Comment: The Saturday Essay - As self-portraits show, artists are not all that interesting

In the catalogue to the exhibition of Rembrandt self-portraits that opens next week at the National Gallery, we are reliably informed that this segment of the Dutch artist's oeuvre is "unique in art history, not only in its scale and the length of time it spans, but also in its regularity". But Rembrandt's production of self-portraits - at least 40 paintings, 31 etchings and a few drawings - is unique only if we discount the art history of the last 40 years. Nowadays, it is not unusual to find artists whose oeuvre consists of little but self-portraiture.

The photo-artists Gilbert and George and Cindy Sherman, the sculptors Antony Gormley and Marc Quinn and the painters Francesco Clemente and Jenny Saville have built their careers on examining themselves. Most performance and video art involves a relentless staging of the self: Orlan invites us to watch her increasingly drastic bouts of plastic surgery, while Mona Hatoum takes us on a magical mystery tour of her own body, courtesy of fibre optic cameras plunged into every orifice. It is surely no accident that Tracy Emin's appearance on the short list of this year's Turner prize, and her being odds-on favourite to win it, coincided with the opening of Rembrandt by Himself. For all of Emin's mixed-media installations and performances are relentlessly autobiographical - a rake's progress.

The groundwork for this self-obsession by artists was laid in the Renaissance, and it went hand in hand with a social and cultural revolution. Self-portraiture first becomes an issue in 15th-century Florence. The independent self- portrait was a useful promotional tool, as artists strove to improve their social status and be regarded as gentlemen .

There is a quantum leap in the idea of the self-portrait during the Romantic period. Many self-portraits situate the artist in his studio, surrounded by suitable props, and during the early 19th century the daily life of the artist became an integral part of artistic self-mythologising. For the first time, museums were founded that were devoted to the life and art of a single artist, many of which were set up and stage-managed by the artist himself. They represent an expanded idea of self-portraiture that features not only works of art but also personal mementoes that have the aura of religious relics. The advent of the single-artist museum also marks the birth of installation art, for artists had to start thinking in terms of orchestrating the contents and mise-en-scene of entire rooms and buildings. Nothing could be left to chance: everything - even down to the furniture and fittings - was an integral part of these one-man shows.

The first of these confections was financed and designed by the great Neo-classical sculptor Antonio Canova. It was located in Possagno, his birthplace near Venice. Canova laid the foundation stone for the Tempio that was to house his tomb on 11 July 1819, dressed in red papal uniform adorned with his numerous honorary medals. It was to be a Gesamtkunstwerk, inspired by the Pantheon and the Parthenon. Canova designed everything, and even painted some execrable altarpieces. The tomb contained his body minus the heart, which was buried in a tomb in Venice, and the right hand which was kept by the Venice Academy.

In some respects, it is surprising that the first shrine to an artist should be built by a sculptor. This is because self-portraiture was overwhelmingly associated with painting. The first major collection of artists' self- portraits, founded by the Medici in Florence in 1664 and displayed in the Uffizi, consisted entirely of painted self-portraits. The only sculptors to be included are there because they painted their own self-portraits .

It was the complex, collaborative nature of sculpture that made it hard to take seriously the idea of sculpted self-portraits. Goethe complained about the factory system that was destroying all the arts; only painting stood apart, though he thought it would not be long before the "large- scale painting factory" arrived.

So the grandiosity of Canova's gesture in building his shrine was understandable. He needed to pull out all the stops to allay the growing suspicion that art in general, and sculpture in particular, was yet another impersonal product of industrial society. It was of vital importance that the shrine was located in Canova's birthplace. Canova left Possagno at the age of five and set himself up in Rome at 22, from where he travelled all over Europe. But now, in Possagno, he had engineered a posthumous family reunion - the prodigal sculptor and his footloose sculptures had come home.

In effect, the shrine of the artist - the expanded and seemingly immovable self-portrait - bids to oppose industrialisation and the globalisation that is a natural consequence of it. But the shrines are also vehicles for ideas about roots and ethnicity. Such museums proclaim: "This is the site where my genius was born." During the 19th and 20th centuries, museums were opened in the houses of Old Masters such as Durer, Rembrandt and Michelangelo, and modern masters such as Ingres, Rodin and Monet.

The most recent manifestation of this phenomenon has just opened in Edinburgh, in a museum belonging to the National Galleries of Scotland. The veteran globe-trotting sculptor Sir Edouardo Paolozzi (born in 1924) has helped them to construct a permanent "re-creation" of his London studio. The Paolozzi gift includes some five thousand sculptures, sculptural fragments, works on paper, home-made furniture, a mattress with bedding, suitcases, tools, boxes of small plaster casts, toys, manuscripts, model aeroplanes, pieces of electronic circuitry a musical keyboard, an archive of photographs and slides, nearly 3,000 books and catalogues - some intact, some torn apart - and at least two self-portraits.

It made perfect sense for the opening of the studio complex to coincide with the opening of the Scottish parliament. Ignore the fact that Paolozzi, the son of Italian immigrants, left Scotland for ever at the age of 20. The stone of Scone left Scotland at an early age, too. Not to be outdone, the Irish are "reconstructing" Francis Bacon's slum-like London studio in Dublin - no doubt with a self-portrait in there somewhere. Bacon left Ireland for ever at the age of 16.

Our accelerating obsession with individuality and self-expression is undoubtedly the inverted mirror image of globalisation. This is a central theme of Tracy Emin's work, and the source of much of its tension. Although only in her thirties, Emin has already opened her own museum in a rundown shop-front near Waterloo Station. The Tracy Emin Museum is open to all comers, and Emin uses it both as a studio in which to sew and draw and as a gallery in which to exhibit her latest wares. You can turn up, talk to her, watch her as the works. She wears her authenticity on her home- made sleeve.

Her works detail her frantic attempts to put down roots in a rootless world. They are at once boastful and penitential. A talismanic work is an armchair that was given to her by her grandmother, and to which she has sewn texts made from coloured cloth. Emin took the chair with her to America and sat on it when she gave confessional performances. The texts range from grandmotherly homilies to sexual revelations. It won't be long before the Tate buys a roomful's worth to help to fill the cathedral- like expanses of Bankside - and celebrates the event by mounting an exhibition entitled Emin by Herself.

But, in the not too distant future, we shall surely see the cultural equivalent of the dissolution of the monasteries. There is simply too much memorabilia, by too many artists.

The relics of artistic genius will be incinerated, thrown away, demolished, sent to car-boot sales or left to moulder in dark storerooms. Conservation departments - which are expanding exponentially, at the same rate as cosmetic surgeries - will be closed down and the staff will be found new jobs as waste disposal experts.

All those brushes and chisels, items of clothing and locks of hair, sketchbooks and death masks, video diaries and bodily fluids, all lovingly assembled and labelled, will go the way of saints' fingernails and foreskins. Before long, down-and-outs may well be seen crashing out in Prince's Street on Sir Edouardo's mattress or slumped under Waterloo Bridge in Lady Emin's armchair.

Rembrandt by Himself has opened to rapturous applause. But it is a symptom of our own self-absorption, rather than of our interest in Rembrandt or his art, that we uncritically accept his self-portraits, and an exhibition devoted to them.

If the man himself had been able to see this show, he would have been appalled. For an exclusive interest in self-portraiture represents a narrowing, rather than an expansion of art. For sure, there are a handful of masterpieces, but never can nearly 100 works by Rembrandt have been gathered together to such boring effect.

The author's book, `The World as Sculpture: The Changing Status of Sculpture from the Renaissance to the Present Day', has just been published (Chatto, pounds 25)