It has served brilliantly in its mission of helping to keep the two traditions apart. Today, at the age of 70, Paisley is in the thick of the multi-party talks at Stormont, as fundamentalist a Protestant as ever, as central as ever to the Northern Ireland political scene, and once again an obstacle to agreement.
Ian Paisley was ordained a minister in the 1940s. By the 1950s he was figuring in bitter religious controversies; by the 1960s he had become a formidable street demagogue. Age may be slowing him down a little, but his record of 26 years in the House of Commons, and 17 in the European Parliament, serves as a standing rebuttal of the proverb that travel broadens the mind.
He still says today what he said in the 1960s: that Ulster is in peril from the IRA and the Vatican, that the Protestants cannot trust British governments, and that they must act to safeguard their heritage.
The tragedy is that one of the brightest, most subtle and most perceptive minds of his generation should have opted, at every key juncture in his long career, for confrontation rather than accommodation.
It has been an extraordinary career - in politics, in the pulpit, on the streets, in jail (twice, for protesting); a career packed with incident and drama, with a thousand demonstrations, walkouts and calls to arms. The reason why Ian Paisley is the "Dr No" of Irish politics is because he is not a politician with a sideline in religion; he is a fundamentalist evangelical minister who is in politics.
In his memoirs Maurice Hayes, a retired Catholic civil servant who has known Paisley for more than three decades, gives a thumbnail sketch of this multi-faceted character.
"I have often thought there are about six Paisleys," writes Hayes. Two of them are very nice people, two quite awful, and the other two could go either way. What I have to report is that he never told me a lie, never breached a confidence, and ... he worked unceasingly for all his constituents regardless of religion.
"True, he could be, and was, a rabble-rouser. He very often filled the atmosphere with an inflammable vapour that other people could and did ignite... He did not, I think, use his church as a platform to gain political power. Rather, he entered politics to secure the fundamental religious values to which he is attached."
The Free Presbyterian church, of which Paisley is moderator for life, has a much smaller membership than the votes he amasses, but it is the core of his being.
His preaching style is melodramatic and much concerned with Catholicism. His vocabulary is unchanged from the days when James Callaghan accused him of "using the language of war cast in a biblical mould". Congregations continue to be bombarded with talk of the Papal Anti-Christ in the Vatican, the maws of Rome, the mother of harlots, the blasphemous mass, and warned of Irish Catholicism's "continuous and concentrated campaigns to eliminate the Protestant community."
Donald Soper once called this style cabaret, describing Belfast as a city of many religious nightclubs. It is certainly true that many of the old dears who come to see Paisley clearly enjoy the service hugely, to the extent that it can seem as much entertainment as worship. Tape recordings are available at the end of each service.
It is also true that Paisley's technique of thrilling and frightening his listeners with the demonology of Rome, along with the fear of damnation, can lead to him being viewed as an evangelical Protestant version of Vincent Price. But it is a fundamental error to conclude from his theatricality that his religion is not genuine.
Nothing could be further from the truth. He is remarkably learned in his theology. His Protestant faith is deep, sincere and unshakeable: so too is his conviction that the Pope is in league with the devil. He told Pope John Paul II that to his face, confronting him on a visit to the European Parliament by shouting "I renounce you as the Anti-Christ."
He once outlined his philosophy to his flock in his huge Martyr's Memorial church, the Belfast headquarters of a church that has branches in England, the Republic and Canada: "You've got to take your stand, you know. There's not going to be any compromise. If you compromise God will curse you. If you stand God will bless you. That's why God has blessed this preacher and this church."
As in religion, so in politics. When he looks at non-Unionists in Northern Ireland he sees not nationalists or republicans but, primarily, Catholics. He puts his religion before his politics - and indeed higher than the crown, for he has made it clear that if the British monarchy ceases to be Protestant then his loyalty to it will cease.
It is small wonder, given this deep-seated aversion to compromise, that he has caused so much grief to British politicians who have dealt with him.
Reginald Maudling, a former Tory Home Secretary, found him "one of the most difficult characters anyone could hope to deal with. I always found his influence dangerous." William Whitelaw, a former Northern Ireland Secretary, marvelled at his "unrivalled skill at undermining the plans of others. He can effectively destroy and obstruct, but he has never seemed able to act constructively." James Prior thought him "basically a man who thrives on the violent scene. His aim is to stir the emotions of the Protestant people. His bigotry easily boils over into bombast." Meetings Paisley held with Margaret Thatcher and John Major have ended close to uproar.
