whole extraordinary achievement is widely shared. John Hume was certainly the prime mover in this process. Ten years ago, at a time when, following the Anglo-Irish Agreement, Sinn Fein had lost one-third of its electoral support to the SDLP, it was John Hume who began to persuade Gerry Adams that Britain was no longer the source of the problem, and that the issue had now fundamentally shifted, to become one of Irish self-determination.
Of course John Hume's concept of Irish self-determination - by the peoples of North and South voting simultaneously but separately, rather than by a single decision by a simple majority of the Irish people in a single all-Ireland vote - was not Sinn Fein's. But over a period in the late 1980s and the early 1990s, he gradually won Gerry Adams over to implicit acceptance of this model - if accompanied by a significant component of all-Ireland institutions.
Had the SDLP leader not doggedly persisted with this campaign of persuasion, the change of approach by Sinn Fein/IRA that found expression in the Hume/Adams document would not have occurred.
But it also required imagination, leadership and courage on the part Gerry Adams and Martin McGuinness to abandon the "Armalite and ballot box" approach in favour of seeking a negotiated settlement. At Government level three Taoisigh in succession skilfully pursued the opportunity thus created. Albert Reynolds persuaded John Major to give official sanction to the Hume/Adams approach in the form of the Downing Street Declaration of December 1993. In February 1995, John Bruton secured British government support for the historic Framework Document - and a year later persuaded John Major to modify, albeit belatedly, Britain's hard-line position on decommissioning. In these achievements both were greatly aided by Dick Spring, as Tanaiste and Minister for Foreign Affairs.
And Bertie Ahern has now skilfully carried the ball right across the line. These political leaders have been supported by dedicated, skilled, and far-sighted Irish civil servants such as Sean O hUiginn, Dermot Gallagher, David Donohue and Paddy Teahon, but also by political aides such as Martin Mansergh - a key figure throughout most of the process - and Fergus Finlay.
On the British side Peter Brooke understood and ran with John Hume's concept of self-determination. And John Major, despite the problems of political arithmetic, brought the Conservatives further along the road to a Northern settlement than any of his predecessors.
To Tony Blair, and his highly committed and well-informed Secretary of State, Mo Mowlam, thus fell the opportunity to bring this process to a successful conclusion - and few will fail to give them credit for the commitment and skill with which they approached this task, backed by a high-powered civil service team.
A potent factor in creating - especially amongst Sinn Fein supporters - the climate of opinion that has made this possible has also been the supportive and well-judged involvement of President Clinton. And the United States also contributed the chairman of the negotiating process, Senator George Mitchell, who gave up three years of his life to what at times must have seen an unrewarding task. And no one will doubt that Seamus Mallon will be amongst the names to which history will pay tribute. Throughout this negotiation his steadiness, clarity, and rationality have won universal respect - complementing John Hume's long-sighted vision.
An enormous amount of work will remain to be undertaken after the endorsement of this Agreement by the peoples of North and South in six weeks time. But there is now a good chance that before this tragic century of Irish history ends, the island of Ireland will be firmly embarked upon a much happier chapter of its history.