Be careful what you wish for, the saying goes, because you might get it. Would Marcel Duchamp, submitting his urinal to an exhibition in 1917 in order to show that art is anything we want it to be if we know how to look, or Joseph Beuys' insistence that everybody is an artist, be happy with where so much contemporary art has ended up? What once seemed so fresh and iconoclastic often now seems like a series of tired nostrums.
To mark the end of Liverpool's year as European Capital of Culture, Tate Liverpool is presenting what it hails as "a groundbreaking exhibition inspired by ideas and proposals from people across the city". The title, The Fifth Floor, refers to a level in the gallery that does not, in reality, exist. Through a series of artist-led workshops with local groups, Tate Liverpool asked what sort of exhibition the people of the city wanted. One wag suggested that they should "take away all the art and replace it with people, all kinds of people, eccentric people, to emulate what was there..."
Instead, they bundled up a ragbag of proposals and invited a collection of international artists to "interpret" them. This sounds like art by committee, though Tate Liverpool would, no doubt, claim that The Fifth Floor provides an imaginary, democratic space for encounter, collaboration and creativity, where views can be exchanged, decisions and responsibilities shared, and where we can each rethink the role of artist, curator and audience, roles that much of this work suggests are interchangeable. No need for three years at art school, then.
Over and over again, work blurs the boundaries, as that old cliché goes, between artist and spectator, whether in Peter Liversidge's neon "room" that frames the viewer; Olivier Bardin's rows of nine leather armchairs, in which the gallery visitor can sit and become "part of the work"; or the Dutch artist Rineke Dijkstra's photographs and videos made with Liverpool high-school pupils and in local nightclubs. It is as if the modern subject has become so self-obsessed and uncertain of his or her identity that only be uttering the mantra, "I observe myself, therefore I am", can they apparently have any sense of self in this chaotic and uncertain world.
Art that in some way does not "mirror" or "reflect" the viewer hardly seems to exist here; it proliferates through everything, from tenantspin's Community TV Channel interviews, to Paul Rooney's film of aspiring comics telling each other stories in an old cinema, and Tino Sehgal's tiresome exchange with a local person pretending to be a Tate Liverpool assistant (a rehash of a similar work shown recently at the ICA) about the current economic climate.
And however much fun the group of toddlers had in the baby disco in the interactive, modular "film-set" space created by the Swedish art collective International Festival, will this translate one day into any of them walking into a gallery to look seriously at a Titian, or even a Kiefer or Viola? The most satisfying piece here is by Xijing Men, a collective of three artists from China, Japan and South Korea. Inspired by the oral histories from their respective countries, they have produced a series of drawings that were used by a local youth theatre to create storyboards for performances reminiscent of a Javanese shadow-puppet show.
That public galleries have to appeal to a wide range of people and justify their funding goes without saying, but what a contrast this empty show makes when compared with the beautiful and, when I attended, almost empty William Blake exhibition, on the ground floor. There could not be a more graphic contrast between this and the spurious claims of The Fifth Floor to illustrate how far we have come from Blake's belief in the importance of a spiritual art for a material age, an art potentially redemptive of humanity, where we can "see a world in a grain of sand/ And a heaven in a wild flower".
To 1 February (0151-702 7400)