EVERY so often, a quote pops up from a political leader that sums up so much more than the moment.

It can speak to the underlying tides, attitudes and perspectives

that define, for good or for ill, the outlook of that leader and what they stand for.

Scotland and its politics are complex, often to a byzantine degree. Many talented and capable politicians have come unstuck

in its detail.

Once on a trip north just before his election as prime minister in 1997, Tony Blair was being interviewed on a plane by The Scotsman’s excellent political editor of the time John Penman. Asked about his plans for devolution and a Scottish Parliament, the otherwise footsure Mr Blair clearly had his focus still on the electorate in England rather than the country he was travelling to: “Sovereignty rests with me as an English MP and that’s the way it will stay.”

It was a gift to his opponents on many levels but in the end, it didn’t hold him back. That said, I suspect it made him a touch leery of the country where he was born and educated.

As we look towards the election of a new Conservative leader and potential prime minister we have the intrepid and timely journalism of Paul Hutcheon of The Herald on Sunday to thank for unearthing a far more powerful quote from the front-runner Boris Johnson.

Already seemingly unloved in Scotland, and that is just his Scottish party leader I am talking about, this quote from 2012 will be very difficult to explain or indeed sustain.

“A pound spent in Croyden is far more valuable to the country, from a strict utilitarian calculus, than a pound spent in Strathclyde. Indeed, it would generate jobs and growth in Strathclyde far more effectively if you invested in Hackney, Croydon or other parts of London.”

This quote is a thing of great beauty. It is hard to know where to begin with it. But let us respect Mr Johnson’s globally renowned educational standing as a product of the finest public school in the nation and one of the finest universities in the world.

“From a strict utilitarian calculus”. Now, whatever can he be getting at? We know it is his way of showing us how well educated he is. That is different from being clever, of course, because a truly clever person speaks in simple, clear and understandable ways, and has confidence in their own clarity. Mr Johnson used this term because it says, “look here, I am well educated and therefore born to rule”.

What I think he is referring to is an algorithm formulated by the utilitarian philosopher Jeremy Bentham who died in 1832 not long after Mr Johnson’s world view was formed.

The idea of utilitarianism was to promote actions that maximise happiness and welfare for the majority of the population. Not something that Mr Johnson has thus far shown much concern for, but there we go.

Back to Bentham.

He used seven variables or circumstances to be able to calculate the impact in his “utilitarian calculus”. In short: how strong is the pleasure? How long will it last?, How certain is it? How soon will it happen? Will the pleasure have a negative reaction? Or won’t it? How many people will be affected?

You can see how Mr Johnson probably alighted upon this with his tutor many years ago as a ripping way to justify hedonism.

Not only was this Mr Johnson’s construct but he inserted the word “strict” before utilitarian, possibly to demonstrate the immense precision and discipline of his learning.

So, we are to therefore understand that the potential next prime minister’s deeply considered, indeed philosophical, belief is that spending in the UK capital city produces the greatest happiness for the greatest number of people in the country than spending anywhere else.

Now this argument may have a point if we just assumed that because the greatest majority of people live within the immediate orbit of London that it was a simple fact, so spend there and forget the rest. Something of a scorched earth approach to the rest of the UK, but he would at least have the beginnings of a case.

But no, he goes on to say that it would be better for Strathclyde than spending in Strathclyde itself.

Now leaving aside the fact that Strathclyde Region was abolished in 1996, let us examine what we think Mr Johnson is trying to get at.

I think what we have here is probably the most imaginative and optimistic case for “trickle-down economics” that I have ever heard.

This theory argues that if you reduce the tax burden on the very richest in society they will spend and invest more in a way that benefits the poorest. This was very popular in the early eighties as a justification for the political tax cuts deployed by Mrs Thatcher. The evidence for this having done anything positive for the well-being of the broader regions and nations of the UK is, to say the least, scanty.

But Boris takes this idea so much further. He refers to actual government spend. He argues that spending in Croydon of £1000 would add more than £1000 of impact to the economy of “Strathclyde”. That would really take some doing.

I suppose it is possible if it all went on the wages of, say, a Tiree-born teacher in Croydon who then saved all of it and returned home to spend it in Tiree on a summer break. But I think these are the only circumstances in which this utterly quacking canard could be true.

Meanwhile the reality of the UK is of a growing chasm and division and inequalities. As the recently launched Deaton Review noted, while real output rose twice as fast in London as in other regions over the 10 years to 2017, this was solely because the city attracted more people and jobs.

The output per worker in the capital fell during the same period, showing that it has one of the country’s biggest productivity problems.

Therefore, the hard economic facts demonstrate that in fact the opposite is true to what Mr Johnson has asserted. And you don’t need to have passed A level Latin vocab to translate that reality.

The Conservative Party lost the confidence of Scotland and all of its MPs because it became associated with exactly the position that Boris Johnson so clearly stands for. This attitude is even more politically damaging than all the character questions of honesty and dependability currently being alleged by his party colleagues and rivals. It speaks to a belief, deeply held, and by many more than Mr Johnson.

Just how you can seek to unify a divided nation by doubling down – in a nuclear-charged way – on the politics of “London First”, north-south division, and the ultimate in voodoo economics is beyond me.

Boris Johnson’s trickle-down economy will mean time-up for the failing governing system he seeks

to lead.