Visual Arts: Four hundred years of stripping off on doctors' orders

"Last week," Jonathan Swift wrote, "I saw a woman flay'd, and you will hardly believe, how much it altered her Person for the worse." Well, how would you put it? We have insides, and we can hardly ignore this important fact, but it's very hard to find the right way of feeling about it. Any attitude you take is likely to seem too sanguine or too hearty, too fastidious or too fascinated, too objective or too sadistic. For that reason, it's a subject very proper for artists to get their teeth into.

"The Quick and the Dead: Artists and Anatomy" may well be the most interesting show to be seen this year. This is a South Bank Touring Exhibition, which has started its run at the Royal College of Art in London, going on to Coventry and Leeds, and it's curated by the RCA's Professor of Drawing, Deanna Petherbridge, with a keen eye for beauty, instruction and astonishment. The theme is interpreted broadly. Every sort of meeting between art and anatomy is represented, from roughly the Renaissance on.

Among the 150-odd exhibits - pictures and models - you find the textbook demonstrations of medicine and biology, figure analyses from the life- class, pictures of dissection-scenes, mythical stories with anatomical subjects (the Flaying of Marsyas, Ezekiel's Valley of bones), constructions of ideal proportions, memento moris, and anatomical fantasias which seem to have no obvious purpose. But if this sounds like a heady melange, then what's clear at once is that here categories aren't clear. In this gallery of body-works, observation, inquiry, aesthetics, allegory, comedy, pathos, the grotesque and the erotic are all mixed up.

There are big names, including such well-known art-science crossover artists as Leonardo and Stubbs. You find the old masters at practice, Rubens doing a page of muscles, Caracci doing a page of feet (who says hands are the hardest things?). And the theme turns up some excellent surprises, like Jaques de Gehn's exquisite pen studies of a frog or a little picture by Nicholas Hilliard of a skeleton on a dark ground with the nervous system flashing round it like lightning. But the journeymen artists, who did the medical body-maps for Vesalius and his heirs, are no less absorbing. And it's with these works, whose use is notionally scientific, that a contemporary viewer is in for the most shocks.

We have an idea of normal anatomical illustration: a more or less neutral display of the body's parts and functions, where the body is shown as an ideal system, in no relation to any particular body alive or dead. It's a working model - dehumanised if you like, but hardly human enough for one to feel that. And what's startling about their 16th- and 17th- century equivalents is how this norm isn't observed, doesn't seem to be a norm at all. What you find, in image after image, is the anatomised body embracingly humanised.

Dissected, dismembered, opened-up, stripped to the muscle or the bone they may be, but these physical specimens remain living, personalised, socialised bodies. They stand in landscapes. They co-operate with the anatomist's work by helpfully displaying their own dissections to the viewer, holding open skin flaps to reveal viscera, fanning out an array of tendons. They catch our eye, and adopt poses that are heroic or modest or sexy (a man with his genitals sliced and labelled). Skeletons kneel in prayer. Corpses seem to swoon with pleasure or writhe in pain. And this, remember, is textbook stuff.

It's hard to catch the tone. You're not sure whether it's a kind of joke, or whether it's a practical matter of showing how a living body works, so best to show it alive, or whether the story-telling impulse just can't be restrained even here. They're fantastic pictures, but perhaps not simply fantastic if one thinks of devotional images of Christ and the martyrs showing their wounds, and surgery before anaesthetics, and public executions in which the condemned often stayed alive and talking during evisceration, and general worries about the impiety of dissection (though it's good, too, to understand God's handiwork). What these pictures never let you forget is that to get anatomical knowledge, real bodies have to be cut up.

The temptation for us, well-schooled in the Surrealist virtues, is to find these pictures disturbing, and to like them for that. Wrongly, I think. Not that they're untroubled, but they're broad-minded about this. Depicting bodies from one point of view doesn't exclude, for these artists, all the other ways of feeling about them; and giving the anatomical body consciousness allows one to do this with a certain ease. But this ease doesn't last. And one of the many stories this very rich exhibition tells is about the birth of the "disturbing". It's a matter of different responses getting separated out, so that when they come together, it jolts. It seems to happen around the middle of the 18th century.

Gautier d'Agoty's dissections in colour mezzotint are really the first pictures where you feel something is up, the first occasion you want to talk about aestheticisation. The gorgeous colours and tactile tones are at odds with the detailed body analysis. The artist's response is divided. He's shocked himself by the way his fractured specimens can look so lovely, and relishes it. You have this sense even more strongly with the extraordinary illustrations to an Anatomy of the Human Gravid Uterus by Jan van Riemsdyck - and here I think even those with the most hearty appetite for the disturbing will start to wobble a little.

Pregnancy is an abiding source of interest throughout the show, and clearly it produces intriguing Russian-doll images. A body is opened up to disclose another little body inside it. The mother stands before us, and the belly peels back like the petals of a flower, or flips off like the lid of a pot. But in these beautifully high-finish red-chalk drawings, Van Riemsdyck incites the most extreme contraries. The mother's body is clearly a specimen for display, just a torso cropped at the chest and thighs. At the same time it's erotic flesh on a bed, the legs splayed for sex as much as birth, with the pudenda stressed by being pointedly hidden by a little book. It's also dead meat on the slab: in another picture the thighs are sawn through and the stumps presented full-frontal. After these sensations, the dull neutrality of Gray's Anatomy, established in the mid-19th century, seems a wisely calming measure.

It's around then, with the firm specialisation of scientific illustration as a non-artistic genre, that the show pretty well stops. But not quite. In the last 15 years there's been a lot of anatomy-based art - art that revels in the body's dangers or tries to assert the body's rights against clinical classifications. A dozen or so examples are included here (by Kiki Smith, Cindy Sherman, Robert Gober, Marc Quinn and others) to put a contemporary gloss on all the history.

But it's rather a token gesture, partly because there's so much of this work that it could make a large show by itself, partly because it then seems arbitrary to exclude almost all the earlier modern art about the body (one Max Ernst collage excepted), but mainly because all the subjects the recent stuff is dealing with are very thoroughly addressed by the rest of the show. It's still absorbing the shocks felt a couple of centuries ago. And although one would hardly wish to return to Vesalian medicine, this exhibition can't but incite some nostalgia for its vision, where bodies whole and dissected, quick and dead, weren't subject to an absolute apartheid - just so long as it stays a vision, and doesn't come to live next door.

To 24 Nov, RCA, London SW7 (0171-590 4444); then on tour