There can be something akin to love between peoples. In the debate on Scottish independence this seems too often forgotten. Divorce lawyers' bickering over currency arrangements, nuclear weapons and economic advantage takes precedence over appraisal of what is at the heart of the marriage.
We are, after all, talking about breaking up a love match. It did not begin as one, but it came to be one, and was long celebrated as such on both sides. Then it cooled. Yet although bonds of this kind can erode, they can also be revived. Separation, as we know from the lives of individuals, can be ruinous for one or both partners. Or, in this case, four, since Wales and Northern Ireland are in the same household. Do Scots understand how frightened the English are? How mournful, under an apparent insouciance, that things have come to this pass? This is not the resentment of which some nationalists complain: it is an apprehension of loss.
The Anglo-Scottish-Welsh enterprise is a joint achievement of all three nations. It began with English dominance but ends in English need – for company in what could be a tough 21st century, for continuity with the past and for a comradeship valued far more than is usually expressed. The admiration and affection the English have for Scots is different from that they feel toward, for example, the French. There came to exist a commingled patriotism, exemplified by Sir Walter Scott, in whose canon Quentin Durward and Ivanhoe happily co-exist. It is one in which each country's heroes, whether military, literary or intellectual, are to an extent shared. Who do the Scots think the English were rooting for when they saw Braveheart? It was not Edward I.
A loving partner, or even a partner who had ceased to love but still cared, would ask what would be destroyed as well as what would be created if the partnership ended. It is too easy to argue, as Alex Salmond did in his Hugo Young lecture, that "an independent Scotland would be a beacon for progressive opinion south of the border". Or that a nebulous "social union" would continue, which suggests that Britain, although physically ended, would still be around as a sort of friendly ghost. On this optimistic reading, independence for Scotland would be a brave new beginning for England as well. Unproven and unlikely.
Much more likely is that the impact of a Yes on England's self-esteem, identity and politics would be profoundly negative, while the effect on Wales would almost certainly be to take it out of the United Kingdom as well. The end of the United Kingdom, for a long time the most successful multinational state in Europe, would be no light matter.
When these marriages end, they do not usually end well. Scots should look toward the two states once united as Czechoslovakia, which separated 20 years ago, and Canada, where Quebec separatists have taken the province into two independence referendums. Partition, whether completed in the Czech and Slovak case, or still a work in progress, as in Canada, has made almost nobody happy. Czechs regret their separation from Slovakia. Slovaks are more sanguine, yet both peoples are still perplexed at how and why they dissolved their union.
A kind of melancholia is evident in discussions of what happened. At a recent conference in Prague a roomful of Czech intellectuals were asked whether they regretted the change. Virtually every hand went up. The Canadian example is another cautionary tale. Canada has stayed together, but there is a very cold relationship at the heart of the Canadian polity.
In both Czechoslovakia and Canada, union was a more arbitrary affair than with Scotland and England. In Canada a remnant of the French empire had to be melded with a remnant of the British. Czechs and Slovaks began as enthusiasts for a joint republic after the first world war but, unlike the Scots and the English, they had no history of long-term cooperation. Their break-up, actual or potential, has, in other words, more reason to it than an Anglo-Scottish parting of the ways.
The heart, in any case, has its reasons of which reason knows nothing. In The 39 Steps, John Buchan, who saw no contradiction between being a Scottish nationalist and a British patriot, sent his Scottish hero north of the border to save the Empire. If Richard Hannay were not a fictional character, he would be turning in his grave today. Are these just played-out myths, as Linda Colley would have it in her new and rather desperately neutral book on the UK? Perhaps, but the Scots should know this: if you leave us, we will miss you in our hearts. And you will miss us.
Martin Woollacott is a former foreign correspondent, foreign editor and commentator on international affairs for the Guardian.