People who want the UK to stay in the EU usually belong to one of two camps. The pragmatists argue that, for most of the British public, Europe remains little more than a common market and a major source of trade and jobs. The believers, on the other hand, plead that much more is at stake: it’s about our identity and the sort of country we want to be. The former see the referendum as a war of facts and figures, the latter as a battle for hearts and minds. Both want to win but disagree on how to get there. Both might be wrong if the old adage holds true that referendums are never about the question on the ballot paper.

Janan Ganesh has made the case for pragmatism more forcefully than most: “Economic logic made us join and it will decide whether we stay. To try and lift the referendum debate beyond cost-benefit analysis to matters of principle is to treat Britons as if they were Germans, with the same traumas.” Ganesh concludes that only a hard-nosed campaign which alludes to the myriad uncertainties of divorce will win the day: “This kind of campaign is dry, cynical and boring. It will be monstered by critics, until it wins.”

Pragmatism has prevailed so far. Business remains the chief spokesman, regularly citing the volumes of trade, investment and jobs that rely on EU membership. No one would claim these are trivial matters when they affect the lives of millions of people across the country. The same goes for the familiar argument about ‘clout’ which says the UK exerts more influence as part of a 28-member club than it does alone. Britain’s cousins on the other side of the Atlantic are quick to repeat this mantra.

But can we be certain that cold reason will prevail in Britain’s febrile politics and media? Will hard economic data generate sufficient doubt about the fall-out of exit? The pragmatists believe their strategy proved its worth in the Scottish referendum. But was it really the pound wot won it?

Time for a little psychology. Thanks to the likes of Daniel Kahneman and Jonathan Haidt, who have brought neuroscience and evolutionary psychology to the masses, we are beginning to understand a little better how humans acquire their moral convictions and take decisions. It seems that our attitudes, opinions and decision-making are at once more hardwired into our core being and more resistant to factual argument than we might have imagined. We often decide from instinct and only then construct the argument to justify our action. In short, we are often less rational – and less in control of our decisions – than we think.

What might this tell us about the debate on Britain’s place in Europe? Aside from the notion that facts, figures and rational argument can never truly ‘win’ a debate, the larger risk for any campaign that confines itself to cost-benefit analysis is that it leads to defeatism – “better the devil you know” – and suggests that European Union membership is, at best, something to be endured. When those arguing for exit are reaching for heavier guns – they invoke a threat to freedom and democracy – the rational arguments can start to look soft-willed rather than hard-nosed. While Ganesh may be right that the British never fell in love with Europe and never will, the believers may be right to question cold economic logic: will it be enough to do the job?

The refugee crisis arrives at a critical moment. It may yet change the terms of the debate and in a way that strengthens the case for membership. Bear with me. The crisis has reminded us of three basic truths. First, neighbours matter. The world can digitise and globalise all it wants but what doesn’t change is our neighbours: they remain close to us whether we like it or not, and their actions affect us directly. Second, today’s messy world is full of difficult problems that no one can solve alone; close cooperation and strength in numbers are more necessary than ever before. Third, no country can escape its history. This summer reminded us that the story of human migration is the story of Europe, and the story of modern Britain is entwined with that of our neighbours. That great conciliator of reason and faith, Simon Schama, has no doubts about what the refugee crisis means: “It is this issue, not the question of sovereign debt, that will decide whether Europe lives or dies as something other than a fine tuner of the business cycle…Pray that it might be the moment when Europe – including Britain – finally discovers that long-lost item of its political anatomy: moral backbone.”