Ahead of the EU referendum on 23 June, I've been looking at the relationship Scotland has with Europe and what implications there could be north of the border if the UK ends its membership.
How European are we in Scotland, out here on the North Western margin of the continent?
The last time the UK voted on membership of what was then the European Community, Scotland was pretty sceptical.
The majority for staying in was lower here than anywhere else in the United Kingdom except Northern Ireland.
Now, according to the opinion polls, Scotland is second only to Northern Ireland in its enthusiasm for the EU.
Former Labour MP Tom Harris, who leads the Leave Campaign in Scotland, said: "Support for the EU is widespread in Scotland - but it's not very deep.
"The campaign to leave the EU is seen very much as a Conservative Party project, and in Scotland there are an awful lot of people who will say 'Well, if the Tories want this, I don't'."
But that shift in public opinion over the last four decades walks hand-in-hand with the decline in fortunes of the two political parties who dominated Scottish life in the 1970s - the Conservatives and Labour.
In the 1980s, the Scottish National Party, which had a history of opposition to EU membership, changed too.
Shortly after a young activist called Nicola Sturgeon joined the party at the age of 16, the SNP adopted a new position - Independence in Europe.
This sold to a still sceptical Scottish electorate a new conception of what independence would mean: not separation but partnership in a new, broader community of nations; an independent Scotland would not be "going it alone" any more than, say, Denmark was "going it alone".
And so the standing of both the SNP and the EU in Scottish public opinion began a long and, until now, steady climb.
It is the second time in as many years that Scotland has been asked to make a decision about what kind of country it wants to be.
But this time, the UK will decide whether we stay in the EU or leave.
And Scotland will have just an 8% say in that decision.
The possibility that Scotland will vote to stay in, while the UK as a whole votes to leave, is far from remote. It is real.
What would it mean?
Many on the Remain side - from Alex Salmond to William Hague - have warned that it would push Scotland further down the road to independence; that if Britain leaves Europe, Scotland will soon enough leave Britain.
Scotland's First Minister Nicola Sturgeon told me: "I'm not keen to speculate about that at this stage - for the simple reason that I hope the situation won't arise.
"I want Scotland to be independent but I wouldn't choose to have another referendum [on independence] on the basis that the rest of the UK had chosen to do something damaging for the rest of the UK."
Her caution is now familiar. She knows she cannot risk losing a second time. And were the UK to vote to leave the EU, the independence proposition changes.
The argument that an independent Scotland would be able to share the pound sterling with the rest of the UK seemed implausible to a majority of voters last time round - and that was a scenario in which both would be inside the EU.
Professor James Mitchell of Edinburgh University said the situation was "difficult enough" in 2014, when the Scottish independence referendum was held.
He added: "The idea of trying to sell the message of Scottish independence on the currency issue, in the context of Brexit, would be very, very difficult."
I asked Nicola Sturgeon whether the pro-independence case would need a new currency plan to replace the one that had failed to persuade a majority in 2014.
She said: "Before I say what I'm about to say this is not me saying that our position on the currency was wrong, because I don't think it was.
"But clearly that was one of a number of areas where we did not persuade enough people that what we were saying was as credible as it needed to be.
"So when you don't win a campaign it would be incredibly arrogant to assume that there was nothing more you had to do to persuade people in the future."
Does that mean that next time round the SNP will need a new currency plan, or simply to be more persuasive?
On that, cautiously, she repeated that she would not be drawn into speculating about something she did not want to happen.
It is striking how little high-profile support there is for Brexit in Scotland.
Who is Scotland's Boris Johnson, Iain Duncan Smith, Michael Gove?
Who, for that matter, is Scotland's Nigel Farage?
In the Scottish Parliament last week all five party leaders spoke out for the campaign to Remain.
During a debate in the Holyrood chamber last week, only eight of the 129 MSPs voted to leave the EU.
Would there be a question of political legitimacy if, as Nicola Sturgeon puts it, Scotland was "dragged out" of the EU against its will?
'It's not about Scottish independence'
I asked Tom Harris.
"No," he said bluntly.
"There would be no legitimacy question. We are voting as part of the United Kingdom. Each person's vote counts equally.
"I think it's really important that Scots approach June 23 with one question in their mind, which is 'should we continue to be members of the EU?' That's the only question that's being asked. It's not about Scottish independence.
"If we come out of the EU, then all the powers that the European Commission and the European Parliament have over Britain have to go somewhere.
"Some of them will go to Westminster, but some would come to Holyrood. We would no longer be in the Common Agricultural Policy and the Common Fisheries Policy. Those powers would be handed to ministers at Holyrood."
And they would be SNP ministers.
I asked Nicola Sturgeon why, when the repatriation of political power was the defining purpose of her political life, she wouldn't want to bring power back from Brussels, as well as London.
She explained: "I want Scotland to be independent, so the choices about when, and in what circumstances, we pool our sovereignty are our choices to make.
"But I want an independent Scotland to be an outward-looking, international country playing its part in the world, joining with other countries to deal with the big challenges the world faces and in the European Union, imperfect though it is, it's better to be in there."
A Brexit vote would change Britain's relationship with its European neighbours in ways that would not be clear until it happens.
But it would also further change Scotland's relationship with its single most important neighbour - the one it's connected to not by the sea but by land and history.
Would it propel Scotland further down the road to independence?
It certainly changes the independence proposition, raises new questions about what independence in those circumstances would look like, questions we've barely even begun to consider, and which even Nicola Sturgeon says bluntly she is not ready to speculate about.
And it could confront Scotland with a new national question: which Union do you want to be in, the British one or the European one?
And that's an argument the country hasn't even begun to have with itself.