England, in many ways, remains a mystery to me.

I say "remains" for beyond London - where I've spent nearly half the past decade - and perhaps Manchester, whole swathes of the UK's largest "nation" are unknown to me.

I've made a point of rectifying this recently. I spent Easter Saturday roaming Salisbury and Wiltshire's Chalke Valley with a native, while yesterday I visited Norwich for the first time, a fine cathedral city with an eclectic mix of 1960s brutalism and medieval untidiness.

Otherwise my acquaintance with Englandshire is limited to the East Coast Main Line, the metal artery connecting the 1707 Union's two capitals. The relative tedium of rolling fields and the occasional Anglican spire is only broken as you reach Durham, when its Norman cathedral bursts into view.

I guess you could say I'm an Anglophile, something I have in common with the First Minister, although I've never been terribly convinced he has much understanding of the English psyche. But then, his experience is even more limited than mine: sleepers or flights to London and 23 years in the Westminster village.

To use Alex Salmond's own terminology, last Wednesday he embarked on a "day trip" to Carlisle in order to reassure England - or rather northern England - that even after independence they would "remain Scotland's closest friends, as well as our closest neighbours".

As ever it was a nice, pithy line that masked a multitude of contradictions. Announcing a "feasibility study" into a high-speed rail line from Scotland to England and a "borderlands economic forum" (assuming Scotland votes Yes), Salmond said Cumbria had "nothing to lose, and much to gain, from the establishment of a successful independent Scotland".

This was disingenuous on a number of levels. Not only did talk of a "borderlands" initiative tacitly concede independence would create more difficulties than exist at present, but there was no mention of less attractive consequences such as continuing to charge English students tuition fees (in contravention of EU rules). If he'd made the same speech in Newcastle then he'd no doubt have been reminded of the time he lured Amazon - on the cusp of creating much-needed jobs in that part of England - further north with a £1.8 million sweetener.

If Scotland could manage that under devolution, runs the justified fear, what sort of impact would an independent country with a lower rate of corporation tax have on northern England?

Other elements of last week's St George's Day Declaration were familiar claims that independence would stimulate constitutional change in the rest of the UK while changing the "centre of economic gravity of these islands" to the North's advantage, although he didn't really explain how: one assumes the wealth generated by an independent Scotland will, to borrow another phrase, "trickle down" to England.

As ever, there are voices on the left willing to lend such woolly arguments a veneer of intellectual credibility. On BBC Scotland last week Tariq Ali, like Noam Chomsky a recent convert to independence, said a Yes vote would "open England up", a theory echoed by the singer Billy Bragg in a piece for The Guardian, but they all, particularly Salmond, seem blissfully unaware that it's already happening.

Recent surveys indicate not only an increasing sense of "Englishness" but also growing support for regional devolution. Ed Miliband recently promised (if he becomes Prime Minister) to decentralise on the basis of "city regions", building on the successful micro-economy already created around Manchester. Admittedly it's slow and incremental, but nevertheless there is movement.

Talking of the Labour leader, I watched him in Motherwell on Friday politely contradicting an English "stereotype" propagated by some supporters of independence. "Don't believe this idea," he cautioned, "that there is a Tory England in contrast to a progressive Scotland." As Mr Miliband pointed out, voters in England last elected a majority Conservative government (and not by much) 22 years ago.

And although these days Mr Salmond oozes warm words about the English, three years ago - in the hubristic wake of election victory - he told one London-based journalist that although England and Scotland shared the same language "you couldn't get two more different cultures", while in 1999 he claimed Britishness had been co-opted by thugs and racists while Englishness was an "aristocratic, almost mediaeval concept".

But then Mr Salmond is prone, on occasion, to say odd things. Take his forthcoming interview in GQ magazine in which he praises "certain aspects" of Vladimir Putin, particularly his restoration of "a substantial part of Russian pride" which, he added, "must be a good thing". The First Minister also conceded that the very English Ukip leader, Nigel Farage, possessed a "certain bonhomie".

It betrayed an admiration for aggressively anti-establishment - and, of course, nationalist - figures, which doesn't really sit well with the ecumenical "Scottishness" fashioned since he became SNP leader. It also glosses over the fact "Britishness" was the original flexible, multi-layered national identity, preceding modern "civic" Scottish nationalism by several centuries.

Instead, there's an unfortunate proclivity to generalise and caricature. In a recent pro-independence tract, for example, the columnist and former SNP candidate George Kerevan declared contemporary Britain has failed to forge a post-imperial national identity and was instead prone to "Little Englander racism".

Indeed, this conceit of Scotland as somehow immigration-friendly while Westminster and English public opinion, to quote Mr Kerevan again, opposes immigration "to the point of being racist", is most egregious. Not only has England - and particularly London - experienced levels of immigration far in advance of Scotland, cities like Birmingham and London (where a majority of the population is now from outside the UK) are testament to largely successful integration.

This, of course, doesn't conveniently fit into a pro-independence argument predicated upon a view of a "broken" UK and two nations (Scotland and England) with increasingly divergent sets of values, a narrative that will soon be ramped up assuming - as polls suggest - Ukip wins the greatest number of MEPs in England and the SNP wins in Scotland.

As someone who has lived in Scotland, Wales and England, I have never felt among people with fundamentally different "values". I've more often been struck by differences of class or background, but of course they exist as much within Scotland as they do between the nations and regions of the UK.

It is true, as an Irish colleague put it to me recently, that Scots in England (like the Irish) are often subject to what he called "benign condescension", but that isn't really a compelling argument for Scottish independence, and nor is the affinity I feel with the English, Welsh and Northern Irish a particularly good argument against it. Affinity can easily transcend national boundaries.

On Thursday, the 1707 Union will mark its 307th birthday, although neither Unionist nor Nationalist is likely to be celebrating. Caricaturing the two halves of that Union, meanwhile, might be necessary to ensure its demise, but it's hardly conducive to friendly relations either now - or, should there be a Yes vote, in future.