For a long time now, the case for the United Kingdom has been made in a tiresomely negative sense. That is, Unionists have spent more time pointing out the practical and procedural difficulties that are an unavoidable consequence of Scottish independence. This is fine as far as it goes. The problem is that, however justified these concerns may be, it does not go very far.

After all, practical difficulties are the things politicians are elected to solve. Or at least ameliorate. The case for the Union needs to be about something bigger and better than that. Unionists don’t simply need a plan, they need a story.

So it was braw to read Chris Deerin making what he termed the moral case for the Union in the pages of the Scottish Daily Mail last week. The Guardian were sufficiently interested by his argument to publish an edited version of it themselves.

The essence of Mr Deerin’s argument (I suppose I should say that he’s a pal of auld acquaintance) is simple: Britain is a great country and we should remember and pay attention to that more often than we do. Why would anyone wish to leave a great and successful country?

This was less a moral argument for the Union than an emotional case for maintaining the ties that bind. And it was none the worse for that. There is something thin-blooded about an argument for independence that rests, at least in part, on the cartoon-villainy of George Osborne and the hated so-called bedroom tax. As unpalatable as these things may be (you mileage may vary) they are temporary inconveniences. These things too shall pass.

Independence is forever, not just for this parliament. Hence too the audacious attempt to convince Scots that there is no difference between the Labour and Conservative parties. Ed Miliband? A Tory in all but name, don’t you know?

That’s not the only piece of nationalist sophistry we must endure hearing repeated time and time again. There is the notion that Scotland will remain British even after independence because, gosh, British is simply a geographical description. Alex Salmond, who should know better, and plenty of nationalist bloggers (who don’t) endlessly repeat this as though it were something other than a primary school level debating point.

But by that rational the citizens of the Irish Republic are also British since they inhabit part of the British isles. In my experience this label is one the Irish reject even though, for sure, they are plainly a part of a shared historical, cultural and political entity that reaches east-west as well as north-south.

Deerin’s article was, as you would expect, sneered at and mocked by many of the usual suspects. Lacking any sense of Britishness themselves, there is a breed of Scottish nationalist who finds it impossible to imagine why anyone else might think differently. That’s their prerogative. It’s a prerogative that makes it harder for them to persuade their countrymen to endorse an independent future, however.

Be that as it may, one of the curious features of this referendum campaign is the manner in which those campaigning for independence insist they reject so-called identity politics while those keenest on preserving the Union are equally reticent to wrap themselves in a flag.

Nicola Sturgeon, for example, argues:

 “I don’t think the independence referendum is really about identity. This is a decision about where power best lies. I don’t think we should or require to attack the British identity – it is absolutely compatible for someone to feel a sense of British identity but still support Scottish independence.”

This is all very post-modern. Or post-something anyway. A nation state isn’t a matter of identity or shared experience, merely a technocratic demarcation of power. (In which case: independence for the Borderlands please. Berwick irridenta and all that.)

This is hooey. Or, actually, Tartan Cute Hoorism. It is the idea that independence answers all problems at no cost whatsoever. You can be British and still think the British state as we know it should be consigned to the scrapheap and this won’t change the way you think about yourself or your country at all.

It’s a good line but it’s not one, I think, many nationalists really believe. Not in the deepest recesses of their hearts, not really. But it also reveals, perhaps unwittingly, the power of, yes, Britishness.

If Britishness – and indeed the British state – were so hopelessly sclerotic or stale or otherwise useless there’d be no need to pay it this kind of oblique tribute. When Alex Salmond talks about the social union that would survive intact long after independence he acknowledges that Britain and Britishness are ideas or concepts or facts or layers of identity with which many Scots are not only comfortable but actually, if quietly, proud. They are not ashamed to be Britons.

In other words, Britishness is worth something and, even according to the nationalists, some form of Britishness is something worth preserving. You never, I think, heard Eamon de Valera talk like this.

Granted, Scotland and Ireland are, though alike, also different. But that’s the point too. There is no Caledonian grievance to which the only acceptable solution is independence. Even the SNP don’t – at least not in the leadership’s public pronouncements – reject Britain. On the contrary, they insist it will survive and not just as a geographical entity.

On the one hand this reduces the “risk” of independence (we’ll all still be chums and we’ll never be truly foreign to one another); on the other it also reveals a certain emptiness at the heart of the SNP’s technocratic vision of independence. Is this what it is all for or really about? Is that it?

You don’t have to choose – unless you want to – between being Scottish and British. Not at the moment anyway. The SNP leadership would have you believe you won’t need to choose between being Scottish and British after independence either. Because, they insist, this isn’t an argument about identity at all.

But if a nation state is not about an identity or an idea or a shared sense of belonging then what is it? Perhaps an independent Scotland would be a new kind of state. A virtual state of some kind, shorn of identity or shared values?

Of course that’s not what the SNP really think at all. If it was they would spend less time banging on about Scottish values and complaining that said values are being assaulted by the Westminster government. So we are different after all. Except when we are not. Because we will still be British and you need never feel that your attachment to Britishness is threatened by leaving the Union because the Union, in its essentials, will remain. Everything will change but nothing will change.

Somewhere this must make sense but it doesn’t make sense here. If you leave a state you don’t remain a part of that state. There may be ample reason to set sail on HMS Independence but you can’t set sail and remain in port.

Of course the referendum is about identity. If it weren’t we wouldn’t be having the damn thing.