The bit about the Stone of Destiny story I like the most is when the gang of thieves, or liberators, were manhandling the stone out of Westminster Abbey and managed to drop it and break it in two. It adds an element of farce to the story doesn’t it and what British, or Scottish, political story would be complete without an element of farce?

As for the actual motive of the four people who pulled off the plot, I have to say I’ve never really got my head round that one even though I got the chance to discuss it directly with one of them, Ian Hamilton. It seemed to me that the last surviving member of the gang, before his death this week, had a reassuringly nuanced approach to the whole thing. He was in his 90s; he’d had plenty of time to think about it.

One of the main things Mr Hamilton said was that icons matter – why else would he and his comrades have gone to all that bother over a lump of sandstone? But he also said that people had become ridiculously obsessed with the subject over the years. In fact, he was pretty grumpy about the fact that all people ever wanted to talk to him about was that wretched stone.

His explanation for the fuss was that people, particularly young, excitable nationalists like he was in the 1950s, get distracted by the drama and theatre of the stone and there was certainly plenty of it. Hiding out in the Abbey. Road blocks at the Scottish border. Its dramatic reappearance on the high altar of Arbroath Abbey complete with a letter addressed to the King calling on self-government for Scotland. It’s a great story.

In that sense, the removal of the stone worked: suddenly, Scottish politics and self-government was being talked about much more. The writer and devolutionist Nigel Tranter said at the time that the theft of the stone might appear foolish and childish on the surface but that it would have the effect down south of focusing attention on Scotland’s complaints.

However, in the end, the hard lesson of the story is that it doesn’t really work that way and Mr Hamilton was pretty clear about that when I spoke to him. He reminded me of just what a low ebb Scottish nationalism was at when they took the stone – indeed, he wasn’t even a member of the SNP. “All they did in those days was sing songs about Bonnie Prince Charlie,” he said.

His bigger point was that, even though a lot has changed since the 50s, even though the SNP became the dominant party, the change was still not great enough. No matter how many votes there are for nationalist parties, he said, “the people who run the UK will not see us go.”

This, in a way, is the hard lesson we can learn from Mr Hamilton’s experience as a star of the early movement who went on to live through (possibly) its highest point. The people who run the UK, as he put it, will not see us go, but perhaps a better way of putting it is that the test for independence and breaking up a union is, and should be, very high indeed and that test has not been met yet.

If you’re a supporter of independence on the other hand, what’s striking about the Stone of Destiny story is how much, despite Mr Hamilton’s pessimism, the mood and the language has changed since the 50s. Looking through the press coverage of the time, it’s striking how old-fashioned and weird it sounds. The dean of the abbey talks about “wild” Scotsmen threatening to steal the stone. The newspapers were also unanimous in their criticism of the gang – we must not call them heroes, they said.

But really, that’s what they were, even to someone like me who would prefer to stay in the union. A hero is someone who has courage to do something many of us wouldn’t and that’s what Mr Hamilton and his friends did. They are still a long way from achieving independence, but 70 years after they dragged the stone to their little Ford Anglia, their cause has covered a much greater distance. Mr Hamilton would hate me for saying this but he contributed a great deal to that achievement. Icons work.

Read more by Mark Smith:

A prison encounter with the justice minister – and what we learned from it

Lessons from the life of a 47-year-old bird called Bob

Why doesn't the Scottish Government understand the island dimension?