THERE is plenty of talk right now about the benefits of independence, but the most powerful arguments are romantic ones.

I don't mean that negatively, necessarily – just that they tend, rather than offering certainties, to engage my optimistic side, the inner dreamer who will risk a leap of faith. "Imagination is the key to creating a better nation," says pro-independence artists' group, the National Collective. Even at its least starry-eyed, the Yes campaign is asking me to opt for the lesser of two evils: the devil I don't know stands a chance of being preferable to the one I do.

A lot of people are uncomfortable about being asked to dream, and imagine, and leap. Increasingly, however – especially with the No campaign peddling Union Flags and fear-mongering about the need for a strong defence sector – I find myself drawn to the Yes brigade's investment in potential; positivity; future-focused thinking rather than caution and conservatism. In terms of the arts, I see, in theory, how a small nation unencumbered by creaky Westminster bureaucracy might be nimbler – in terms, for example, of engaging with new cultural economies and new technology. How it might be poised to celebrate its traditions, but also embrace more radical new movements.

There are strong precedents, after all, for fresh cultural dawns following the casting off of colonial trappings. Whatever political complexities India, Ireland and Jamaica have faced since severance from Britain, their indigenous cultures have asserted themselves powerfully, both with art that specifically addresses the legacy of colonisation, and that which reaches back before it, or seeks a new identity beyond it. Even those on the fence about independence, or opposed to it because of economic trepidation or fear of isolation, might be attracted by the potential strengthening of Scottish cultural output.

But after we fantasise about the post-independence surge of confidence, questions rush in. Could we afford this fabulous flourishing? Could we support an independent domestic media to talk about it? And what about the wider world? Would it still hear about us if our status altered, and our communication, support and promotion structures changed with it?

Then there's the more nebulous question of what a freed-up culture would concern itself with. When your culture bases part of its self-image on its relationship to a dominant neighbour – when much of its identity has been constructed specifically in opposition, in defiance – what will it look like on its own? We hear frequently about Scottish culture being dogged by negativity and self-criticism, and certainly that moan – a moan about moaning! – might resonate with anyone who works in the arts.

It is part of the mindset that obsessively criticises Scottish cultural endeavours, then asks in the next breath why Scotland isn't more valued in the world. It's there among people who notice the quality of an artwork only after it has been ratified by success down south or overseas – and who then accuse its maker of selling out. It is there among people who don't think to support their local cinema or theatre, but rush to make negative comparisons with London's cultural offerings.

No-one would advocate the establishment of a Ministry for Truth, blaring forth unwarranted positivity about that which we who live here do and make. And, of course, I'm aware of the argument that an advocate of independence would make here: that the self-critical mindset, the chopping of poppies before they've even had a chance to grow tall, is itself the product of a colonised mindset. (Remember Trainspotting, and Renton's heartfelt "colonised by w*****s" speech.)

It is a sticky thing to talk about without sounding disloyal, defeatist, insecure – but the prospect of losing links to London and being left with a minor, apologetic sort of a culture is a sticking point for a lot of people still considering the direction of their 2014 votes. It is the ingrained fear of the old "regional variations", from back in the days when we were all beholden to actual TV schedules: and now, we say goodbye to our shiny metropolitan audience, and bring you a space-filling B-movie and some news about runaway sheep! It is the trepidation about being excluded from the audience addressed by the confident, ringing tones of the London media; the tones that say, this is the news, and that's all there is to it.

Yes campaigners are being blinkered if they don't recognise this as an issue. Part of their challenge is to assure voters that, in the event of a pro-independence result, they won't be left with an under-confident or under-nourished culture. That's true whether the concern is well-founded or a symptom of Stockholm Syndrome (which sees hostages empathising with their captors).

It shouldn't, actually, be such a difficult argument to make. There are many reasons to believe in Scotland having an arts scene that is not just capable of breathing on its own, but actually thrives on being un-yoked from London trends.

Indeed, it already does so. The Scottish dominance of the British visual arts scene since the mid-1990s has been unmissable. Fashion designers saw a similar millennial uplift in attention. Over the same period, the Scottish indie music scene has gone from producing a crop of intriguing oddballs who gained international recognition almost in spite of themselves (Belle And Sebastian, Arab Strap, Mogwai), to birthing edgy acts that still appeared purpose-built for stardom (Franz Ferdinand, Glasvegas), to fostering a seemingly fertile and supportive local scene (Withered Hand, Frightened Rabbit, Chvrches) that gets props from London and beyond without relying on those to survive. Accents even remain intact. "When I was young, all Scottish bands seemed to want to be English or American," Aidan Moffat of Arab Strap said last year. "We certainly seem more proud and comfortable with our own identity than we were in the past."

It is worth noting that the younger practitioners of these art forms don't necessarily feel conflicted or embittered about their Scottishness. Their context is different (the singer from Chvrches, for instance, was of primary school age at the time of the devolution referendum), and their sense of their culture is perhaps more developed, not less, than their predecessors'.

