MODERN Scottish nationalism was born in the pages of the New Left Review (NLR), sometime in the mid-1960s.

That’s the bold claim at the heart of Ben Jackson’s excellent new book, which traces the intellectual origins of contemporary nationalist politics through the work of writers like Tom Nairn, Neal Ascherson, George Kerevan, Isobel Lindsay, and my own late dad, Stephen Maxwell.

In the immediate pre- and post-war periods, the SNP were a provincial, conservative organisation.

Its leaders – Tom Gibson, Robert Macintyre, Donald Young – rejected the ideological labels of “left” and “right” and wanted Scotland to become an independent “mother nation” of the British Empire, on an equal constitutional and colonial footing with England.

But that changed when a younger generation of thinkers emerged who, Jackson says, sought to reshape the nationalist movement for more radical ends.

The influence of Nairn, a brilliant Marxist academic from Fife, was central.

Writing alongside his English colleague Perry Anderson in the NLR, Nairn argued that the British political system was frozen in time; anchored to an archaic doctrine of absolute parliamentary sovereignty and resistant to any prospect of democratic reform.

Westminster needed to be shocked out of its elitist slumber – and the only way to do that was by breaking the UK up into its constituent parts.

According to Jackson, the Nairn/Anderson thesis, as it came to be known, was pivotal to Scottish political thinking in the 1970s.

In short-lived but influential journals like Cencrastus and Question Magazine, in books like The Radical Approach and Gordon Brown’s Red Paper, and in vibrant breakaway factions like the 79 Group and Jim Sillars’s Scottish Labour Party (SLP), activists thrashed out the merits of independence versus devolution, national sovereignty versus global economic integration, and local versus central state control.

What emerged were the basic contours of the nationalist world view, still visible in the rhetoric – if not necessarily the policies – of SNP politicians today.

The sociologist Isobel Lindsay made the case for constitutional gradualism and cross-party coalition building.

The journalist Neal Ascherson urged the SNP to embrace radical forms of popular democracy, rooted in Scotland’s Enlightenment traditions.

George Kerevan, at one stage a Trotskyite member of the SLP, called for an alliance between Scotland’s progressive middle classes and other marginalised groups.

And my dad, then a senior nationalist strategist, said the SNP should work replace to replace Labour as the dominant party of the Scottish centre-left.

These ideas have framed the trajectory of nationalist politics under both Alex Salmond and Nicola Sturgeon, Jackson argues.

Over the past 30 years, the SNP have promoted devolution as a stepping-stone towards independence; it has stressed the practical, democratic benefits of self-government; it has relentlessly opposed the Tories at Westminster; and it has all but destroyed Labour as a serious political force north of the Border.

Jackson avoids the clichés of nationalist history. Rather than revisit the conventional flashpoints of the SNP’s electoral development – Hamilton and Govan, Billy Wolfe and Winnie Ewing, 1979 and 1997 – he examines the meta-narratives that have given the movement its power.

The notion of independence as an escape route from Britain’s long-term crisis and decline, for instance, is a core feature of the SNP’s anti-Brexit pitch.

But it was first articulated by Nairn more than 50 years ago and became a key part of the party’s highly effective propaganda campaigns of the 1970s and 80s, which contrasted the relative bleakness of Britain’s economic landscape with the oil-fired wealth a prospective independent Scottish state.

Thatcherism was a breaking point, Jackson says.

The experience of Tory-imposed deindustrialisation not only furnished independence campaigners with a potent myth of national oppression, it bolstered the left’s rationale for leaving the UK.

That rationale became overwhelming for many Scottish voters – particularly Scottish Labour voters – in 2014, when the SNP cast independence as the last line of defence for Scotland’s NHS.

There are no huge revelations in The Case For Scottish Independence; Jackson’s analysis won’t be all that new to anyone familiar with the source material.

Nonetheless, the book threads together the overarching themes and beliefs of the modern SNP with incredible clarity and detail.

Nationalism’s strength ultimately lies in its pragmatism, he concludes.

When the mainstream of British and European social democracy moved to the centre, the SNP moved with it.

When “hard” forms of independence failed to win the support of the Scottish public, the party altered its vision of what sovereignty meant in the 21st century.

“Scottish autonomy [is now] conceptualised as an open-ended process,” Jackson writes. “This was the major victory of the gradualist position within the SNP.”

READ MORE: History of the Scottish independence movement: The SNP

THE Case For Scottish Independence struck me on a personal level, too.

Jackson notes how my dad’s view of Scottish nationalism shifted profoundly over the decades.

In the early 1980s, as a founding member of the 79 Group, he had seen independence as a socially transformative project.

By the time he died in 2012, he was much more circumspect about what he thought independence could achieve.

Scotland might get better governments, a written constitution, and elected representatives slightly less hostile to progressive policy ideas, but there would be no dramatic resurgence of class politics, no deep change in the structures of financial and economic power.

As Jackson expertly shows, that shift tracks with the SNP’s political evolution over the past half-century – the party has been on a long, turbulent journey from the New Left Marxism of Tom Nairn to the hard-headed realism of Nicola Sturgeon.

But then, much like devolution, independence isn’t a simple concept with a single, binary definition.

It’s a painstaking process of constitutional advance and retreat.

Likewise, Sturgeon’s gradualism isn’t new, either. It stems from the formative decades of the 1960s and 70s – decades that made Scottish nationalism what it is today.

The question now is whether the national movement is capable of adapting again to the new challenges it faces: Covid, the climate crisis, the authoritarian populism of Boris Johnson and Dominic Cummings.

We may well find out in the next few months.

The Case For Scottish Independence: A History of Nationalist Political Thought In Modern Scotland by Ben Jackson, Cambridge University Press. Sunday National readers can benefit from a special 20% discount by visiting www.cambridge.org and entering the code JACKSON20 at the check-out