For as long as there has been a medical orthodoxy, there have been patients seeking alternatives to it, from mesmerism to homeopathy to reiki. So does that make them gullible, asks Roberta Bivins, or merely canny?

Richard Dawkins is upset. In particular, as the second part of his recent two part Channel 4 documentary The Enemies of Reason illustrated, he is irked by medical consumers' wilful tendency to rate experience and "anecdote" on a par with "evidence" and to seek out care and cures not validated by randomised controlled trials. And he is not alone. When Britain's Medicines and Healthcare products Regulatory Agency (MHRA) decided last autumn to allow homeopathic medicines to make specific therapeutic claims for the first time since 1968, they induced near-hysteria in some parts of the medical and scientific community. Aggrieved statements rapidly followed from the Medical Research Council, the Royal Society and the Academy of Medical Sciences, among others.

Both Dawkins and these expert protesters sense greed at the heart of alternative medicine, preying on a gullible public fallen from Enlightenment grace to superstitious irrationality. Given such orthodox practices as off label prescribing (where doctors, generally on the basis of anecdotal evidence and often encouraged by pharmaceutical companies, prescribe drugs for conditions other than those for which they were trialled and approved), not to mention concerns over the integrity of research funded by the pharmaceutical industry, one might be tempted to dismiss this as pots calling kettles black. But, as I discuss in my book, Alternative Medicine? A History , today's debates between proponents of a biomedical monopoly and practitioners (and consumers) of alternative healing practices continue a grand tradition of the modern medical marketplace, and one that demonstrates exactly the scepticism, experimentalism and broad-based inquiry that Dawkins advocates. The search for cures is, equally, a quest for truth - and it has long taken patients and practitioners alike to unexpected places.

For patients, medical "truth" has consistently been as subjective and pragmatic as the sensation of health itself; healers have proven more flexible in their definitions. On all sides, the rhetoric of objectivity and theoretical rigour has jostled with commercial and therapeutic pragmatism as deep as that of their clients. As one prominent medical advocate of acupuncture put it at a British Medical Association conference in 1968, "if snakes' blood and crocodiles' teeth produced cures", he would use them. Many doctors both before and since would have accepted that statement wholeheartedly. Indeed, a key feature of the medical marketplace since at least the 18th century has been its appetite for novelty, whether fostered by innovative ideas in science and technology, or imported from other cultures increasingly accessible to West.

³ÉÈËVRÊÓƵ

Throughout the 18th century (and beyond), such novelty-seeking was driven by a paucity of genuine cures. While medical knowledge was expanding, medical efficacy had stalled, remaining entrenched in older approaches characterised by bleeding, purging, puking and the rest. These treatments aimed to correct imbalances in the body's four constituent humours. Ideally (in other words, as experienced by the wealthy), these treatments were dramatic, holistic, highly individualised, sensitive to patients' emotional states and social and physical environments - and generally ineffective, when not actively harmful. Across Western culture, both physicians and their consumer foils, hypochondriacs, were stock figures of fun, the former for their greed and the latter for their gullibility.

While there have been "quacks" for as long as there have been profits to be made from illness, self-consciously "alternative" medicine as it exists today materialised only once an orthodoxy had been established to which it could be contrasted. In the West, such an orthodox medical profession crystallised in the 19th century, when elites began to assert their rights to control the practice of medicine, limiting it to those with particular forms of training and accreditation. Moreover (despite the claims of many sceptics and some historians), alternative systems of medicine do not spring up like toadstools, parasitical on more orthodox practices. They emerge in times of change and of new ideas - moments of paradigm shift.

³ÉÈËVRÊÓƵ

The late 18th century was exactly such a moment. In culture, new ideas of the social contract and of enlightened rationality were unsettling the established order, and breeding calls for radical reform (as manifested in the American and French revolutions). New discoveries in science made it possible to imagine a universe of subtle fluids, acting physically but also metaphysically on grosser matter, including the human body. The two major medical systems to emerge de novo in this period - homeopathy and mesmerism - drew on these ideas, using the newly defined powers of magnetism and electricity, and the still-mysterious chemistry of "dephlogisticated air" (oxygen) to root themselves in the soil of science, while challenging a medical profession that they presented as hidebound and corrupt. And it is no coincidence that these most popular "alternatives" were also systems of medicine that allowed most fully for consumers to be their own doctors, whether through the wide availability of medical manuals and kits for the home (homeopathy) or through an emphasis on the ability of charismatic amateurs to heal through pure force of will (mesmerism).

