If Gordon Brown seeks a symbol of Britishness today, how about the divorcing McCartneys? In her 11-minute rant to the media on Monday Heather Mills, the former Lady McCartney, gave a towering exhibition of our new national characteristic of emotional incontinence.

Meanwhile, Sir Paul's statement was a quiet cri de coeur for our tell-all society: “All will be revealed.” Indeed it will, even if all must be reviled as a result.

I am all for televising criminal trials, if only to keep the cameras away from the celebrity divorce courts. Hard as it may be for this charming couple to accept, some of us take no interest or side in their affairs, although I did sympathise briefly with Ms Mills when she expressed the sincere hope that the news might now cover “important issues instead of our boring divorce”.

But whether we like it or not, this circus has important implications. As celebrity culture fills the empty space where politics and public life ought to be, it becomes an arena where bigger issues are shaped. The £24 million McCartney divorce saga leaves poorer all who value the separation of the public and the private. First our sensitive stars jointly blamed media “intrusion into our private lives” for the separation. Then, in you-couldn't-Macca-it-up style, each side tried to use the media to turn their private dispute into a public relations war, where “privacy” means having control of your own PR.

In the unhappy marriage of the public and private sides of life, both spheres are losers. The loss of a sense that some things are private means the end of any real self-awareness or space for considered reflection. Instead we are left to enjoy the reflex outpourings of the self-obsessed. This trend is not confined to media celebrities - it can be tricky to use a train or bus today without sharing the details of somebody's sex life via a “private” call on their mobile.

As for the public sphere, it is now filled with so much personalised guff and gossip that Ms Mills can almost seem like the reasonable voice of an unhinged culture. When she demanded to do her famous impression of a delusional paranoiac live on GMTV last year, they let her bang on for 20 minutes on the ground that “it's a news programme”. Then the broadcast media spent the entire day debating her demand that Europe change “the law” to protect her from media intrusion. She even told ITV: “I spoke to Gordon Brown this morning and he thinks it's a great idea.” That would be the same Mr Brown who says we have moved on from the Blairite celebrity obsession to a “new seriousness” in politics.

“I'm just so glad it's over,” said Ms Mills on Monday. If only. If this is reality, I want a divorce.

Times Recommends

• Navigating the new global archipelago
• Comment: McCain isn't Bush and voters know it
• Religion's history of self-inflicted pain