"Spectacular Bodies", currently at the Hayward Gallery in London, is not an exhibition for the squeamish, nor for those of a nervous disposition. Here is an exhibition that sets out to unsettle and trouble us, to jar us into looking beneath the consoling familiarity of the outside of the body and at the disturbing, disordered moral void of its internal organs. Its purpose is not headline-grabbing sensationalism, but rather to shock us into thinking afresh about the close and intense historical relationship between the science of anatomy and those figural, aesthetic representations of the human body that we call "art".
The exhibition's project is to explore the ways in which, since the Renaissance, the job of understanding the human condition via the body has been shared between science and art. The curators, Martin Kemp and Marina Wallace, have succeeded brilliantly in catching and holding our attention, compelling us to give serious thought to the permeable boundary between medicine and art. They have succeeded in getting right under our skin.
Kemp and Wallace have raided the medical museums of Europe and crammed the Hayward Gallery with realistic two- and three-dimensional representations, laid on canvas, drawn, etched or modelled in wax, of the human body anatomised - its outer surfaces peeled back to reveal the viscera beneath, lovingly reproduced as objects of horrifying beauty. Indeed, although the subject matter is gruesome, beauty is very much part of these utilitarian medical creations, most of which were designed as teaching aids.
In the 18th century in particular, artist and surgeon collaborated to make sure that the anatom-ised body retained its huma-nity, thereby raising moral questions alongside the medical. The exquisite wax figures of female bodies with their viscera exposed are probably the most disturbing elements of this exhibition. Clemente Susini's Reclining Female Figure, laid on her back on a rumpled sheet, in bedroom pose, is unsettlingly erotic. Her legs, modelled in luminous and seductively smooth flesh-coloured wax, are elegantly angled, her head is thrown back, her long, plaited hair decorously arranged over her shoulders. But her belly has been slashed open, her inner organs laid out in magnificent wax detail for our examination. Andre-Pierre Pinson's Anatomy of a Seated Woman similarly combines the anatomically instructive with the familiar postures and sensibility of late 18th-century art. Pinson's pretty, dark-haired, naked young woman, her private parts concealed beneath coyly arranged drapery, takes up the pose of a nymph resisting the amorous attentions of a god or satyr. Seen from behind, she leans away from some unwanted attention and gestures to protect herself, a familiar figure of female modesty. But from the front, her outer flesh is cut away from the breastbone to the hips, her coloured-wax heart, lungs and intestines exposed.
This commitment to the aesthetic of the body alongside its analytical dissection is less unusual than we might think. From the 15th to the 19th century, the detailed lessons of dissection were an equally important part of the training of both the artist and the physician. In Cornelis Troost's large-scale painting The Anatomy Lesson of Professor Willem Roell, the bewigged surgeon fixes the onlooker's gaze as he points to the flayed knee joint of the corpse in front of him, instructing us on its mechanisms. To his left sits a well-dressed man, his gloved hand firmly grasping a cane. He, too, is animated by the exposed knee joint. The message is clear: the man with the bad knee expects the surgeon's hands-on exploration of anatomy to help cure his own complaint.
In a contrasting painting by Francois Salle, The Anatomy Lesson at the Ecole des Beaux-Arts, the professor of fine art points out the muscles in the wrist of a male model to a roomful of attentive young men. On the wall are large, coloured medical engravings of the human body, its parts and organs labelled for reference. Illuminated as the focus of the painting is a life-sized plaster figure of a flayed man - the technical term is an ecorche, a cadaver from which all the skin has been removed for closer study of the organisation of the muscles beneath. This figure has been transformed from anatomy specimen into potential art object by being placed in death, for plaster copying, in the pose of an antique discus-thrower. Such "artistic" ecorches were, we are told, something of a feature of the art academy classroom throughout the 18th and 19th centuries.
It is when we encounter the astutely chosen pieces of 20th-century art which form an integral part of this exhibition that we begin to take to heart the lessons learnt from Kemp and Wallace's carefully organised exhibits. Works by prominent contemporary artists, including Christine Borland, Marc Quinn, Bill Viola, Tony Oursler and Katharine Dowson, are distributed throughout the gallery, to be encountered at unpredictable moments as we follow the argument from anatomical drawings to catalogues of facial expressions, from the Royal Academy's anatomy classes to Charcot's public demonstrations of hysteria.
Dowson's Pia Mater, a giant backbone of illuminated blown glass, suspended in a darkened stairwell, becomes a vivid meditation on the human condition, on our physical fragility, beauty and mortality. In a similar way, so does Bill Viola's Science of the Heart. This installation juxtaposes a reassuringly tidy sickbed with huge, close-up video images of open-heart surgery, complete with amplified heartbeat, which judderingly becomes audible as the exposed heart is jolted into action. In another context, Viola's piece might smack of voguish sensationalism. Here, it belongs securely to a tradition that asks us to go beneath the comforting, contained morality of an aesthetically organised human experience, down to its precarious, fractured, fragile organic substance.
The exhibition provides the context: the aesthetic reassures and draws us towards an organic reality that we confront reluctantly, and with dismay. Yet here, as the surgeon knows, is the bottom line of mortality and, perhaps, also of morality. Standing in the darkness under the heart's insistent beat, we can recognise in Viola's installation the repeated struggle to make a collection of organs, fluids and mechanical operations cohere into meaning as "humanity", to locate the soul within the human body.
"Spectacular Bodies: the art and science of the human body from Leonardo to now" is at the Hayward Gallery, South Bank, London SE1 (020 7960 4242) until 14 January
Lisa Jardine is professor of Renaissance studies at Queen Mary and Westfield College, University of London. Her latest book, Global Interests: Renaissance art between east and west, is published by Reaktion Books (£25)