One of the key themes of the Enlightenment was the search for universal laws and absolute truth that would help illuminate or reveal the inner workings of the universe. It is in such attitudes that we trace the origins of modern science and medicine. Conventional medicine follows conventional biology, conventional chemistry, and conventional physics in treating the material body-a complex, nonlinear system assembled from the same atoms and molecules that constitute nonliving objects such as computers and automobiles.The advocates of physicalism claimed there was no fundamental difference between living organisms and inanimate matter. Living phenomena could therefore be studied and explained with the methods and laws of physics.

Vitalists who postulated that living organisms had properties that could not be reduced to physics or chemistry and, therefore, biological phenomena could not be analysed with the concepts or methods of those sciences. Instead, vitalists claimed, to explain the nature of living phenomena one needed to apply such concepts as "vital force" and "vital fluids" to the analysis. Vitalism, as a response to the mechanistic models of the body that had dominated medicine, presupposed that organic beings (not machines) had self-organizing and transformational properties.

Not all eighteenth century scientists and physicians believed that such universal laws could be found, particularly in relation to the differences between living and inanimate matter. As Elizabeth Williams has shown :

From the 1740s physicians working in the University of Medicine of Montpellier began to contest Descartes's dualist concept of the body-machine that was being championed by leading Parisian medical 'mechanists'. In place of the body-machine perspective that sought laws universally valid for all phenomena, the vitalists postulated a distinction being living and other matter, offering a holistic understanding of the physical-moral relation in place of mind-body dualism. Their medicine was not based on mathematics and the unity of the sciences, but on observation of the individual patient and the harmonious activities of the 'body-economy'. Vitalists believed that Illness was a result of disharmony in this 'body-economy' which could only be remedied on an individual level depending on the patient's own 'natural' limitations.

Vitalism, according to the Merriam-Webster dictionary, is the doctrine that the processes of life are not explainable by the laws of physics and chemistry alone and that life is in some part self-determining. Vitalists contended that some vital factor, as distinct from physiochemical factors, was involved with "controlling" the body’s structure and function. Since the definition of vitalism emphasizes that its character is beyond the laws of physics (measurement), vitalistic mechanisms were outside of the defined parameters of modern science. In spite of its metaphysical nature, vitalism was still endorsed by many in romantic understanding of the healing power of nature in which the health prpofessional merely facilitates the innate healing power of the body.

Since vitalism is at the heart of alternative medical philosophy, and vitalism is perceived as metaphysics, the philosophy of chiropractic is not recognized by conventional medical science. So modern medicine considers alternative medicine as "unscientific" . Yet, in some ways, this debate has been superseded by the development of cellular and evolutionary theories, which indicated that living processes could not be satisfactorily explained either by Newtonian physics or by any non-material life forces. This fundamental metaphysical dispute in biology was eventually resolved with the conceptual development in biology of organicism, where life processes were explained by physiochemical and evolutionary instead of physical or teleological concepts

The ultimate explanation for human illness is now held to lie in the elementary cellular structures and their dysfunctions, as discoded amino acids in genetic processes. Conventional medical research has emphasized that genes are the responsible elements "controlling" health and disease. It is implied in the primacy of DNA theory that genes function as self-regulatory elements. Fundamental to this assumption is the requirement that genes must be capable of "controlling" their own activity. By definition, genes must be able to switch themselves on and off, as suggested in the concept of a cancer gene "turning itself on."

This conceptual change had a profound impact also on the development of medicine. The cellular theory of disease and its biochemical explanatory principle has displaced the physical and vitalistic approaches to human health and illness, and formed the knowledge base of 20th century medicine.

Where does that reductionism leave vitalism?

It becomes a part of the general critique of reductionism and the rejection of Enlightenment-style use of science as a knowledge/ power hegemony to assert a "single medical truth", or to elevate biomedicine in rank above any other medical modality. Pluralism has become accepted, and this change has seen a widening of medical theory from its current biological basis to include humanistic and social issues in medical thinking. Medicine is now oriented toward caring for human beings and it places medical consultation at the core of medicine. Medicine is seen as a form of interpersonal human activity taking place between a physician and her patient.

And yet, as this article shows, the decline of medical dominance has been associated with the rise of alternative and complimentary medicine. That opens up a space for vitalism. But what sort of vitalism?