It's a canard of the contemporary constitutional debate that Scottish Nationalism is "civic" rather than "ethnic" in nature, having long ago jettisoned its less attractive elements.

This is generally accepted by most observers of the political scene and backed by the "modernist" school of political science. It's a nice idea, and of course a convenient one for the modern SNP, but it doesn't quite tell the full story.

In terms of positioning, the shift is strongly associated with Alex Salmond. "The SNP is engaged in the process of reinforcing our identity as a civic national party", he wrote in a Herald column 20 years ago, "appealing to all of the people of Scotland regardless of origin". It has, in certain respects, worked. At the most recent Holyrood election the SNP attracted a sizeable chunk of the Catholic and Asian vote, while just last week the Polish actor Tomek Borkowy backed the Yes campaign. "Scotland gave us [Poles] an opportunity," he explained, 'and we will repay our debt".

Although these developments are positive, in reality modern Scottish Nationalism is neither wholly ethnic nor wholly civic, but rather a mixture of the two. This is clear to anyone who regularly attends Nationalist gatherings. Although conferences are tamer affairs (they often resembled clan gatherings in the 1970s), last September's pro-independence rally on Calton Hill was ostentatiously ethnic, with a plethora of kilts, face paint, frayed banners and unsavoury characters from fringe European secessionist movements (this year's event has been quietly shelved).

Kicking off the SNP conference on Friday, the First Minister revived an old battle cry when he told delegates the SNP's aim had always been "the freedom and independence of our country"; but the deployment of the word freedom was hardly consistent with his 2012 statement that Scotland was "not oppressed" and had "no need to be liberated".

Mr Salmond's recent speech at Glasgow Caledonian University's New York City campus was a case in point: Scots, he said, would vote "based entirely on consensual, civic, non-ethnic and peaceful principles", but he earlier referenced US citizens claiming Scots "ancestry", the Declaration of Arbroath (twice), statues of Robert Burns and Sir Walter Scott in Central Park and the "end of an auld sang" in 1707; all standard reference points for Nationalism of the non-civic variety.

The same goes for recent Scottish Government policy. As a 2012 survey of SNP policy documents and speeches by the academic Andrew Mycock demonstrated, the party's shift from ethnic-based nationalism had "not been absolute", with its framing of modern Scottish Nationalism drawing heavily on historical imagery that "explicitly recognizes the ethnicized foundations of the Scottish nation and state".

SNP ministers, for example, had sought to "embed Scottish history, culture and heritage" in a range of policy areas, while "indigenous" languages such as Gaelic and Scots (previously "suppressed and oppressed") had been promoted. This year's Homecoming will again invite "blood Scots" to return to the mother country and, strikingly, the First Minister's Holyrood office is dominated by a painting featuring a massive Saltire. Talk of Scottish "values" is generally more inclusive but it still hints at an ethnic set of cultural (even moral) values that, of course, differ (usually in unspecified ways) from the "English" variety. This is a clever repackaging of cruder anti-Englishness and one Unionist parties such as Labour have been willing since the 1980s to buy into.

There are elements in the wider National Movement, such as the writers Alasdair Gray and Alan Bissett, who are more explicit about their ethnic nationalism, but it's not as if they've been kept at arm's length by the SNP. Until recently Gray was much cited by the party leadership, while Bissett was given a prominent slot before Mr Salmond's keynote address at the Aberdeen spring conference on Saturday. This was a preview of Bissett's forthcoming Fringe play The Pure, The Dead and the Brilliant, which, he hopes, will become "the statement about independence" during the August festival. If I were the SNP I'd be rather concerned about that for, although talented, Bissett is on the "Scotland was colonised" wing of the Yes campaign and his black-and-white view of Scottish history has found pungent expression in the play. Delegates, intriguingly, gave it a standing ovation.

The latest edition of Political Quarterly includes a penetrating piece of analysis on the political thought of Scottish Nationalism by the historian Ben Jackson that further deconstructs modern SNP thinking. He analyses the shift from independence predicated on defending "a threatened ancestral culture" to a campaign for Scottish statehood "not so much about the expression of a national identity as an instrumental device for the realisation of a more egalitarian society".

That, of course, is the stated aim, although Dr Jackson concludes it has essentially become what Tom Nairn disdained as "Labourism", a gradual pursuit of social reform bound by conventional parliamentary and neoliberal orthodoxies. Nairn's lasting influence is most notable in how Nationalists view, and arguably caricature, the British state; Mr Salmond's reference to the UK's "fading imperial grandeur" in the US last week was pure Nairnism.

But, as Dr Jackson notes, such Nationalism does not really "offer a straightforward escape route from the power now wielded by finance in contemporary capitalism". Its planned retention of British institutions such as the monarchy and Bank of England would, ironically, leave an independent Scotland "under the dominion of some of the very antiquated 'imperial' structures they excoriate".

Another canard of modern Scottish Nationalism is that, while the Labour Party has ditched its principles and swung to the right, the SNP has remained consistent since its formation in 1934, thus Nicola Sturgeon's conference invitation to Labour voters to "reclaim" their party by voting Yes in September. Not only is this a bizarre reading of the party's history but it neglects, of course, the SNP's own shift to the right (in economic terms), which roughly mirrored that of Labour.

But the pitch is clear: Labour voters are vital to a majority Yes vote, so the wooing continues. Therefore independence, claimed Mr Salmond in his speech, is not about him (despite Ms Sturgeon introducing him as the "man who's led Scotland to this moment"); nor the SNP (despite Salmond saying independence would "fulfil … the aims and the efforts of the party over these 80 years"); nor even the wider Yes campaign (despite Better Together being dismissed as "totally laughable and completely ludicrous").

One can imagine the SNP's derision were Nigel Farage to claim that his campaign to extract the UK from the EU wasn't about him, Ukip or the wider Eurosceptic movement, for British Unionism is also a blend of ethnic and civic nationalism although it, by and large, does not attempt to occupy the moral high ground.