My second favourite religious joke is an old Jewish joke (which I read in the Harvard Review, so I assume it has passed the political correctness test).

Two Jews pass a church displaying a sign promising $1,000 to all new converts. After much debate, one of the men decides to take up the offer and enters the church. An hour passes, then another as the friend waits outside. Finally he comes out of the church and his friend eagerly asks, ‘So, did you get the money?’ The first man glares back and says, ‘Is that all you people think about?’

You could transfer this punchline to the Scottish independence debate.

Imagine you proposed divorcing your husband, and he responded by compiling a spreadsheet listing the additional costs of maintaining two households and implored you to stick together to save on the household bills. The thought is hideous. Any appeal to equate loyalty with economic self-interest is instinctively repellent to normal people. The argument that two countries should stay together solely for financial reasons may be economically sound but it is psychologically tone deaf.

Allowing money to affect your allegiance never goes down well with the punters, as Judas and Ephialtes both discovered. The ‘no’ campaign should have spotted this. Most Eurosceptics find it distasteful when the case for remaining in the EU is framed in purely economic terms. In any case, economic arguments will inevitably favour greater centralisation, since the cult of economics is obsessed with the theory of ‘economies of scale’ (a doctrine which has been used to justify many corporate mergers, even though all evidence suggests these mostly fail).

The late Elinor Ostrom showed that the human reality is more complex than this. Human organisation is naturally polycentric — think of ancient universities, which are divided into both faculties and colleges, or the way the military is structured. Some things are better centralised; other things aren’t. In city police departments, it makes sense to centralise specialisms such as forensics, but for all the supposed economies of scale, things get worse if you combine separate police precincts into larger, anonymous units, where group cohesion breaks down. In part, unity within a group is driven by rivalry with nearby groups. This can be found in nation states.

When you do need to create unity in larger groups, you need more than narrow appeals to self-interest: you need emotional appeal too. Writing about the ‘cognitive revolution’ which transformed Homo sapiens into a uniquely social species, Yuval Noah Harari suggests ‘the truly unique feature of our language is not its ability to transmit information about lions or about men. Rather, it’s the ability to transmit information about things that don’t exist at all… Many animals and many human species could previously also have said something like careful, there is a lion. But, thanks to the cognitive revolution, Homo sapiens acquired the ability to say [….] there is a lion-man spirit which is guarding our tribe.’

The simple problem is that the ‘yes’ campaign can invoke the lion-man as much as they like but the ‘no’ campaign can’t. ‘Nationalism’ is somehow OK when prefixed by the word ‘Scottish’ but not by the word ‘British’. No one on the right can praise British culture, because it makes you sound like a skinhead, and nobody on the left can do so because you have to maintain the pretence that all cultures are equally admirable except for those practised by white people you don’t like. So they talk about money instead.