Sometimes, people think that this idea was the invention of a visiting academic to our shores, or a policy emanating from London or Dublin civil servants.

In fact, it was first proposed in a major public way by an Ulsterman, John Cole, the well-known journalist and BBC political editor.

In 1969 he was deputy editor of the Guardian and, as the conflict deepened in August 1969, he recommended a 'crisis coalition' in an editorial of August 16.

In his political memoirs, As it Seemed to Me, published in 1995, Cole explained why he adopted the idea of power-sharing as the only solution for such a deeply divided society as Northern Ireland.

He argued that the basic reason why the political system had failed in Northern Ireland was not due to 'original sin', or badness on people's part. Politics had failed "due to an impossible political conundrum". By 'conundrum' he meant puzzle or problem.

The conundrum was a simple one. He said: "Because the national issue dominated politics, and because unionists were in a permanent majority in the population, the Unionist Party was permanently in government." This meant that "the swing of the pendulum, the essential ingredient of democracy, was missing".

He believed that the solution was to establish a form of government in which both sides could be represented. This was essential to deal with a situation which was basically undemocratic in effect and which failed to meet the needs of a deeply divided society. Cole would now promote the idea of a power-sharing government for Northern Ireland and others would also back this approach.

A Government White Paper of March 1973 stated categorically that any new executive could 'no longer be solely based upon any single party' if that party drew its support and representative from 'only one section of a divided community'.

In late 1973, the leadership of the Ulster Unionist Party, the Alliance Party and the Social Democratic and Labour Party agreed to form an Executive. On January 1, 1974 the new Executive, under Brian Faulkner, took office, but on May 28, 1974, he resigned and the Executive collapsed.

The main reason was widespread opposition to the new arrangements from other unionists organised under the United Ulster Unionist Council. Their protest culminated in a strike by the Ulster Workers Council.

Other contributory factors behind the collapse of the Executive included an increased IRA bombing campaign and over emphasis on the Irish dimension by the SDLP and the Irish government.

After the fall of the Executive and Assembly, a Convention was elected in May 1975 to discuss ways forward. Initially, inter-party talks seemed to offer no progress, but in August Bill Craig, who had strongly opposed power-sharing, came up with a new approach.

He argued that Northern Ireland faced a very serious emergency and, like Britain during the crisis of the Second World War, they should look into the possibility of a voluntary, fixed-period government coalition with the SDLP.

For a time, his idea seemed to receive unionist support. But then, on September 8, 1975, the UUUC said they "could not agree to republicans taking part in any future cabinet of Northern Ireland".

By 'republicans', it should be pointed out, they meant the SDLP. In fact, the SDLP was led by the constitutional nationalist and socialist Gerry Fitt, who had served on the convoys to Russia during the Second World War and who had lost a brother in the Irish Guards in Normandy in 1944.

His opposition to republican violence would lead to his exile and he would later be elevated to the House of Lords. In 1975, however, members of the UUUC would not trust him or other party members in government.

Whether or not this attempt in 1975 at forming a government with representatives from both communities could have gone farther and have achieved success, we will never know. What we do know is that - incredibly - it would take more than 20 years and several thousand deaths before politicians would return to this idea of power-sharing as the best means of governing our divided community.

The concept of power-sharing was a key feature of the Belfast/Good Friday Agreement. Eventually, a cross-community Executive, led by David Trimble and Seamus Mallon, was established. It achieved some success, but encountered various difficulties which led to suspension. New Assembly elections resulted in the emergence of the DUP and Sinn Fein as the largest parties and, after negotiations, a new Executive, headed by Ian Paisley (later Peter Robinson) and Martin McGuinness.

The potential of such arrangements was well brought out by Ian Paisley in a speech in New York in April 2008. He stated: "I'm not given to exaggerate when I describe things, but we have had a miracle in Northern Ireland. . . The two sides in the dispute, if we might use these words, have come together and there is a greater understanding of what motivates each side."

Ongoing divisions in the Executive can be accepted as part of the everyday life of party politics. What is not acceptable, however, is that there should be any talk of upsetting, or ending these power-sharing arrangements.

We are still a deeply divided society and it is necessary that we have a form of government which allows all sections to be represented. Our 'conundrum' has not gone away.

Power-sharing is an essential part of the new accommodation, indeed, the 'miracle', which our society has achieved.

We must guard it carefully.

Professor Brian Walker is a member of the School of Politics at Queen’s University, Belfast