IT seems a while ago now. Nearly four years have elapsed since we temporarily lost leave of our senses, driven to a pitch of hysterical anxiety by the death of our Fairy Princess in a Parisian underpass. All kinds of prophets sprung up, prophesying all kinds of doom. It was suggested by some that the days of the monarchy were over, that Diana's fate reflected that of a nation in deep depression. After all, she had made a pitch to represent a constituency of the excluded; and, if the scale of collective weeping and wailing was anything to go by, there did seem to be an awful lot of them.

A few months earlier, it was this same constituency that had elected Tony Blair and his "new" Labour government. The parallel is obvious. The irrational exuberance that greeted his triumphal stroll along Downing Street in the spring of 1997 was the same as that which expressed itself in the hysterical moaning that accompanied Diana's hearse through the streets of London a few months later.

There is a very simple reason for this. We have always loved our icons; particularly those that claim to love us. We crave affection. We want our leaders, not just to govern well, but to pretend to care about us. Diana seemed to care. Many who lined the streets of London that autumn claimed that their relationship with Diana was somehow personal. And there was certainly a sense of the personal in the relationship which New Labour spin-doctors nurtured between their leader and the British public. Blair, we were endlessly told, could be trusted. The idea of trust transforms politics into something intensely personal. The electorate, they rightly surmised, did not care that much for manifesto promises, for the endless discussion about Europe or constitutional reform or even for fox hunting. They just wanted to be ruled by someone who seemed to be nice, who seemed to care, someone they could trust.

Back in the second part of the 19th Century, the great constitutionalist Walter Bagehot composed his famous treatise, The English Constitution. His central thesis was compelling; that the strength of the British constitution depends, not upon such esoteric principles as parliamentary sovereignty or the rule of law, but upon its ability to delude. There were, Bagehot suggested, two parts to our constitution; the "efficient", which actually made things work, and the "dignified", which kept us entertained, and thus more or less happy.

Certainly, the constitution should be reasonably efficient. The various institutions of government should get the job done. But what really matters is the "dignified" bits, the ritual, the monarchy, all the icons. It is this that continues to entrance us. It is for this reason that Diana's love life fascinated us far more than issues such as reform of the House of Lords or regional devolution. In the early 17th Century, the courtier Sir James Harrington looked back on the reign of an earlier Fairy Princess, Elizabeth I, and confessed himself baffled as to why he and his compatriots could be so easily deluded. Why was it, he mused, that we insist on regarding our constitution and our politics as a "kind of Romanze"? The question is just as valid today as it was four hundred years ago.

* Harry Mead is on holiday