As the Founding Fathers might have said: we hold this truth to be self-evident. Politics is increasingly bound up with the preoccupations of the Westminster bubble, increasingly cut off from the lives of real people. Who could disagree with that statement of the obvious? Answer: a lot of serious people – the survivors – who are still in the Labour party profoundly wish that they had done so at the time. But they acquiesced in the bursting of the bubble.

In consequence, any hairy trot prepared to forgo a pint of beer in the local Poly bar could use the three quid to take over the Labour party. So they have, and there is no dislodging them. For the price of a pint the party was lost.

It is a sign of the moral, intellectual, political – and psychological – collapse of moderate Labour that the best challenge on offer to Jeremy Corbyn is Owen Smith. He would have been a worthy member of the local band at LLanabba Castle in Decline and Fall, the second greatest attempt to sociologise the Welsh. Neil Kinnock ought to be grateful. He is no longer the most prominent Welsh windbag in modern British politics. When the now Lord Kinnock was Leader, it was pointed out that shortly after he was born, he had been immortalised, by Dylan Thomas in Under Milk Wood (the greatest attempt), as the character of No-Good Boyo. Well, Owen Smith has now taken over. He makes Neil Kinnock sound like Lloyd George.

But the risks of group-think are apparent in a context more important than Labour. Fresh air, exercise, cutting down on carbon emissions, helping the environment: surely everyone ought to be in favour of cycling? Perhaps, but not in London. In this enormous city, it will always be a case of four wheels good, two wheels dangerous and eccentric. Unfortunately, Mayor Boris saw nothing wrong with either danger or eccentricity. Frustrated in his desire to spend £50 billion and climbing on an airport that could never have worked, he made do with low single billions on bicycle lanes.

Although there would never have been a good moment for such an absurdity, Brexit is seriously unpropitious. In Frankfurt, Paris and Dublin they would like to eat the City of London’s lunch. Our transport problems can only assist their enticements. The business man who has just spent an hour and a half getting from the Connaught hotel to Canary Wharf, while being driven past miles of empty cycle lanes, will not automatically conclude that London is the easiest place to work in. It may be only a marginal factor. But in difficult times, margins matter. Boris bikes are cutting economic growth.

When Norman Tebbit was in Margaret Thatcher’s Cabinet, he was a well-known antidote to group-think. An idea would be full sail towards consensus. Then Norman would stroke his chin and say: ‘Now, if I were the opposition front-bench spokesman, what would I make of that…’ A shredding process would follow. Three minutes later, there would be general agreement on the need for further consideration.

Any wise organisation, whatever its purpose, should always ensure that there is a curmudgeon in the boardroom, who will invariably subject group-think and fashion to intense scrutiny.