Antony Gormley is a terrific artist. The practice of rotating modern artworks on the Fourth Plinth in Trafalgar Square is a splendid and stimulating one. And yet somehow, the decision that Gormley will be the next artist whose work will be displayed is disappointing (see page 15).

For Gormley's proposal is that the plinth be occupied for 100 consecutive hours, 24 hours a day by members of the public who have volunteered to stand on it for an hour at a time. He says that this will “reflect on the diversity, vulnerability and particularity of the individual”. But the same is true for the thronging crowds in Trafalgar Square. This is not visual art, it is voyeurism: it has more in common with Big Brother than with big ideas.

This is a shame because it is Gormley who has set the standard for public art. The Angel of the North is so loved that Gateshead Council threw a party to celebrate its tenth birthday at the weekend. He hoped that its wings, tilted forward, would create a feeling of embrace, and it is so magnificent that it is the people of the North East who have taken it to their hearts.

Last year's Event Horizon, too, was a thoughtful work. Thirty-one life-sized sculptures were displayed on top of London buildings. Eerily, the spectator became aware of them, standing high up as if they were watching. It was a clever way of exploring the experience of being watched, by CCTV and by our millions of fellow citizens.

Gormley is popular and accessible. From Crosby to Calabria, his sculptures have been moving meditations in three dimensions. The people on the plinth will be three-dimensional too, but the art in which they participate will, sadly, fall flat.