I note that you decided at your conference to form a group of Sinn Fein visionaries to plot 'a road-map' to Irish unity.

Having failed to achieve your goal by force of arms, you have concluded that political persuasion is a better alternative and I hope your 'road-map' group continue to steer in that direction.

I thought this St Patrick's Day and Easter Week would be an appropriate time to pen this letter to you mainly about your continued aspirations for a 'united Ireland'.

The words are in quotes deliberately, because even you might agree that a united Ireland is not definable in the 21st century in the way that it might have been in the 20th.

Of course, the big date ahead for you and your party, let alone the rest of us who don't share your ideological views, is Easter 2016. Only eight years to go and the clock ticking louder than any timebomb from our Troubles.

The question is, where will you, Gerry, and I be on the 100th anniversary of the Rising? Do you really believe you can achieve your long-standing wish by that date?

The mists of time enshroud the Easter Rising. There was a great deal more interest in the Irish Grand National at Fairyhouse that famous Easter Monday than there was in the motley band taking over the GPO in O'Connell Street. When racegoers returned in their thousands to Dublin that evening, counting their winnings and losings, just as another generation will do next Monday, most of them hadn't the foggiest idea what was going on.

Let us remind ourselves of what divided Ireland in 1916, even what still divided it when the 50th anniversary of the Rising was marked in 1966.

This island, north and south, Protestant and Catholic, was then devoutly religious.

Loyalty to Britain was intense among most Protestants. They feared being consumed in a priest-ridden State. They saw a Catholic Church with not a hint of compromise in its soul. Ecumenism was a very dirty word.

Up north, my father and yours lived in a state which, to quote Lord Brookeborough, was governed by 'a Protestant parliament for a Protestant people'.

Wherever you looked, the Union flag flew prominently and proudly. Ulster was British through and through and most Protestants believed it would be so forever.

In the end, we all ended up in a fight. There was you, young Gerry Adams leading western Europe's most ruthless underground army.

There was Ian Paisley shouting Never, Never, Never from the roof-tops of east Belfast. The rest is a terrible memory but we can look back in anger or we can look forward with hope.

What I'm coming to Gerry is this. How do you define a 'united Ireland' in today's world? This is not 1916 nor 1966.

Secularism is rampant, north and south. Bono and Westlife have become more important than any Catholic or Protestant bishop.

Wherever you look, the old images of 1916 and 1966 are fading away. The once quaintly-backward, impoverished Irish are now among the richest, smooth-talking nations on Earth.

Their thatched cottage land has become millionaires' row. The border has all but disappeared. The Irish president pays many more visits to the British north than any King or Queen ever did. The Queen's daughter watches rugby at Croke Park. Paisley drinks tea with Bertie Ahern.

It seems to me that unity today can be defined in many different ways and owes less and less to the out-dated ideology of the past? For example, unity in the sense that so many European states are in the Common Market, but still harbour huge differences in social and cultural outlooks.

Unity in the sense that the United States shares so much but still displays wide variations across its individual states.

Unity in the sense of the United Kingdom, where Scotland, Wales and certainly Northern Ireland have much in common with England, but also deep-seated differences. Extending that argument, I could argue that Ireland is already united but that it is actually two states, increasingly interlocking, inter-dependent, inter-woven, but not UNITED as was the simplistic dream of 1916 and the founding fathers of Sinn Fein. And, of course, the big stumbling block for you, Gerry, in charting your 'road-map', is simple economics. How do you fund Northern Ireland in your unitary state? How much would it cost the people of this island to replace Britain's billions?

Is it not the case that your constituency of West Belfast is more dependent on the British Welfare State than any other corner of Northern Ireland? Who pays if that support ends? So I await with interest the findings of your 'road-map' group. In particular, how they propose to finance the post-2016 united Ireland of your dreams.

Having said all that, I think there is little doubt that we are closer to Irish unity, whatever that term may mean, than at any point in my lifetime.

It is not only Irish republicans like Gerry Adams who are having to redefine what they mean by Irish unity.

Unionists of whatever hue needs to define for a modern audience what they means by unionism today as they grow further from London and closer to Dublin.

That is a subject for another day but as I watched Mr Paisley and Martin McGuinness side by side and being warmly applauded at the opening of Victoria Centre this month, I couldn't help thinking how far we had come in my lifetime. James Connolly. Eamonn De Valera, Sir James Craig and Lord Edward Carson, must be spinning in their respective graves today.

The world has moved on. Gerry, I wish you luck seeking the Holy Grail of Irish unity and all in the space of eight short years from this St Patrick's Day.

The Ireland which nurtured Sinn Fein a hundred years ago is not the same Ireland as 2008. But, whatever your road-map to 2016, let us hope the journey will continue to be peaceful, unlike that which brought us to this point today.

Yours, Ed