Scotland doesn’t exist. The United States of America is a figment of our imagination. Russia is as real as the fake news that pours out on to the internet from within its fictional borders.

However real they might seem, nation states belong in the realm of ideas, not tangible things, and John Lennon’s Imagine had it the wrong way round.

OK, I admit if Theresa May, Boris Johnson or whoever was to send a distinctly real British Army Challenger tank on to my front lawn and invite me to reconsider the non-existence of the United Kingdom, I most definitely would, might even start singing Land of Hope and Glory. Or at least try to, it would quite quickly descend into mumbling what I’d be hoping sounded like the words.

But, thankfully, using the military to ensure the loyalty of its subjects runs counter to ideas about what the UK is all about. And ideas – such as, of course, nation states – can be powerful things. Good ideas have saved countless lives, just as bad ideas have ended them.

Being ideas, countries can change and are probably always doing so, albeit usually in subtle, small ways that are barely noticeable but become apparent as time marches on. Some politicians today talk about British or Scottish values. In my book, this is a “categorisation error” and I’d much rather we talked about “democratic values”, but whatever values are held today in Scotland or the UK, they are very different to Victorian ones.

There is no particular patch of planet Earth that must always be a liberal democracy – a haven of free speech, the rule of law and human rights – just as nowhere is eternally fated to languish in the grip of despotic rulers who think punishing people they don’t like with a lethal dose of nerve agent is a reasonable way to behave.

So it is really important to keep up the pressure on whatever nation you happen to inhabit to move towards the light of freedom and away from sinister ideas that seem to have been re-emerging from the shadows in recent years.

Here’s William McNeil, of the “hipster fascist” movement, Scotland for Generation Identity, attempting to explain to The Scotsman this week why his group did not promote a hateful, white supremacist ideology. “Anyone making this claim, intentionally or not, refuses to understand Identitarianism. It is not about skin colour, nor is it about anyone being better than another. All peoples have a right to preserve and promote their group identity in their homelands.”

In case you don’t know, Generation Identity’s leader in Austria, Martin Sellner, exchanged emails with and accepted a donation of €1,500 from Brendan Tarrant, the Australian charged over the murder of 51 people at two mosques in New Zealand in March. Sellner insists he doesn’t believe in violence, but clearly Tarrant was a fan.

There are no different human “peoples” or races, these are ideas entirely invented by racists. Tarrant killed people at random simply because they were Muslim just as Isis killed Salford taxi driver Alan Henning – despite the pleas of Islamic scholars to spare the life of someone who went to Syria to deliver aid. Both Isis and Tarrant bought into the idea that their victims were so defined by their religion or their nation that they could be killed for that reason alone.

For some self-described patriots, nationality plays just as strong a part in defining a human being as race does for racists or religion does for the most fanatical of religious bigots (it’s probably important to state at this point that the vast majority of religious people are not bigots at all).

In his short poem Patriot, the late Norman MacCaig – I first wrote that he was a “Scottish poet” but then decided to delete that bit – offered a different vision:

My only country

Is six feet high

And whether I love it or not

I’ll die

For its independence

The Person’s Republic of Ian Johnston wholeheartedly agrees and, however tall we are, most of us know we are an individual – insert the funny line from Monty Python’s Life of Brian here – even those prone to seeing others as nothing but the faceless members of some group of millions of people. Despite all this, I am happy to say that countries – even though they are just ideas – are very important. I’m also happy to pay my taxes and do all the things you are supposed to do as a citizen of the UK.

However, nations are important as a unit of democracy, perhaps the fundamental unit of democracy. They help human beings organise themselves into large groups in which their rights as individuals are protected. That’s what countries should do anyway. How big that group is, what territory it controls or who is a member should not be the main concern.

But medieval ideas about nation states still persist. In the not-so-good-old days, kings who led armies to conquer were heroes. Those who questioned their power too much were traitors whose heads would likely end up on a spike. With no genuinely legitimate claim to power – the hereditary principle not being one – loyalty had to be enforced on pain of death. This is still true in today’s tyrannies.

In countries that are liberal democracies, where individuals agree to put people into power, knowing they can be removed if necessary, strict penalties for treason are not necessary. As a criminal offence, it has all but died out in the UK. And yet, amid the passionate debates about Scottish independence and Brexit, bitter accusations of treason have been thrown about quite a lot. That, in my view, is a slippery slope that risks a slide through the mire towards the insanity of Isis, Generation Identity and the rest.

Individual human beings are real. Nations are not. They are ideas that we have made effectively real because we believe in them so much and because it is useful in a practical way. But, we must resist the temperation to believe in them too much or we will lose touch with reality.

Why it’s important to remember Scotland doesn’t actually exist – Ian Johnston