MAY Day. The coming of spring isn't what it used to be. Last Monday in London two distinct significances the term May Day has acquired in contemporary usage unfortunately collided: a celebration of people power and a distress signal. It is perhaps an indication of how fragmented our society has become that it wasn't easy to identify who the people were or to decipher the confused nature of the distress.

Instead of the traditional columns of orderly workers marching in solidarity, there were amorphous crowds of people who often didn't seem to agree with one another, never mind the capitalist system. The old banners that used to be carried on these occasions usually declared an affiliation to a place and to a union, implied coherence in diversity. They were a mobile map of the socialist movement. On Monday the weird and wilful banners suggested a gathering of people many of whom had no more in common than the fact that they had come to the same place.

It could be argued, of course, that the continuing connection between the old May Day and the new is a shared opposition to the injustices of capitalism. I have no objection to that. Capitalism seems to me a form of one-way democracy. It promotes the democratic right of each to live in an undemocratic relationship with others, the democratic right of each to try to acquire a position of financial oppression over others. The comparative success of some within capitalism is dependent on the comparative failure of others. If you doubt that, try to imagine a society in which everyone is a millionaire. If you succeed in doing so, get treatment.

But any belief last Monday's protesters had that they were engaged in a meaningful attack on capitalism was discredited by the silliness of their antics. This was protest as vaudeville. If the clown wants to play Hamlet, he must first give up his full-time job as a clown.

It's true there's nothing that says demonstrations can't have some fun and last Monday had its moments. I thought the strip of turf placed on the head of Winston Churchill's statue, giving him a green Mohican, made a neat point. It left us with a memorable image of the distance our culture has travelled from social sanctimony to personal irreverence. It reminded me of the man hanging from a lamppost at the beginning of the film I'm All Right Jack, who is returning Churchill's victory sign when he suddenly turns his fingers round to make the gesture mean something altogether less comfortable, subverting the new peace into a different kind of war. Also, that turf could be easily removed to restore Winston to his former dignity. It was a joke which knew it was only a thing of the moment and didn't get above itself the way graffiti can, with pretensions to longevity.

Unfortunately, the forms of protest never rose above the level of such gestures to aspire to anything approaching meaningful political purpose. Some of the less reactionary commentators on the event have reminded us of the rights of the young to be subversive, as if outrage could never be more than a side-effect of hardening of the arteries. But there is a question of how immature protesters can be allowed to be and still claim to be expressing more than their own petulance. Monday's caperings carried as much threat to the bastions of capitalism as a kindergarten sit-in. If you don't pay attention to us, we'll break our toys.

They planted hemp and created little ponds in Parliament Square, which must have caused consternation in the multinational boardrooms. They scrawled graffiti on the Cenotaph, which was a bit like urinating on the graves of the generations who had helped to preserve their right to protest in the first place. Then, for a grand finale, some of them heroically sacked a McDonald's. The first of these was just silly. The second was offensively silly. The third was criminally stupid. Anyone who thinks that wrecking a McDonald's is a significant attack on capitalism would have believed that a good way to destabilise Imperial China was to murder a border guard and run away.

Far from being an expression of youthful idealism, this was radicalism with Alzheimer's. It didn't know from one minute to the next what it was going to do. Not only did it not know where it was going, it had no idea where it was coming from.

John Vidal of the Guardian witnessed a moment which seems to me to lie at the core of these pathetic charades. He watched a man from Peckham called Bill make a heap of all the socialist and Marxist literature he could find and start a small bonfire with it, to the cheers of those around him. "It's just boring politics," Bill said sagely. "I'm just into thinking for myself."

Let's hope Bill keeps on thinking for himself, preferably in a padded cell. That way he might not pollute the mental climate of the rest of us. The offence doesn't lie in the rejection of Marxism, which many of us have rejected or, as in my own case, never subscribed to at all. The offence is in the cavalier and total rejection of one of the most fiercely creative intelligences in history. You don't have to agree with Marx to learn from the intensity of his thinking. Bill and some of his co-protesters as radicals? They would have had a good night at the burning of the books in Nazi Germany. They might as well be the descendants of Pol Pot in their eagerness to establish a kind of intellectual Year Zero. The offence is in a philistine obliteration of the richness of the past.

If times like Monday are any sort of compass, that would seem to be where we're headed - into a perpetual and vacuous present. Never mind the boring speeches they used to have on these occasions. Let's just do our own thing. Never mind that the point of protest and demonstration is to mobilise the majority, not alienate them. Let's do whatever occurs to us and not care who is offended. Never mind that political power is process, not event, and that it is a power which can only be effectively influenced by being understood and infiltrated. Never mind that public protest can help in this, but only if it stays coherent within itself and finds a specific context which will achieve maximum impact. Let's thumb our individual noses at the worldwide power of capitalism. That ought to do the trick.

No wonder the chaos of Monday evoked a confusion of distress. Reclaim The Streets was distressed by the violence of the anarchists. The anarchists were distressed by the passivity of Reclaim The Streets. The right-wing papers were distressed by everybody who wasn't a statue. Tony Blair was distressed that Britannia had lost her cool.

But for me there was a distress that swallowed up all of these. It was the distress of having to watch political radicalism drowning in a social philosophy as shallow as those puddles in Parliament Square.