“Dentist?!” she exclaimed. “You can’t be serious. What happens when they cure all teeth problems? Where will dentists be then? No, Bobby, people will always need entertainment. I’m looking out for your future. You’re going into show business.”

McKee took his mother’s injunction more seriously than even she might have intended. For in addition to his career as a screenwriter, Robert McKee has become the leading expert on the importance and construction of stories. And if there is one thing that exceeds mankind’s need for entertainment, it is his need for stories.

McKee thinks that without a strong, carefully built story, a film is bound to fail. Characters, dialogue, cinematography, arthouse sensibility — nothing can save a movie from a bad plot. He’s right, but I’d go further. It’s not just films that live and die by the quality of their stories, it is humanity.

To explain what I mean, let’s turn to the political events of the last week. The extraordinary behaviour of Gordon Brown and Labour MPs has attracted a number of descriptions with a common theme. They’ve gone mad, he’s bonkers, what a bunch of nutters, they are having a nervous breakdown, the whole lot of them have lost the plot.

It is easy to see these remarks simply as cheap insults. (Though well deserved. A vicious plot by a group of people labelling themselves Amicus? And Mr Brown pretending that he was joking about nannies when sitting in that car. Doesn’t he know that nannies are never a laughing matter?) But I think the Labour Party, and particularly Mr Brown, would be better off if they didn’t regard all this as an attack. Instead they should embrace the apparent insults, treating them as acute political analysis, laden with helpful pointers for the future.

For if Gordon Brown understood that “nervous breakdown” and “lost the plot” are good, accurate descriptions of his party’s condition, he would be able to sweep off the table a large number of duff pieces of advice that are being offered to him.

Here’s a list of this duff advice — Project Gordon with new ties and false bonhomie; the Milburn-Byers call for a debate; the need to make constant speeches asking for unity; the adoption of the policy agenda of the younger Cabinet members; the suggestion that he announces an immediate withdrawal from Iraq and change tack on the Middle East. Unfortunately for Mr Brown, this list of advice is almost exhaustive. There isn’t much else knocking around. Nevertheless, if he sees his own and Labour’s problems clearly he will see that, whatever the policy merits of these ideas, not one of them offers him and his party political salvation.

In his moving book The Scent of Dried Roses, Tim Lott tries to explain his own breakdown and the decision of his mother to take her own life. If depression is a purely physical thing why do people attempt suicide at certain moments in their lives and not at others? And why do some people attempt suicide, while others would never dream of it?

Lott’s conclusion is that we all tell stories to ourselves and others about who we are. They are carefully constructed and essential to our identity. When those stories are no longer possible to square with the world as it truly is, it can produce, in those who are susceptible, a nervous breakdown, even suicidal feelings.

I believe that the Conservative Party suffered just such a nervous breakdown in the early 1990s. Its self-image as economically competent, politically unified and electorally supreme became impossible to square with what was really happening. Suicidal behaviour soon became apparent.

And I believe that the Labour Party is having a nervous breakdown now. The new Labour story was of a small band of brothers changing their party beyond recognition, creating an irresistible force that crushed the awful Tories, and while remaining unbelievably disciplined, dominated the political landscape and connected with Middle England.

Much of this narrative has simply run its course (getting rid of the awful Tories, say, is no longer a public preoccupation) or is no longer possible to square with reality (the idea of being a band of brothers and being very disciplined has gone for a burton). And suicidal behaviour has duly followed.

Advising Mr Brown to solve this problem by changing his image will not work. You can only save a movie with a good plot. Policy ideas won’t work either. Such ideas are like inserting an extra special effect into a boring, messily complicated film. What Mr Brown needs is a narrative.

As Robert McKee argues in his book Story, a classic narrative is a tale of personal struggle against adversity producing change in yourself and your environment. Mr Brown must tell us the forces against which he is struggling, the objectives he hopes to achieve, the challenges he will meet along the way and the journey he has had to travel before he has even begun.

The current Gordon Brown story won’t do. The current story is of a gloomy, if competent, obsessive determined to overcome Tony Blair in order to complete his journey to No 10. How sympathetic does he expect voters to be to the man starring in this film? And when he has made it to Downing Street, what then? Lots of people have said that Gordon Brown needs a new speechwriter. Maybe so. But before then, he needs a new screenwriter.

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