My new novel may need justifying. Half of it is narrated by Sofia, a 17-year-old girl born in Cairo; I’m a 47-year-old man who has never lived outside the UK. More to the point, the story opens with Sofia arriving in Syria to join Islamic State – a long way from any experience of my own. Privately, I have been asked what gives me the right to tell this story. With the book newly out, I expect to have to answer this publicly. It’s a good question.

And a vexed one, debated with understandable heat over the last few years. One side sees an act of presumption or, worse, exploitation: those who are used to having an audience for their stories usurp the experience, culture and identity of those who are never heard. To object to this is right. Control the past and you control the future, as Orwell tells us; the fictional stories we tell shape us as powerfully as history does. This responsibility ought to sit with the owners of the stories – not only because it is morally right, but also because their chances of being heard diminish every time someone tells their story for them. Like a child who never gets a word in because their older siblings speak for them, they are robbed of the chance to find their own voice.

The other side responds with logic that appears irrefutable. If a writer can write only what they know, they will be confined to writing about themselves, or their experience of others. They’ll be barred from imagining what it is to be someone else. The boundaries shrink to almost nothing, and literature dies: no Anna Karenina, no Molly Bloom, no Frankenstein. Jane Austen might have shrunk from creating Darcy.

If some extension is allowed, how far can it go, and who decides? My last novel focused on a Jewish New Yorker in his late 50s, wealthy, single and living in London. I’m not Isaac Hammer any more than I am Sofia, but my life is probably a little closer to his, at least in appearance. No one ever remarked on that gap. So is that OK? Can I write a female character, provided she has a similar background to my own? A gay character? Can I move up a class, or down one? These shifting grades are so numerous that the exercise quickly becomes ludicrous.

The world has changed, old assumptions no longer hold and novelists, like everyone else, need to move with the times

But both positions are justified. Novelists must stretch their imaginations into the lives and minds of others. At the same time, this is an invasive process that does involve a degree of appropriation. The writer takes something for their use, and to any community that has suffered long misrepresentation, this will seem no different from the thousand thefts and degradations that have gone before.

Novelists are familiar with the moral shape of this relationship with the world. What we create isn’t generated from nothing; everything that comes out has at some point gone in. It follows that the richer the inputs, the better the odds that good work will result. This is why families and friends are rightly wary of us, and why Graham Greene said there was no such thing as a boring lunch, just an opportunity to gather material. If we’re doing it right, we don’t just borrow the experience of others, we absorb it and make it our own. We steal.

That novelists do not sit with the politicians and the bankers in popular esteem suggests there is a contract in place, that the world acknowledges that the benefit outweighs the intrusion. It is for good reason that most cultures prize their novelists (and that some governments fear them). But the recent debate around cultural appropriation suggests that, at its edges, the terms of the contract are no longer clear or reasonable. The world has changed, old assumptions no longer hold and novelists, like everyone else, need to move with the times. Writing fiction deserves no special dispensation.

So is there a way to navigate this difficult territory? In the words of someone who challenged me on this point, why did I think it was OK to write this book?

The first thing to say is that the decision wasn’t taken rashly. In a sense, it wasn’t really taken at all. I’d been reading about Isis for general research, and had spent days wandering through the blogs and Twitter accounts of English-speaking volunteers. The women’s stories were the most fascinating. While the men tended to be escaping something that ailed them (addiction, criminal behaviour, mental illness) on a crude promise to transform their lives (with a car, a wife, a gun), the women’s motivations were more diverse, and more complex. So many possessed a streak of striking radicalism, a reasoned disgust with the west brought to a pitch by the horror of the Syrian war and channelled into a genuine commitment to building an Islamic utopia, the caliphate. Some of the young women were especially bright, with futures full of conventional promise. As a generalisation with plenty of exceptions, the men were pursuing a fantasy, the women an ideal.

From those many voices, one began to form in my head – certain and unsure at once, zealous, as clever as it was naive. As an exercise I started to set the voice down, which would eventually become Sofia’s half of this book. Any questions around my right to write it only occurred to me once a rough draft was complete.

I knew the story and its expression were both as fully imagined, and therefore as responsible, as I could make them. The difference between a good book and a bad one so often lies in how sensitively the writer can inhabit a character. I wanted to understand Sofia, to give a true account of how she comes to see her mistakes – not to exploit her notoriety.

My intentions may not be relevant to the political question of appropriation; well-meaning theft is still theft

That’s important, but not critical. My intentions may not be relevant to the political question of appropriation; well-meaning theft is still theft. But here some special conditions applied. No one was writing Sofia’s story and, crucially, there seemed little prospect that anyone would. Dozens of non-fiction books explored the process of radicalisation, the strange hold of Isis, the reality of living in the caliphate. Excellent research has been conducted into women’s motivations for making the journey to Syria. Individual accounts of the women themselves have been confined to news reporting – and even this was patchy, because if they managed to leave Isis, they often found themselves presented with handcuffs, not publishing contracts. (And since the collapse of the territorial Islamic State, women have been tried in their hundreds by the Iraqi government and almost invariably sentenced, after perfunctory trials, to long imprisonment or death). With good reason, perhaps, the Sofias of the world would not be contributing to the narrative.

Sofia’s story, though, is worth hearing. We do need to think about it. Not because it will change our understanding of history or radicalisation, but because it might seem a little less alien once we’ve heard it, and in the process tell us something about ourselves.

The sickness she sees in the world is real, and her rejection of it is a teenage rebellion – extreme in degree, but no different in kind. At a panel discussion I attended on the phenomenon of the “jihadi brides” (a phrase no one present liked), one of the audience concluded: it’s punk. And while he wasn’t wholly right, he wasn’t exactly wrong, either. Sofia goes to Raqqa because she wants to destroy the world and rebuild it in her image. Many of us will have felt the same, if more mildly; many of us with teenage children will see them convulsed by similar energies.

When I began to write the book, Sofia presented a mystery and a danger that I was not equipped to understand. By the time I finished the final draft, I had learned that more connected us than separated us. My hope is that anyone who reads the book will take a similar series of steps.

And that’s where the justification lies, I think. Fiction remains the best means we have of finding connection where there seems to be none; and the novel, of all forms, encourages a search that’s deep and sustained. By reading (or writing) one, you’ve travelled somewhere else. You’ve moved, if only slightly, towards others. In a world that finds and increasingly exploits division and difference, this is an invaluable, precious exercise.

Writers should not abuse this weighty privilege. If they are going to start a long way from home, they need to follow some rules. Mine might be: do it with the most generous intent; try to write it well and fully; and, without good reason, don’t take stories that others are already telling.

But this privilege needs to remain possible. Restrict writers from writing certain stories and we introduce division into a process that exists to break down division – and now is not the right time.