Last week I spent a few days on the Faroe Islands, a Danish archipelago to the north west of Shetland.

In fact, it looked a bit like the Northern Isles; the same tree-less, rugged beauty. And it wasn't just the landscape that seemed familiar - so did the politics.

The Faroes have had "Home Rule" since 1948, introduced as a compromise following a narrowly won independence referendum two years before. To this day, public opinion is split roughly fifty/fifty, though its salience as a political issue fluctuates; at present the constitution simply isn't a hot topic.

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And as in Scotland, within both camps - also known as "Unionist" and "Nationalist" - there exist a range of views. Of those favouring independence, for example, some want an immediate UDI (unilateral declaration of independence) while others believed it should be achieved gradually. Many Unionists, meanwhile, desire a steady increase in autonomy.

Readers of a certain vintage will remember when this same fundamentalist/gradualist split characterised the Scottish National Party, as it had to some extent since the party's formation in 1934. It was never a tidy division: some traditionalists were gradualists, for example, while many on the left of the party were fundamentalist in outlook.

Nevertheless the central argument over strategy dominated and was only largely resolved in 1997 (when the SNP agreed to campaign for a yes/yes vote in that year's devolution referendum) and fully in 2000 (when it backed a referendum as the means of achieving independence). For despite energetic attempts to rewrite history, the two parties formally opposed to devolution until the late 1990s were the Scottish Conservatives and SNP.

Alex Salmond, however, was always quite explicit in saying he viewed a devolved Scottish Parliament as a stepping stone on the "gradualist" path to full sovereignty, and while today that is the orthodox Nationalist view, for much of his first decade as leader it was not. In fact Salmond's attempts to nudge his party in a more devolutionary direction was often greeted with fierce resistance.

All of this is fresh in my mind as I've been working on a new edition of my biography (unauthorised!) of the former First Minister, "Against the Odds", which was last published in 2011. Obviously quite a lot has happened since, not least a sea change in the SNP's constitutional strategy. Indeed, between 2000 and last year's referendum "gradualism" reigned supreme, with murmurs of fundamentalist dissent (usually from Jim Sillars) regarded as eccentric voices in the wilderness.

Interestingly, however, there are signs that that old division is re-emerging, albeit in a very different form. Both sides agree another referendum is an absolute pre-requisite for independence (although for a few days post-referendum Mr Salmond appeared to toy with the idea of some sort of UDI), but there's a disagreement when it comes to timing.

Ironically, the former First Minister - who spent his early career battling the fundamentalists in his party - is now emerging as leader of the camp that believes another referendum should occur sooner rather than later; many are convinced, for example, that he was the "senior SNP source" who told journalists as much on the House of Commons Terrace a few weeks ago.

Their thinking runs as follows: now is as good as it's likely to get (i.e. 60 per cent support for the SNP), Nicola Sturgeon is riding high, Unionist are laid low, while another pro-independence campaign would be in much better financial and spiritual shape than Better Together Mark II.

Naturally, a majority Tory government at Westminster is also a useful backdrop, thus this camp wants the SNP to seek a mandate for a new referendum at next year's Holyrood elections, i.e. ensure the manifesto includes an unequivocal commitment to that effect. In other words, they're impatient, and it's not just old-timers who fear they won't live to see another referendum, but many new members who are still smarting from last year's defeat.

They also worry that further devolution - i.e. the Scotland Bill, which today begins its Committee Stage in the House of Commons - might weaken the party, possibly by compelling it to increase taxes once it has the power to do so (or rather greater power to do so) next April; in other words, as I explored in last week's column, make difficult decisions that potentially lose support from middle-class Scots.

Craig Murray, the former British diplomat who the SNP rejected as a candidate before the election, recently articulated this New Fundamentalism in a blog post. Gradualism, he argued, "has had its day", while he urged his party to commit to another independence referendum "before 2020". He acknowledged the arguments against, but reasoned that with a right-wing Tory government at Westminster and an incredibly popular SNP in Scotland, "there can never be a more favourable conjunction. If not now, when?"

The new gradualist wing, meanwhile, rejects this analysis, countering that another referendum should only be held when the Yes camp is certain to win (for example when polls show 60 per cent support for independence), and that moving too soon might backfire and worse, if defeated, kill the dream for a generation or more. This is, broadly speaking, the view of the First Minister, who recently reiterated that a second plebiscite is not on the "immediate horizon".

Nicola Sturgeon has also made it perfectly clear that there would need to be a "material change" in political circumstances, suggesting that a differential Scottish/English vote in the EU referendum might constitute such a change. That, however, is a red herring, for many of the new fundamentalists don't believe the result of that will be anything other than a majority "Yes" to the UK remaining part of the Brussels club.

And just as many fundamentalists in the 1990s suspected Mr Salmond was a closet devolutionist, a few of the new fundamentalists believe Ms Sturgeon might end up getting rather too comfortable as leader of an increasingly powerful devolved Scottish Government, leading to a further loss of urgency when it comes to another vote on independence.

That's an exaggeration, for there's chatter to the effect that the First Minister is keen on the idea of making the next Scottish Parliamentary term three years long (something soon to be under her control), enabling her to fight the next two Holyrood elections against the backdrop of a Conservative government.

And it also ought to be remembered that Ms Sturgeon, like her predecessor, has rather shamelessly ditched the line - repeated ad nauseam during the referendum campaign - that 18 September 2014 was a "once-in-a-generation" opportunity (she even defined a "generation" as 15 years). In other words, the First Minister hasn't ruled out another ballot sooner rather than later, it's just that she doesn't share the new fundamentalists' sense of urgency.

By her own admission, the current SNP leader is a cautious operator, and caution is most likely the best approach to the question of a second referendum. And the new fundamentalist/gradualist divide, at least at the moment, is a small one, although it'll take all the First Minister's skills to prevent it getting larger in the months ahead.