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Irritability, Sensibility, and Medical Philosophy

In the second half of the eighteenth century it was common to distinguish three general medical systems: mechanism, animism, and a third alternative which considered the basic physiological properties and operations as specific actions of the organic body or of vital forces. This third notion in particular was continuously developed and presented in such manifold ways that its common ground was not a precise concept anymore, but lay rather in its opposition to the other two systems. Haller’s contemporaries clearly conceived his position as a refutation of animism but besides that located it in various ways. Johannes Weise, for instance, doctoral candidate in Jena in 1772, defined the three medical systems as mechanism, animism and a third group consisting of the Hallerians and the Dutch school of Gorter, Gaub and their pupils.1 Apart from some small differences, the members of the third faction would agree perfectly in their descriptions of irritability and vital forces. Friedrich Casimir Medicus (1736–1808), court physician in Mannheim, drew a somewhat different picture in his oration On the Vital Force, held in 1774.2 In his view, there were two systems that divided the scholars. The first was animism, formerly supported mainly by Stahl and now by Sauvages in Montpellier and Whytt in Edinburgh. The second was mechanism, which had won almost universal recognition thanks to the works of Hoffmann and especially Boerhaave. Their theories were still taught in the Netherlands and Austria. With his concept of irritability, Haller had introduced some changes in this system, and most of the Germans, Italians and also some French and English had adopted his views. Haller’s position now was the predominant view of the mechanical philosophers and physicians. Both these systems, animism and mechanism – in either its Boerhaavian or Hallerian form – Medicus rejected, and he proposed a third, allegedly completely different explanation, based on the notion of a vital force that was neither part of the soul nor of the organic body. Still another version was offered by Ernst Platner (1744–1818), professor of physiology in Leipzig. In his reflections On Some Difficulties of the Hallerian System (1781) he maintained that Haller had considered Boerhaave’s explanation as too mechanical and Stahl’s as too metaphysical.3 Haller therefore created a new system that stressed the specific character of 175 Hubert Steinke animal nature and of corporeal properties. According to Platner, Haller’s view reigned in the German schools with almost unrestricted power and the whole science of pathology was restructured according to the notion of irritability. Weise, Medicus, and Platner represent the three common ways of situating Haller in the field of medical theories. They either aligned him with vitalist concepts or described him as a member of the mechanical school or as the father of a new system. Modern scholarship in its careful evaluation has merged these views and admits the validity of all three versions without playing off one against the other.4 Haller’s contemporaries, engaged in an actual debate about medical theory and practice, were less cautious and often interested in providing a particular account of his theories. It is the aim of this chapter to describe their different reactions and the general reception and transformation of the concept of irritability and sensibility in the eighteenth century. An exact survey, however, of the geographical and chronological dimensions of the adoption and appropriation of Haller’s ideas cannot be provided. The authors of the eighteenth century disagreed about the spread of ‘Hallerianism’ themselves. Medicus and Platner considered it as the dominating system in Germany and Italy but Ernst Gottfried Baldinger, a staunch Hallerian and professor of medicine in Göttingen, felt compelled to defend Haller against the criticisms of several German physicians.5 Only a few dogmas, he remarked in a plaintive tone, were shared by the physicians of this critical century. In Italy, scepticism about Haller’s novelties continued to be articulated after the more intense years of debate in the 1750s. Germano Azzoguidi (1740–1814), professor of medicine in Bologna, wrote to Haller in 1773 that several people, especially in Bologna, would refute the theory of irritability and follow Stahl or Boerhaave or argue in the manner of the Dutch vitalist Jan de Gorter.6 For the establishment of a detailed notion of the spread of Hallerianism, medical dissertations, lecture notes and handbooks should be studied in great numbers.7 Inevitably, the scope of this chapter has to be more modest. I have tried to identify representative modes of reception, appropriation and rejection and to determine some general shifts in physiology effected or affected by Haller’s theories. For such an approach, the traditional arrangement according to the three concepts of mechanism, animism and vitalism is still useful, although the lines between the systems will often turn out to be rather blurred. Mechanism: innovation and tradition Even before his treatise on irritability and sensibility, Haller had given rise to a discussion about his position on the mechanical system. In his edition of

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