It is an indication of the complexity of the man that Maudling, Whitelaw and Prior, while criticising him so sternly, also commented wonderingly that in private he could be charming, friendly and engaging. Part of the exasperation of British ministers springs from his proficiency in the politics of alarmist denunciation, for he continually portrays British governments as conspiratorial and treacherous.
But another reason is the charge that Paisley has aggravated already dangerous situations. One ex-minister said: "It's all very well to say he's giving voice to genuine Protestant fears and worries, but it's more than that. He feeds the paranoia and reinforces it. He amplifies it."
A frequent criticism centres on his recurring forays into the murky underworld of extreme loyalism, when he goes beyond rhetoric and makes an alliance with men in masks. In doing so he has displayed less consistency than he does in matters religious. In 1974, for example, he co-operated with the largest paramilitary group, the Ulster Defence Association, to stage a loyalist general strike. The following year he denounced them as loyalist killers engaging in crimes "just as heinous and hellish as those of the IRA". But two years later, in 1977, he was back in alliance with them to stage another stoppage.
Up to a dozen times over the years, Paisley has urged Protestants to form a "third force" to take on the IRA. Sometimes these calls have involved shows of force: in 1986, for example, 4,000 men, many masked, staged a nocturnal parade through the County Down town of Hillsborough.
On another occasion journalists were brought to a County Antrim hillside at dead of night, to find 500 men drawn up in military formation, brandishing pieces of paper. Paisley explained these were gun certificates, declaring: "I will take full responsibility for anything these men do. We will stop at nothing."
Critics say such behaviour can help to provoke impressionable Protestant youths to join paramilitary groups and become involved in actual, rather than rhetorical, violence. There is evidence that he can have a similar effect on the republican side.
In the 1970s a Protestant minister asked IRA leader Daithi O Conaill about a rumour that the IRA would try to kill Paisley. He recalled: "O Conaill just simply told me: 'There's no way we would kill Ian Paisley. Paisley is the best recruiting sergeant we've got.'" O Conaill said of Paisley's threats that the Protestant people would take the law into their own hands: 'When the Catholic community hears that, a chill goes down the spine of every Catholic in west Belfast, and after that we have no trouble in getting volunteers, safe houses and money.'"
There have been the few occasions where Paisley has surprised and unnerved opponents by taking an unexpectedly moderate line. With hindsight, however, these can be seen as tactical sallies to eat into support for the Ulster Unionists, the largest Unionist party.
The fact that it is the largest Unionist party is one of the banes of Paisley's life, since it means that his own Democratic Unionist party is forever number two. Yet the gap between the DUP and the UUP is not as big as people assume; and herein lies Paisley's deeper political significance.
Because David Trimble's UUP has nine Westminster MPs while Paisley has only three, many casual observers tend to assume that the DUP is something of a fringe element. The statistics confound this. In Westminster elections Paisley takes on average 12 per cent of the vote, but this is not a true measure of his support, since in these contests many Unionist voters cluster around the UUP as the party most likely to win seats.
When the results of other elections - for councils, assemblies and Europe - are analysed Paisley's support soars. In this year's forum election Trimble took 46 per cent of the Unionist vote: Paisley took 36 per cent and a close associate won another 7 per cent. Paisley voters are by no means all evangelical, but they are certainly voting against compromise.
In other words Paisley is not some peripheral phenomenon: he can in fact credibly claim to speak for four out of every 10 Unionist voters. This level of support is not enough to take control of Unionism, but it is certainly enough to exercise a powerful inhibiting influence on the Ulster Unionists. Any Unionist leader contemplating an accommodation with nationalists knows that doing so would produce a furious Paisley onslaught.
To put it at its bleakest, Paisley's level of support, together with his forcefulness and political skills, may well be enough to ensure that, as long as he is on the scene, there will never be political accommodation between Unionist and nationalist. His lifelong preference for conflict over compromise means he would regard this as a victory for his fundamental religious values, and doubtless means he will be proud to have that as his epitaph.Reuse content