I sat next to our local MSP at a dinner on Wednesday night. It was a fund-raiser for the upkeep of Dunkeld Cathedral, just across the river from where I live. The MSP happens to be John Swinney, Scotland’s Finance Secretary. He’s charming and modest, a man of deep conviction and, for all his high office, a good servant of his constituency. I couldn’t help wondering how often George Osborne’s constituents find themselves sitting next to their MP at local events.

We had the inevitable conversation, during which he seemed quietly confident that things are not as the pollsters portray them, citing the SNP landslide in 2011 as evidence of the fact that people often don’t reveal, or perhaps even know, their real intentions until polling day. He was certainly in the right place to make such an assertion: on that occasion the SNP took 61 per cent of the vote in our area.

He also spoke with satisfaction of the findings of the Fiscal Commission, the four wise men, including Nobel prize-winning economist Joseph Stiglitz, who have pronounced that by international standards Scotland is a wealthy and productive country, and that there’s no doubt it has the potential to be a successful independent nation.

Which is all very well if you’re happy to be relegated to the international standing of a country like Denmark, exposed to the vagaries of an economy one-tenth of the size of the UK’s, and susceptible to the internal divisions that may arise once the focus of opposition no longer lies across the Tweed. So run some of the counter-arguments. And so the debate will continue for the next 18 months.

I’m neither a politician nor an economist, and I know that each side will deploy the figures and arguments that best serve its cause. As one of the great uninformed, I tend to be swayed by the last convincing argument I’ve heard. But on this occasion, I find myself reacting on a more visceral level.

Perhaps it’s something hereditary: my great-great-uncle, RB Cunninghame Graham, about whom I’ve written before, was a Scottish laird of ancient lineage who first, along with Keir Hardie, pioneered socialism in Britain and was a founder of the British Labour Party; then became President of the Scottish Home Rule Association, in 1928, and finally Honorary President of the Scottish National Party, when it was formed in 1934.

His views at the time included the notion that Scotland is “a distinctive nation” which suffers from being “a mere appendage to the predominant partner.” “We want a renaissance,” he went on, “a re-birth of Scottish literature, art and sentiment. We can only induce these things by agitating for national self-government.”

Today he might have expressed it slightly differently, using terms such as ‘culture’ and ‘identity’. But this is the level on which I respond and, semantics aside, feel myself drawn by a momentous sense of possibility. While, like most Scots I know, I have absolutely no reason to hold anything against the ‘predominant partner’, I can’t ignore the fact that Scotland is a very different place to England in so many ways – economically, socially, culturally, internationally; and the chance for it to reassert that difference, freely and wholeheartedly, to walk in the world as a fully self-determining, sovereign nation seems to me to represent the greatest and most thrilling opportunity of our lifetimes.

Since returning to Scotland in 1990, I’ve been acutely aware of the bad story that continues to infect the Scottish psyche, the story of military defeat and occupation, of clearance and emigration, of poverty and dependency, of industrial decline and low economic output, of sectarianism, alcoholism, chronic bad health and sporting failure.

Of course, that story is less than half of it, and it’s only about the last 300 years, the period of political union. But for too long it has had a disproportionate hold on people. As someone who’s generally preoccupied with the power of stories, I can’t help thinking that independence would allow us to start telling a new story, in a way that would be profoundly energising, liberating and esteem-giving – with all the material benefits that would consequently flow. Certainly the idea that Scotland, alone of small countries in Europe, should be incapable of managing its own affairs, seems far-fetched.

I have no intention of following my great-great-uncle into politics, but perhaps what I have inherited is his romanticism; as well as being a politician he was also a dreamer, an adventurer and incurable champion of underdogs. As time goes on I realise that this for me is deeply, perhaps even irrationally, a matter of the heart. And I know I’m not alone. According to my dinner companion, even the normally imperturbable Deputy First Minister, Nicola Sturgeon, was ‘in pieces’ at the formal signing of the treaty which sets the referendum date, last week in Edinburgh.

Whatever one may think, this is an extraordinary moment in which to be living in Scotland. The world will be watching us.