[The vitalism of Paul-Joseph Barthez (1734-1806)].

In The Logic of Life (1970), Francois Jacob (1920- ), Nobel Prize laureate in Physiology or Medicine (1965), proclaimed the end of vitalism based on the concept of life. More than two decades before this capital sentence condemning vitalism was pronounced, Georges Canguilhem (1904-1995), a French philosopher of medicine, already acknowledged that eighteenth-century vitalism was scientifically retrograde and politically reactionary or counter-revolutionary insofar as it was rooted in the animism of Georg Ernst Stahl (1660-1734). The negative preconception of the term 'vitalism' came to be established as an orthodox view, since Claude Bernard (1813-1878) unfairly criticized contemporary vitalism in order to propagate his idea of experimental medicine. An eminent evolutionary biologist like Ernst Mayr (1904-2005) still defended similar views in This is Biology (1997), arguing that if vitalists were decisive and convincing in their rejection of the Cartesian model (negative heuristics), however they were equally indecisive and unconvincing in their own explanatory endeavors (positive heuristics). Historically speaking, vitalists came to the forefront for their outstanding criticism of Cartesian mechanism and physicochemical reductionism, while their innovative concepts and theories were underestimated and received much less attention. Is it true that vitalism was merely a pseudo-science, representing a kind of romanticism or mysticism in biomedical science? Did vitalists lack any positive heuristics in their biomedical research? Above all, what was actually the so.called 'vitalism'? This paper aims to reveal the positive heuristics of vitalism defined by Paul.Joseph Barthez (1734-1806) who was the founder of the vitalist school of Montpellier. To this end, his work and idea are introduced with regard to the vying doctrines in physiology and medicine. At the moment when he taught at the medical school of Montpellier, his colleagues advocated the mechanism of Rene Descartes (1596-1650), the iatromechanism of Herman Boerhaave (1668-1738), the iatrochemistry of Jan Baptist van Helmont (1579-1644), the animism of Stahl, and the organicism of Theophile de Bordeu (1722-1776). On the contrary, Barthez devoted himself to synthesize diverse doctrines and his vitalism consequently illustrated an eclectic character. Always taking a skeptical standpoint regarding the capacity of biomedical science, he defined his famous concept of 'vital principle (principe vital)' as the 'x (unknown variable)' of physiology. He argued that the hypothetical concept of vital principle referred to the 'experimental cause (cause experimentale)' verifiable by positive science. Thus, the vital principle was not presupposed as an a priori regulative principle. It was an a posteriori heuristic principle resulting from several experiments. The 'positivist hypothetism' of Barthez demonstrates not only pragmatism but also positivism in his scientific terminology. Furthermore, Barthez established a guideline for clinical practice according to his own methodological principles. It can be characterized as a 'humanist pragmatism' for the reason that all sort of treatments were permitted as far as they were beneficial to the patient. Theoretical incoherence or incommensurability among different treatments did not matter to Barthez. His practical strategy for clinical medicine consisted of three principles: namely, the natural, analytic, and empirical method. This formulation is indebted to the 'analytic method (methode analytique)' of the French empiricist philosopher Etienne Bonnot de Condillac (1714-1780). In conclusion, the eighteenth.century French vitalism conceived by Barthez pursued pragmatism in general, positivism in methodology, and humanism in clinics.