Arts: Try this for sheer size: You need six months and a pair of roller-skates to do justice to the new Louvre in Paris. Andrew Graham-Dixon flat-foots it in a day . . .

The Louvre, it was announced at the opening of the museum's new wing, the Aile Richelieu, is no longer to be known as the Louvre. Its new name is 'Le Grand Louvre', the big Louvre, although whether this will catch on remains to be seen. Francois Mitterrand (Mitterramses I as he is now known in Paris) is not the type to pass up the chance to blow his own trumpet, and since the new and vastly expanded Louvre, complete with glass pyramid, was largely his idea, it may be assumed that he was largely responsible for rechristening it. Doubtless he could have done better, but there is, none the less, something apposite about 'Le Grand Louvre'. The Louvre always was pretty big. Now it is very, very big indeed. Much bigger than anyone else's museum, anywhere else in the world. Francois and the rest of les Francais presumably just want to be sure no one misses the point.

As new wings go, the Aile Richelieu is fairly impressive although also, to the unsuspecting tourist or first-time visitor, likely to prove somewhat daunting. The statistics begin to give you an inkling of its sheer size - some 12,000 works of art distributed among 22,000 square metres of exhibition space - but statistics are, always and inevitably, somewhat abstract. Imagine the British Museum, the Victoria and Albert Museum and the National Gallery combined, multiply by two, and you will have some idea of the scale of the Aile Richelieu and the tremendous heterogeneity of its contents (and remember that this is just the new addition to the museum).

It would have been exhausting but just about possible to pay a fleeting visit to all the galleries in 'Le Grand Louvre' in a day if the authorities had not banned the use of roller-skates inside the museum. As it is, forget it. The place is full of tourists with glazed eyes, reeling picture-drunk and sculpture-glutted from one gallery to another, putting off the moment when they have to admit that they have been defeated by the sheer scale of it. There is always another purring escalator, it seems, inviting you to ascend or descend to another grand circuit of marble halls and some entire new section of the museum of which you were previously unaware.

Periodically, in those parts of the museum where it is possible to sit down, you come across groups of people in shell- suits, their headsets buzzing unattended around their necks. Slumped and exhausted, they sit there: entire coach parties bearing mute testimony to the fallacy of a notion of cultural tourism according to which a great museum can be 'done' in a day. The gigantism of 'Le Grand Louvre' is intimidating but it may also prove to be salutary. Perhaps a museum this enormous may force people to modify their ideas about how best to experience works of art. The days of the march past, in Paris at least, may be numbered.

All of which gives the reviewer something of a problem. When it would take (and this is an entirely realistic estimate) something like six months to view the works contained in the Aile Richelieu with anything like a reasonable degree of concentration - and considerably longer to begin to assess the ways in which those works have been installed - how on earth do you go about the job of reviewing it? Attempting to do so - given that the Aile Richelieu contains, among other things, the French national collections of Mesopotamian, Iranian, Egyptian and Moghul Indian art and artefacts; of French sculpture from the ninth to the mid-19th centuries; of European decorative arts from the Middle Ages to the 19th century; as well as one of the world's greatest collections of French and Northern European paintings from the 14th century to the end of the 18th - would seem a touch hubristic. It would be like attempting to make a snap judgement on human civilisation during the last millennium or so. Maybe it is enough to say that global visual culture since the Dark Ages is looking, well, pretty impressive on this showing.

Those responsible for remodelling 'Le Grand Louvre' have been keen to adopt the rhetoric of radical Republicanism that accompanied the Louvre's first public opening, 200 years ago, in the heated political climate of post-Revolutionary Paris. When the Jacobins first threw open the Louvre ('monument to our glory and shame, witness to our servitude and barbarism') they did so in a spirit of defiant populism: what had been a private palace, a stronghold of the ancien regime, was henceforth to be public property. Mitterrand says that the remodelling of the Louvre has been undertaken in the name of 'the progress of liberty', but that phrase, however resounding, somehow lacks conviction. What is interesting about the new Aile Richelieu, and particularly its two most striking spaces, the enormous open courtyards that have been given glazed roofs and turned into sculpture galleries of Musee d'Orsay proportions, is how peculiarly nostalgic they seem for the golden age of absolutism. To walk through these vast, echoing chambers, where visitors are dwarfed by enormous relics of pre-Revolutionary statuary like Desjardins' Captives or Coustou's Horses of the Sun, is to become a termite surrounded by gigantic symbols of French military might and conquest.

The greatest spaces of the Aile Richelieu have been reserved, quite deliberately it would seem, for precisely those works of art that came most heavily under iconoclastic attack at the height of the Revolution because they celebrated the achievements and aspirations of ancien regime France. Now, although out of time and out of place, they still seem charged with a kind of nationalistic symbolism. They are the grand emblems of French cultural jingoism and what they, and the enormous spaces they occupy, say is this: no one cares about art or shows it so grandly, no one is so prepared to place art so heroically at the centre of civic life as us, the French.

Although the message might be boastful, it is true, and the rest of the Aile Richelieu proves the point in ways that are considerably less grandiose: the Oriental collections are installed in a maze of small but radiantly lit galleries in the basement; French sculpture of the Middle Ages, allowed to breathe as it never could before in more cramped conditions, is a revelation; Rubens's Marie de' Medici cycle, housed in a new purpose-built gallery, looks as mad and stunning as it ever has; the Assyrian palace sculptures look appropriately intimidating; the displays of the decorative arts, particularly the tapestries in the collection, are stunning. Visiting the Aile Richelieu is like visiting four or five different new museums - and the wonder of it is that there seem, at first glance at least, to have been virtually no misjudgements and certainly no disasters of hanging or installation. Posterity's verdict on Mitterramses I's greatest monument seems likely to be positive: it looks like pounds 780m well spent.

Of course, in this country, the idea of spending nearly pounds 1bn on an art institution could only emanate from the Raving Monster Loony Party. We seem keener on destroying art than placing it at the centre of civic life, as the recent Visigothic pronouncements of a certain Bow councillor on the subject of Rachel Whiteread's wonderful sculpture House would seem to indicate. By a peculiar coincidence, in the same week as the Louvre opened its new Aile Richelieu, London saw the opening of a new extension to the National Portrait Gallery. What a sad and sorry comparison it makes too. While the French spend heaven knows how many times the entire annual grant of the Arts Council on a tremendous new museum housing some of the greatest art in the world, what do we get? Several cluttered rooms designed to house works of such stunning triviality as Glynn Williams' carving of Noel Annan or Michael Frith's portrait, in watercolours, of Robert Maxwell. If the Channel tunnel ever does open, the traffic will all be going one way.

(Photographs omitted)