Don't ask 'why', ask 'how'

I want you to imagine that I'm a Venusian. I've just got out of my rocket. I can speak English. And I'd like you to try to explain to me how to tie a shoelace. OK? You know the kind of game - one of those tests for I'm not sure what. We art critics are set them all the time. We're always finding ourselves having to describe things that are, for all practical purposes, indescribable. We have a go. But we know that if our words do manage to instil an accurate picture in a reader's mind's eye, it's the merest fluke.

Often this doesn't much matter. The reader can get by without a total visualisation of the object in question. A rough idea will do. What's needed is the sort of account that conveys effects, feelings, the experience, the notion, the sense. Points can be made effectively, even when the look of the thing itself remains quite vague.

But what if there isn't really a sense?

At the Liverpool Tate Gallery at the moment you can see sculptures by Richard Deacon. They come with the overall title New World Order, a form of words that seems too burdened with ironies - remember the last war but one? - to be useful. And I may as well admit at the outset that I feel pretty blank about these works; don't hate them by any means, wouldn't try to step in if I heard somebody praising them, am perfectly content to share a planet with them and with their fans; just don't get it. So I'm going to have to describe them. Damn.

Deacon is about 50. He was one of those sculptors who - as the phrase is - came to prominence in the Eighties, part of a movement that was known, engagingly, as the New British Sculpture. It included such others as Tony Cragg and Bill Woodrow. It was New because, after a stretch of dominance by conceptual and performance work, it put the focus back on objects.

Deacon made his mark then chiefly with lumbering 3-D collages of industrial stuffs, and large, loopy bows of plywood. Wood, metal and textile were notable ingredients. There were hints of the figurative. The show in Liverpool is all from the Nineties. The artist is still operating as a - his word - "fabricator". The leading materials now are wood and plastic. The figurative has gone. I'm not doing very well, am I?

Some basic features. Deacon has never much used straight edges. His shapes are curvy or bobbly. The curvaceousness suggests, not living forms, more a Scalextrix track. The bobbliness is similar to that when something has been heated up and expanded irregularly. These objects emphasise their constructedness. They are the opposite of seamless. Their joins are visible. If they're glued together, too much glue is applied, and it seeps out. If there's a bolt connection, it's over-bolted.

But often they have to be described in negatives. You wouldn't exactly call them abstract. They're too bitty to become pure forms; the identity of their constituent materials is too obtrusive. But you wouldn't call them weird or jokey objects either. They don't have explicit enough real- world associations to arouse that sort of reaction.

Here, they come in three sizes. There are some large, monumental wooden constructions - tubes of open latticing, kind of lobster-pot oesophaguses, that writhe and wind in convoluted loops. There are smaller, standing- up, roughly person-sized pieces, made of bent wood, and moulded transparent plastic, and rubber, and cardboard; but as for their shapes, my descriptive powers fail. And then there are objects smaller still, sitting around on the floor, blobs and flats and tube-y and boxy things and - leave alone delineate - with a few of them I couldn't even guess what they were made of, or whether they would be solid or squashy or hollow to the touch. At any rate, I touched one, and it wasn't at all what I expected.

Now, there were definitely moments when I thought "This is all going to come alive". The first sight is very exciting, when you glimpse one of those gigantic wooden writhers through a doorway, and it seems to promise something of overwhelming size and complexity (though it turns out this promise was mainly a glimpse effect). And another loopy one called Laocoon is good to look at, because its convolutions seem to be at the very limit of what you can get your mind round - ie you can just about work out that it doesn't contain a knot (though I guess someone with high spatial skills might realise this at once).

And there are nice opportunities for the tactile imagination, especially some pieces of smooth, polished wood. There's one which is rather like the lid of an old loo seat that's been buffed and buffed to an almost fragile thinness, and lies on the floor as if it were a pool of spilt water.

But I think I liked that one just because it had a metaphorical charge. And probably what one should look for in Deacon's work is the precise opposite - the way it so cleverly eludes any kind of identification, the way it produces objects that don't quite chime and don't quite jar, that stand there as plausible but as yet unrecruited candidates for the world.

Which, as an idea, sounds fine, doesn't it? And I got that feeling off one piece at least, something called Float (quite simple, futile to try and evoke). But mostly the impression was more like this. Here's this guy in his enormous studio, filled with all kinds of collected stuff and with manufacturing facilities ready to hand. Sometimes he has a big idea. But mainly he's kind of pottering, putting a and b together, trying out process x on material y, thinking that's quite interesting, and then noticing some accidental by-product on the floor, and thinking that's quite interesting, too.

As an embodiment of the act of making and the spirit of invention, Deacon's work is exemplary - presumably inspiring, also. It would be the ideal show to take a school art class round. The objects are excellent drawing- models. They're excellent incitements to creativity. They would be just the thing for design students, as well. They're like exercises that ask to be developed, incorporated, taken up and on somewhere. Many of the little things are in a series called "Art for Other People", and I think that's what it means: for further use.

All the stress is on the how. Perhaps it's a generational thing to find that not enough. Certainly, this is work that makes you feel the passage of time and taste, and how different Eighties sculpture was from what's come to prominence in the Nineties. The creative agenda is quite changed. Now it's hot on whats and whys. It's all a matter of knowing exactly what you're up to, articulate meanings, explicit real-world references. You may get a bit of mystery, but that's an extra. And in those terms, Deacon's work looks rather beached. What's it about? Well, er, not quite the right question, not if you expect it to be answered anyway, rather than just savoured.

And no doubt with the British art of the Nineties, things have swung too far into articulacy. You get to a point where works hardly need to be seen or made at all, as a full description is both perfectly feasible and all you need; and where artists are positively encouraged to talk and think like drones from a cultural studies department. There's a strong case for not knowing too clearly what you're up to. I note that the Tate's accompanying Deacon literature is almost completely meaningless. I don't mean jargonised, I mean as artspeak used to be - without any literal sense whatever. At the present moment, that's quite an encouraging sign.

'Richard Deacon: New World Order', Tate Gallery, Albert Dock, Liverpool. Until 16 May. Closed Mon (0151-709 3223)