Albrecht von Haller (1708–1777), the Swiss polymath, is best known in the history of medicine for his concept of irritability and sensibility. His orations De Partibus Sensilibus et Irritabilibus, delivered in 1752 and published in 1753, caused a European controversy about the function of nerves and muscles and about the properties of the living body in general. They were translated within two years into French, English, German, Italian and Swedish, and have since then been considered a classic of medical literature. No general history of medicine skips Haller's contribution to physiology or 'animal economy', as it was often called in these days. Haller claimed to have proven by animal experiments that only the muscular fibre possesses the ability of contraction, which he called irritability and which was responsible for movement. From this property he strictly distinguished sensibility, responsible for sensual impression and inherent only in the nerves and the parts furnished with nerves. Thus he challenged the traditional, mechanical – mainly Boerhaavian – model on three main points. First, Haller postulated a force inherent in the muscular fibre and independent of the nerves and the soul. Second and partly as a result of this, he separated – conceptually and physically – the two properties of movement and sense perception. Third, and again in part resulting therefrom, he established a strict correlation between structure and function, not on the level of corpuscules or elementary particles, however, but on the level of compound structures, ie. the muscular and nervous fibres. Several well-balanced, general descriptions of Haller's concept have been published. Maria Teresa Monti and especially François Duchesneau have furnished detailed and illuminating conceptual analyses of his theory. Duchesneau, Roselyne Rey and others have located it within the general development of physiological models and have worked out its differences from the theories of leading mechanists (Boerhaave, Caldani), animists (Whytt), semi-vitalists (Fontana) and vitalists (Bordeu, Barthez, Wolff, Blumenbach, Hunter). The notions of irritability and sensibility of many minor authors have been presented in brief summaries by Jörg Jantzen and some other scholars.
The contributions of Duchesneau and Rey reflect the epistemological turn in the history of biological sciences, initiated by George Canguilhem. Like Canguilhem, they focus on the structure of concepts rather than on the . . .