Even though we have had an independent Republic for over half a century, it is a curious historical fact that the main national objectives since the days of Daniel O'Connell have never been precisely realised.
More than Repeal was achieved in 1922, but over less than the whole country. Notoriously, Home Rule came only to the north-east corner of Ireland that had most strongly resisted it, and continues to be available, though not in operation, under the Belfast Agreement.
The Republic formally declared in 1949 governed only the 26 Counties. The Belfast Agreement may give us an agreed Ireland, but it is not a united Ireland. Despite our presidency of the European Union, there is no consensus on writing Emmet's epitaph just yet.
National objectives unrealised acquire a certain metaphysical quality with every desirable attribute attached to them.
Since debate about a united Ireland will continue, it may be useful to set out the principles that would require to be satisfied for any serious negotiation.
First, the Belfast Agreement provides the framework and prolegomena for any change in Northern Ireland's constitutional status. The principle involved is concurrent self-determination, in other words, requiring the agreement of the people of the North as well as the people of the whole island.
The question of a united Ireland remains open. However, if it is not possible, acting in good faith, to make all the institutions of the agreement work, and thereby establish the necessary trust and co-operation, can we persuade people that something far more ambitious could work better?
Secondly, unity has to be brought about peacefully, by agreement and without coercion. Paramilitary organisations have no role whatever, and their continuing activity is an unattractive advertisement for the cause they champion. The attempt to force the issue was disastrous, and did not bring a united Ireland close, despite all the lives lost. The most telling phrase in the Downing Street Declaration inserted by John Hume stated that it is for those who believe in Irish unity to persuade those who do not.
Thirdly, a divisive referendum, which is unlikely to produce a majority for change, should not be held for propaganda purposes or for intimidating either community with the likelihood of a demographic victory next time round. The calling of one is largely at the discretion of the Northern Ireland Secretary of State.
Ideally, a referendum in both parts of the country should follow rather than precede a negotiation. It can be taken that the people of the South would only agree to arrangements for a united Ireland, if continued political stability and economic prosperity could be reasonably assured and no massive costs were involved.
Fourthly, dual citizenship and the obligation of impartial government would survive any constitutional change, as would the option of continuing with existing institutional arrangements based on responsibility-sharing devolution.
It is a moot point as to whether the unionist community would be best served by an arms-length devolved arrangement with a unionist (and a nationalist) veto or by a more unitary system. Albert Reynolds as Taoiseach offered 30 per cent guaranteed Northern representation in a coalition government, at least for a transition period. The offer has not been withdrawn.
Fifthly, a united Ireland would have to be built on respect for the ethos and achievements of the Republic on the one hand, and of Northern Ireland on the other, with parity of esteem for both traditions there. The choice would be either to fuse the best elements from all sources, or alternatively to allow different sectoral regimes to co-exist in the one island, or a mixture of both. Confederation, federation, devolution, unitary state without devolution, constitute the main options, first set out in the New Ireland Forum Report in 1984.
Sixthly, in relation to symbols and the constitution, the sort of creativity that brought unexpected agreement on the PSNI badge would be needed. The basis of a language policy, embracing both Irish and the Ulster-Scots tradition, is already discernible.
Seventhly, there would have to be agreement on fundamental principles of foreign policy. A closer structured relationship with Britain and America consistent with sovereignty, as well as full membership of the European Union, including the euro, should not present too much difficulty.
The precise extent of Ireland's defence engagement might be more contentious. Seán Lemass predicted in his 1959 Oxford Union speech, "the question of the relationship between a united Ireland and the Commonwealth would be a main item on the agenda".
What are the advantages of a united island? Essentially, to give the people of Northern Ireland a far more direct and influential say in their destiny, visible representation at international level, the benefits of social partnership, and full participation in what could be the most dynamic knowledge-based economy in Western Europe. They would have more ownership of a richly varied and internationally recognised Irish cultural heritage.
A delegate at the Alliance Party Conference in Antrim last Saturday observed, there is no Intel with 4,000 jobs in Northern Ireland (nor likely to be), and, if the North wants anything, they first have to agree among themselves and then seek permission from Gordon Brown. The island of Ireland would undoubtedly carry more weight than the Republic on its own, and would enjoy much international goodwill.
Religious ascendancy is gone forever. Protestants and Catholics can be partners and friends. In the late 18th century, there was a profound belief amongst people of all traditions that Ireland could govern itself.
That has been demonstrated, especially in a European context. This State will continue to move forward strongly anyway, but it would be strange, if we, who are now drawing in thousands of immigrants each year, could not welcome any future expression of interest by people in Northern Ireland in exploring the possibility of building a new state between us.
It could yet provide a more attractive future for those of British and Protestant stock in the six Ulster counties of Northern Ireland than the relative backwater of the Union.