When old-school artist-activists like Alasdair Gray and James Kelman keep on about Scottish artists being marginalised outside Scotland, they're thinking of negative experiences they had at the hands of the Oxbridge cultural elite in the 1970s and 1980s; of Gray's contention in Lanark that Glasgow had not yet been "imagined" by artists; of the once-impenetrable dominance of BBC English on the airwaves. It is not on their agenda to notice that new cultural forms have asserted themselves; that Scotland is imagined all over the place now; that Scottish accents are far from unheard at the BBC.

And when Creative Scotland last year tried to focus its energies away from supporting small endeavours and towards funding large-scale blockbuster productions, within a sideline in "finding and cultivating celebrities who could be trained to promote Scotland", it was clear it hadn't noticed that our best and most lucrative cultural output comes from people far too cool and – yes – independent to be moulded that way.

Art forms that need bigger infrastructure – expensive technology; highly trained professionals; connections to influential tastemakers and international trade networks – do present a greater challenge to a small, independent nation than those that can be practised, at least for a while, in a garage, on a pittance, fuelled more by love than grants. Our big-name fashion designers, after all – Christopher Kane, Jonathan Saunders, Holly Fulton – don't ply much of their trade up here; and while Pixar's Brave had some nice messages about Scotland, it wasn't made here.

The Yes campaign also needs to show how it will help arts organisations to make Scotland a world player in such areas – not through sentimental talk about how great we are at stuff and how we "punch above our weight", but through practical support that might replace any severed routes to London funding. And what about collaboration – Matthew Bourne's work with Scottish Ballet, for instance, the next manifestation of which will be the very Scottish-themed Highland Fling? Is cross-pollination to be encouraged, or the sort of thing Alasdair Gray recently dubbed "cultural imperialism"? To promote what we have, locally, to foster an arts scene that stands on its own but communicates loudly enough to be heard worldwide – should we be working more with "outsiders" or less?

That might depend how much we feel we are separating from England in anger. Anger can be highly culturally productive, but it is not such a fertile basis for co-productions. Where might anger – the righteous anger of the just-freed prisoner or the new divorcee – sit in our post-independence culture? Alan Bissett, Falkirk-born novelist and vocal Yes campaigner, has a poem entitled Vote Britain in which he mockingly enumerates English crimes against Scotland – they look hard at our money, foist their royal family and Olympic Games on us, stereotype us as drunk and violent – as reasons to vote Yes. It's deliberately incendiary stuff, which he defends as a just response to "ferocious anti-Scots prejudice" in the London media. "There is a huge reservoir of resentment that Scots feel they are not allowed to express," he says, "for fear of being called negative or prejudiced."

Isn't that a reasonable fear, though? Even a good fear to have? Hearing Bissett characterise English people as Daily Mail-reading, Royal-worshipping, narrow-minded halfwits makes me cringe just as much as I did when I lived in London and had to hear everyone who learned where I came from attempt a Sir Sean accent (though Alan is wittier, I'll give him that).

One hugely off-putting element of the referendum campaigns is both sides' predisposition to snippy, nasty, personal modes of argument. This is partly down to the reliably poisonous culture of the internet, where so much political debate occurs now: see how far you can get into an exchange of views about independence online without it becoming abusive. It is probably happening under this article online right now.

Let me caution as an undecided: the name-calling, the hypersensitivity and the wild accusations are not going to create Yes or No voters, but bored abstainers. Similarly, a younger generation that has grown up with devolution and with a Scottish arts scene of pretty strong international reputation is not going to be swayed by whines about how bad things were in the past; it is going to be alienated and baffled. More interesting is talk of how a new nation might meet the modern world face-on, and use its newness to create more flexible, inclusive, agile cultural forms and means of funding them.

Complaining is a comfort zone; so is self-pity. We can all find warm places to nestle there, and doze off, secure in the certainty that people are by and large wicked and things are going to get worse. The hard thing is staying awake, staying positive, believing there's a chance to improve. I'm not necessarily making the leap-of-faith argument, although I might be getting there. I am advocating for arguments framed around what we've got rather than what we haven't, and where we might go rather than where we're unlikely to be let in. That's what I'm looking for, before I leap.

Hannah McGill is a writer, critic and a former director of the Edinburgh International Film Festival. She will be one of the panellists in our forthcoming Independence And The Arts debate (see panel).

Sunday Herald Debate: How would independence affect Scotland’s cultural life? That question will be discussed at the Sunday Herald/Aye Write debate, Independence And The Arts, to be held in the Mitchell Theatre, Glasgow on Thursday, April 18 at 7.30pm. Panellists include today’s essay author, Hannah McGill, musician and writer Pat Kane, River City actor Libby McArthur and National Library chairman James Boyle. Chaired by Sunday Herald diarist Alan Taylor, it is the latest in our series of independence debates. Tickets, priced £8, are available from www.ayewrite.com; on 0141 353 8000; and from the Mitchell Theatre, Glasgow Royal Concert Hall or City Hall.