I've never been - I start feeling strange at design expos. I'm the same flicking through a design magazine, or browsing the shelves of a designer shop. The closest I came to a nervous breakdown was in the cutlery department of a Conran Shop seeing my face multiplied and distorted on the back of spoons. These nodes of highly concentrated design radiate something odd. Quite frankly, it's unnatural to be completely surrounded by things that are more confident of their place in the world than you.

I do wonder why people go to Milan. What are they really going to see?

Unlike art, music or poetry, Design does not claim to illuminate the human condition. Its excuse is that it does something useful: providing something to sit on, something to sleep in, something to eat off. Designers will often quote 19th century Chicago architect HH Richardson: 'Form follows function'. They use this phrase to justify the shape they give things. It's a way the designer can abdicate responsibility, suggesting, somewhat fatalistically, that the product is an inevitable consequence of the brief - and certainly not a personal and subjective choice made by the designer.

But the odd thing is that design isn't really about function either. If it was, we wouldn't need any new designs for chairs - its not as if all those millions of existing chair designs have suddenly become redundant.

There was a time when design believed it could change the world: emancipate the working class; bring hygiene and democracy to the dirty and oppressed. Design had a morality and a higher purpose. Modernist design: white villas in Parisian suburbs, Helvetica, Square, chromed teapots, had a faith not just their own modest function, but in the grand purpose of design: to make the world a better place.

But figuring out what design believes in now is tricky.

If you really want to know about design, you should turn to Brett Easton Ellis and Douglas Coupland. Between them, they have a lucid understanding of the world of objects that surround us.

That these North American novelists might have such a keen eye design could be explained by the last great design critic, Reyner Banham. He argued the Wild West was won by industrial designers:

'The quintessential gadgetry of the pioneering frontiersman had to be carried across trackless country, set down in a wild place, and left to transform that hostile environment without skilled attention. Its function was to bring instant order or human comfort into a situation which had previously been an undifferentiated mess, and for this reason it is so deeply involved with the American mythology of wilderness'

Fast forward 120 years to the frontiersmen great great grandsons, and eavesdrop dialogue from American Psycho where Manhattan yuppies are comparing business cards:

''Cool colouring' Van Patten says, studying the card closely.
'That's bone' I point out 'And the lettering is something called Silian Rail'

The absolute importance of these useless design decisions is played out through one-upmanship. First 'Eggshell with Roamilan type'. Then 'Raised lettering, pale nimbus white'.

Banham was writing about simple products that forged nations. He understood design as tool and machines, which extended the reach, and strength of the human being. A kind of Futurist Modernism.

Couplands novels contain strangely magical descriptions of blank and provisional IKEA furnished landscapes - altogether less heroic, but certainly more modern. Coupland and Ellis are exploring the uselessness of design in its wonderful and horrific redundancy. They are Pop Art soliliquies, which recognise the gloriously schizophrenic nature of contemporary design.

Looking back, there is a particular moment that defined the cultural shift in the purpose of design. Design changed one day in 1990 with the production of Philippe Starks 'Juicy Salif' - that ribbed, chrome teardrop on spidery legs. It was striking, beautiful : it looked like different to all that other prosaic kitchen stuff. It looked more like sculpture than sculptures. Its been called 'the most controversial citrus fruit squeezer of the 20th century' - an American Psycho-ism if ever there was one.

It was the culmination of the previous decades idea of design. In the 80s, product design was what you said about yourself to other people. It was an era which re-made the whole of the history of objects. Lucky Strike cigarettes, Rietvelts Red and Blue Chair, Levis Red Tab 501s, Mackintosh's Glasgow School of Art. Objects were plucked out of historical context `and canonised in the pages of style magazines. It created a different story about design: depoliticising Modernism, cutting loose from all that tedious 1930s rhetoric. It fetishised certain utilitarian products, turning them into sought after commodities. Lifestyle replaced ideology as the driving force of design.

