THIS IS WHAT happened when John Lennon first met Yoko Ono. It was at an avant garde art exhibition at the fashionable Indica Gallery in London. In the middle of the room, Yoko had placed a ladder, on the top of which lay a magnifying glass. This could be used to read some tiny letters written on the ceiling. So the Beatle duly ascended, picked up the magnifying glass and read the scribbled word. And all it said was this — “yes”.

It was that word that made Lennon stay. As he told countless interviewers in the coming years, if the scribbled word had said “no”, he wouldn’t have hung around.

Now, as a Beatles devotee, I’m perfectly well aware that in addition to being a genius, John Lennon was an idiot. And anything to do with the absurd Yoko Ono has me on my guard. Yet I watched a TV programme last week that made me wonder if Lennon wasn’t on to something after all.

David Davis and David Cameron were on Sky News, taking part in another debate (surely it must be over soon, somebody, please, please, do something) when an argument began over the new licensing legislation. This does not sound very promising, I agree, but, as it happens, the exchange turned out to be one of the most significant of the entire leadership election.

“We have a situation where the centre of many cities and towns in this country are no-go areas for decent people,” said Mr Davis, giving 8 o’clock as the curfew for decent people and arguing that the Government was making things worse. I have listened to Conservatives making Mr Davis’s point in roughly similar language countless times and thought nothing of it, so David Cameron’s reply took me by surprise. “We must not make everyone who wants to go out and have a drink on a Friday and Saturday night sound like a criminal,” he said.

The moment I heard this I recognised the debate the two were having. An unresolved, half-buried Tory argument was rising to the surface. Should the Conservative Party paint the skies blue or should they paint them black?

Ponder for a moment which of the contenders was correct and it is obvious that they both are. Eight o’clock may be on the early side, but Mr Davis is right that many people avoid town centres at night because of the drunken, rowdy behaviour of others. And Mr Cameron is right that it is madness for the Conservative Party to regard every young person in town in the evening as indecent. Lots of people are just out to have a good time, and there’s nothing wrong with that.

It is precisely because both men are right that the strategic choice they each made is so fascinating. The same set of political facts can be expressed in two entirely different ways with a completely different emphasis.

In the very early days of opposition, after the devastating result of 1997, the Conservatives debated these alternatives openly, even giving the different options labels as a shorthand. The party could be pessimistic about all the great threats overhead (painting the sky black) or it could be optimistic about the possibilities for Britain (painting the sky blue).

But the debate never came to a conclusion. The “realities” of opposition kicked in, taking over from the academic discussions. Without fully realising the choice it was making, the Tory party began to paint the skies black, became the pessimistic party. This country is being strangled by regulation and taxation, criminals are taking over our streets, family life is collapsing, immigration control is a joke, alcoholism and drug abuse is rife, the constitution is crumbling and we are being subsumed in a European super-state. Oh yes, and no one decent can go out after 8 o’clock.

Eight years later it seems clear that this choice was the wrong one. And Mr Cameron’s intervention in the Sky debate suggests that he realises it too.

A Blue Skies party might say this — that this country is already prosperous but untold opportunities lie ahead for all if we build a flexible low-tax economy; that one of the greatest advances in social policy of the last 30 years is that we now know that crime can be beaten with the right policies and that in other countries this is happening; that immigration can be an immensely positive thing and that assimilated communities have been enormously successful and will continue to be so provided we get the system under control; that many cities outside London are booming and that there is now so much to do after 8 o’clock. I could go on, but you get the idea.

In the mid-1990s President Clinton’s chief strategist Dick Morris came to a similar conclusion. The Democrats, he said, reminded him of a group of tenants who would greet the collapse of their roof with chuckles because it meant trouble for the landlord. Changing that attitude, which he found very difficult, was one of the keys to Bill Clinton’s extraordinary political recovery from a landslide mid-term defeat in 1994 to re-election in 1996.

The reason that optimism is a superior political position to pessimism is really quite simple — association. Why do you think car companies advertise their products with attractive women? It makes their cars seem sexy. Why do fundraisers serve you a meal before they pitch to you? It makes them seem warm and generous. Why did the Persians slay the messenger who brought news of defeat? It’s all because of association, the linking of message, messenger and environment. John Lennon is not alone in wanting to see the word “yes” at the top of the ladder.

A Black Skies party is itself viewed as dark, threatening, likely to bring about precisely the problems it warns against. The public slays the messenger that brings it bad tidings.

It doesn’t have to be like this. My mother likes to describe pessimists as those who can only see the holes in the Emmenthal. It’s time for the Tory party to wake up and see the cheese.

daniel.finkelstein@thetimes.co.uk

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