Von der semiotischen zur diagnostischen Medizin: Die Entstehung der klinischen Methode zwischen 1750 und 1850 (review)

Diagnosis is a process whereby all sufferers and, especially, those who are designated as healers use their knowledge and past experience to make a series of judgments regarding the nature of the ailment in question. As the author of this most interesting but also narrowly conceived book acknowledges, diagnosis has moved to the center of modern medical action, mediating between patient history, clinical and laboratory information, bedside observation, and therapeutic decision-making. But how did such a complex practice develop? Hess’s thesis is that a critical shift in medical theory and practice occurred in Germany around 1800, transforming the traditional “prediagnostic” semeiology into our modern diagnostic thinking. In his view, the transition was not simply evolutionary, but implied a complete and radical reorientation in medical thought and behavior, including changes in nosology.

To “prove” his hypothesis, the author concentrates on developments in Germany—considered an intellectual entity—between 1750 and 1850. He has selected for analysis the writings of a handful of medical authors who published didactic texts or “Lehrbücher.” While somewhat informative, this approach bases its entire conclusions on an old-fashioned history of medical ideas—who said what when—without ever mentioning the cultural and professional contexts that may have been responsible for these constructions. More distressing, perhaps, is the author’s evident lack of interest in comparing and contrasting the postulated German conceptualizations with those occurring simultaneously in Paris, then the center of European medicine. The notion that German physicians rejected the superficiality of the French sensualist approach and focused on the drawbacks of Parisian hospital practice seems somewhat overdrawn.

Space allows only a brief sketch of Hess’s main arguments, which begin with an examination of Sydenham’s ideas, including his call for an empirically derived natural history of separate clinical entities. As a reflection of Baconian empiricism, the intention of the English Hippocrates was eminently practical: to improve the description of and distinction among various contemporary disease constructions. Moreover, Sydenham sought to link the most frequent clinical sequences to prevailing epidemic constitutions shaped by environmental factors.

The search for pathognomonic signs—distinctive characteristics defining the character of a particular disease—is said to have been adapted from the procedures of seventeenth-century botany. To accomplish such an aim at the clinical level, practitioners employed a traditional semeiology, embedded in humoralism. This approach focused on patient symptoms and signs, and was primarily designed to provide qualitative information about the ongoing individual dyscrasia and its prognostic implications.

From this rather fluid and individualized empirical approach, eighteenth-century physicians sought to obtain greater bedside certainty by redoubling their observational and classificatory efforts, but without any theoretical foundations or guidelines on how to proceed. More clinical observations only provided more data for more complex nosologies (Sauvages and Linné), thus contributing to the confusion. Hess acknowledges the role of prerevolutionary French sensualism in finally providing an ideology designed to frame subsequent clinical observations, but he makes the point that Pinel’s and Cabanis’s nominal nosologies were not designed to shape bedside judgments. In the view of contemporary German authors, nature could not be observed without frameworks derived from some general laws that could channel such perceptions.

Efforts linked to the introduction of Brunonianism into Germany before 1800 generated hope that medical knowledge could be brought together in some systematic fashion. ¹ The notion of a science of medicine endowed with Kant’s a priori qualities found widespread favor among the medical supporters of Schelling’s Naturphilosophie, including Andreas Röschlaub. ² A new concept of disease as a well-defined, evolutionary process, with its own particular causal chain responsible for all pathological manifestations, challenged practitioners to construct such entities and identify them through particular diagnoses. Hess argues that thenceforth disease ceased to be just a purely descriptive rendering of signs and symptoms, to become instead an...