The 19th century also saw striking changes, although until the rise of bacteriology at its end, its medical revolutions were principally organisational and professional. While the engines that powered increases in the efficacy and persuasive power of mainstream medicine - anatomy, disease specificity, even ideas of germs and contagion - were well-integrated into the intellectual repertoire of the day, their systematic deployment in medical education, public health provision and practice was groundbreaking. At the same time, people's expectations of themselves and their society were also rising; discourses of uplift and self-improvement thrived. This too was fertile soil for alternatives: homeopathy and mesmerism flourished, and orthodox medicine fumed.

Orthodox medicine also fought back, with some overall benefits. In the burgeoning medical press, best exemplified by the rabble-rousing new journal, The Lancet , calls to arms against "the quacks" strengthened professional identity and amplified calls for reform within the profession. At the same time, individual practitioners assimilated their rivals by stealth. With patients groaning under the strain of "heroic medicine" - bled until they fainted, dosed with mercury until their teeth rattled in their jaws - sensible "allopaths" adopted the gentler treatments of their homeopathic competitors. Surgeons experimented with mesmeric trances, at least until the advent of easier (if more dangerous) chemical anaesthesias. And the orthodoxies of other cultures too were sampled, most notably acupuncture.

Meanwhile, mesmerists and homeopathists formed associations, founded journals, built colleges and hospitals, factories and dispensaries. Crucially, alongside such empire-building, they nurtured their grass-roots: just as orthodox medical knowledge was adopting the exclusive language of science, shutting consumers out of the literature and devaluing their experiences of their own bodies, alternative practitioners were inviting them in, reconfirming their importance in the medical encounter, and marketing medicines to be used at home. Only more recently has biomedicine begun to accept the vital importance of involving patients, educating them and offering care when and where they can best benefit from it.

³ÉÈËVRÊÓƵ

While the different proponents of medical systems struggled to distinguish themselves from the competition, producing the heated debates that characterised 19th-century medicine, middle-class consumers blandly opted to "suck it and see", sampling homeopathy, mesmerism, acupuncture, hydrotherapy and the myriad other options clamouring for their attention while pursuing the mainstream cures of orthodox practitioners. With rather fewer options, the poor were no less pragmatically pluralist; patent medicines abounded, but never erased traditional remedies, and every new avenue opened by professional healers, whether orthodox or alternative, rapidly thronged with health-seekers - in much the same way that patients today enrol in clinical trials, besiege their GPs, Google for cut-rate pharmaceuticals (with or without a prescription) and still find time to visit their local acupuncturist or Ayurvedic spa.

As consumers, we remain pragmatic, torn between conservatism and novelty seeking; healers who can cater to such paradoxical tastes will flourish. Thus we see great interest in the traditional, time-tested but to us still exotic practices of Chinese medicine, reiki and Ayurveda. As a society we are increasingly risk-averse; the very power of biomedical treatment brings with it greater iatrogenic risk. If thalidomide - given to mothers to alleviate their morning sickness - did not teach us that lesson dramatically enough, we would surely have taken the hint from ER , House and their broadcast brethren. So we seek milder regimes, ones without direct risk, sometimes even at the cost of immediate relief. And, as in the 19th century, when industrialisation first invented "stress" (they called it "neurasthenia") and exposed the dark side of technological innovation, alternatives such as homeopathy, naturopathy, aromatherapy and traditional herbal medicines feed our craving for a different, simpler and more natural life.

Even biomedicine's spectacular successes contribute to our taste for alternatives. As Westerners ceased to die from the great epidemics and the grinding childhood diseases - and as we became wealthy and inactive - chronic diseases and diseases of older age took over as the major causes of ill health. And they are far less tractable to the miracle cures and major surgeries of hospital medicine; time-intensive, often degenerative and incurable, they linger expensively, frustrating patients and doctors alike - and create the same climate of dissatisfaction that so favoured the first flowering of alternative medicine.

Under these circumstances, doctors and other biomedical professionals who deplore the popularity of alternative medicine might wish to ask themselves: what exactly do we lose when health-seekers explore their options? Few give up orthodox medicine altogether, or even see their pluralism as reflecting on the value of biomedicine. As patients and consumers, individuals seeking out therapeutic substances and devices have always done so with one eye on a cure and the other on their wallets. Healers too - and particularly those on the expensively honed cutting edge of biomedicine - must balance ideals and outlays. Looking in two different directions at once, is it any surprise that consumers and professionals alike have sometimes walked off precipices, or run enthusiastically towards what are ultimately therapeutic dead ends, bickering all the way? And yet, despite - and sometimes because of - its rivals and its setbacks, biomedicine thrives, adapts and adopts. Perhaps choice, with all its challenges, is healthy after all.

³ÉÈËVRÊÓƵ

Roberta Bivins is Wellcome lecturer in the history of medicine at the Cardiff School of History and Archaeology. Her book Alternative Medicine? A History is published on October 4 by Oxford University Press, ?14.99.