The Juicy Salif was as much a part of the 1980s as Robert Palmers 'Addicted to Love' Video. Both were super slick, sexy and useless at squeezing lemons. Stark astutely recognised that usefulness wasn't the same as function.

The 1990s saw design culture turn on itself. It started to think all kinds of quirky, dark thoughts. Design had become so slick, perfect and commodified it suddenly felt wrong. Designers wanted to be real; they wanted to make real things again. They craved the kind of authenticity that had been erased by the 1980s.

The high watermark of this kind of anti-design was Do Create. A project produced by design company Droog, advertising agency KesselsKramer and a whole host of designers. Asking the user to smash, dent, stick and prop its furniture up showed that it wasn't about what it looked like, but about how you used it. This kind of wonky, vaguely serious, slightly ironic, partially political, quasi-fine art approach has seen design explore strange and perverse routes.

Design delights in its perversity. It blew up the traditional idea of function and messed with materials. Though it is often charming, I think it secretly wants you to be horrified at you relationship with the world.

Which might explain why furniture designers are blowtorching Pianos on the front cover of design magazines and selling the charred carcass to an 'influential trend-forecaster'. It's design as a quirky morality play.

Anti-design is the designers revenge for what Conran, Alessi and all those other 80s design characters did to design. Its revenge for making design separate from the real world.

Design has evolved from use to uselessness - but in a good way. Perhaps it should become even more useless - evolving into lumps of sensation - dense clumps of feeling. Flat packed feelings to distribute around our homes. A Tom Dixon lump, a Marcel Wanders pile, a Ron Arad slump. Design is still restrained by these old fashioned Modernist morality of function. Design is a bubble that preserves a sensation - a fleeting feeling made solid.

Think of Jonathan Ive, Apple computers product designer, somewhere in a studio on Infinite Loop, Cupertino immersed in a Californian zen-ness. His design for the iPod isn't the hardware - the internal electronics - it's the sensation. It's the feeling
of chilled smoothness. It makes the product feel like it isn't there. Touching it feels as though your hand is coated in something cold and wet. It's a feeling frozen into a plastic case.

Perhaps design is the physical manifestation of invisible stuff. A bit like the opposite of Marxs' description of effect of capital in the Communist Manifesto: 'all that is solid melts into air'. Product design does the opposite. It makes solid-ness out of the fleeting imaginary world of ghosts and shadows and dreams.

Design is culture batch produced in three dimensions. It casts us in the role of theoretical archaeologists, picking over examples of our own culture. The new products being launched in Milan will, for a while, make the familiar world slightly strange. This mild alienation affords a different view of our own world.

Design is perverse, riddled with contradictions. It's both inane and intensely serious. It's as much about idea as it is about a thing. Above all, design is usually a glorious failure - either to fulfil its ambition, to perform as intended, to look quite as good as it should or to sell as well as anyone wanted.

Perhaps because of the battle design has between reality and utopia, I've adopted a new favourite designer, 'Magic' Alex Mardas. He was a Greek TV repairman who, for some reason was hired by The Beatles to run Apple Corps electronics arm. He promised to build an artificial sun, a telephone you told who to call, wallpaper loudspeakers, a house which hovered supported by an invisible beam, a flying saucer, a solar powered electric guitar. They asked him to install their recording studio in Savile Row. Mardas promised miracles: EMI (Abbey Road) had only just expanded to eight-track recording, Apple would have 72- track. And there would be no need to use those awkward studio "baffles" around Ringo to prevent leakage of his drum sound into the other microphones. Magic Alex would install an invisible sonic force-field which would do the work unobtrusively.

He got as far as wandering around in a white coat, with a clipboard, muttering and trying to place box-loads of tiny loudspeakers around the studio, one for each track, and a mixing console cobbled from bits of wood and an old oscilloscope.

His grand ambition, utopian visions allied to their totally inadequate and pathetic manifestation is a kind of exaggeration of the feeling every designer has when the thing that has occupied their thoughts finally produced as a real thing. The gap between the idea of something and its production could be named the 'Mardas Gap'.