ARTS: EXHIBITIONS: It's all in what the eye cannot see

Anish Kapoor has brought a new solemnity to the Hayward's galleries, filling them with his distinctive sculptural voids, encased in shiny, pristine surfaces

IN RECENT YEARS, the Hayward Gallery has occasionally, and generously, given all its spaces to a contemporary sculptor. Richard Long, Julian Opie and now Anish Kapoor have had this privilege. The Hayward is a difficult space for sculpture, but Kapoor has used the galleries with more ingenuity than his predecessors. He hasn't overcome the grimness of the outside sculpture courts, and the corridor between the two top galleries remains an intractable problem, yet the Hayward makes a sympathetic showcase for Kapoor's elusive art.

Like Long and Opie, Kapoor is not a sculptor with a particular interest in fashioning original three-dimensional forms. All three of them depend on their capacity for display - making large-scale artistic interiors of the kind that look so good in modern museums. In this area, Kapoor has had the invaluable help of the architect, Claudio Silvestrin, who deserves some of the credit for the success of the show. What he gives us is not exactly an installation. It's more an architectural redesign of all the Hayward's interior spaces. He could do nothing with the sculpture courts, where pieces stand or fall on their own merits, and in the awkward corridor Kapoor looks suspiciously like an airport artist. But everywhere else, Silvestrin has blocked off entrances and exits, built new walls and altered the shape of rooms to give a feeling of new and pristine solemnity.

This fits precisely with Kapoor's ambitions. He wants to show us things we have not seen before and, with his invention of "the void" as a sculptural concept, does so. He's concerned to have surfaces so pure that they repel the hand, however much our instinct is to explore the insides of his mysterious sculptures by tactile means. Some pieces are covered with pungently coloured pigment. Others, in stainless steel, are as polished as a mirror. Sculptures made from fibreglass and wood have a miraculous faint yellowy-snowy whiteness, nacreous and virginal, as though marble had been reinvented for a new century. Smoothness suits Kapoor's character as an artist. Whenever he has previously used rough material - sandstone or limestone, for instance - the sculptures have failed. This new, polished finish is more relevant to his talents.

As for the solemnity, Kapoor (born in Bombay in 1954, educated at Hornsey and Chelsea Schools of Art) was first noticed in the early 1980s, when he was an artist-in-residence at the Walker Art Gallery in Liverpool, and had his first show at the Lisson. Everyone remarked that his sculpture had Indian roots, although its banal, floor-based forms were the common currency of British postgraduate sculpture departments. His work always reminded us of shrines or temples. A metaphysical tendency seems to have grown since that time. Certainly it was pronounced when Kapoor showed at the Venice Biennale in 1990. Eight years later we are being asked to regard him as a major religious artist. This is the purport of the embarrassingly overblown essays in the exhibition catalogue. It's easy to resist the cloudiness of such writing. Still, it remains true that Kapoor asks us to look at something that we cannot understand. Often, we can't grasp a meaning because it's in part of a sculpture that's almost invisible, while the general outline of the sculpture is as plain as can be. This is the interior which he calls a void. He can't manage it with stone, but in wood and fibreglass pieces, he does a soft circular burrowing down from the surface, or a harder rectangular burrowing, so that you cannot see what's in the part that he has excavated. The eye loses its grasp, and there's a sensation of emptiness, all the more so because there is so little trace of the work of the human hand. Kapoor has been showing works of this sort for a few years now. I've never seen anything quite like them before, and am intrigued.

The deadening fault of these sculptures is that the interesting part of them resides in illusion. Everything apart from the void, which you cannot properly see, is ordinary. Kapoor cannot create strong three-dimensional shapes of his own, so he goes for three alternatives. His outlines are circular or spherical, so that composition looks after itself. Or else they are box-like. Or else they are upright slabs. The boxes are the best and contain the most charming "voids". The slabs are disappointing, they lack personality. The uncomfortable truth is that they might have been made by any one of a dozen British sculptors in the last decade or so.

Stainless steel pieces, all circular, reflect the observer. When they are convex and embedded in a wall, you see yourself distorted and upside down. The only truly moving work is on the bottom floor. In a room constructed by Silvestrin, a huge, round dome-like structure hangs from the ceiling, open at the bottom. You can stand underneath and look upwards at its unfathomability. Perhaps Kapoor and Silvestrin ought to do some architectural work together - at Greenwich?

! Anish Kapoor: Hayward Gallery, SE1 (0171 960 5226), to 14 June.