Irritating Experiments: Haller's Concept and the European Controversy on Irritability and Sensibility, 1750-90 (review)

Owsei Temkin, whose solid scholarship allowed him to be perfectly at ease in the history of premodern, early modern, and modern medicine, pointed long ago in this same journal to the classical roots of the question of irritability.¹ In Galen's work, irritability stood at a major intersection: if the soul and nature are the two sources of motion in the human body, and if the soul implies both sentience and nerves, whereas nature functions in the absence of both sentience and nerves, how can we explain actions that seem to require a form of bodily intentionality without any involvement of sentience or nerves? A plausible explanation of the phenomenon of irritability had therefore to account for the interrelationship of three physiological factors: muscular motion, the faculties of the soul, and the operations of nature. Temkin's article addressed issues pertaining to seventeenth-century physiology, and to Francis Glisson in particular. So what was new in the eighteenth century? To cut a very long story short, we might say there was a fresh notion of the mind, a notion not based any longer on the classical division into soul and nature, and not even on the Cartesian division into consciousness and body, but on a tripartite division into mind, life, and body. Another new element was a different theological climate, inclining toward occasionalistic solutions to avoid the least suspicion of pantheism. By and large, the general attitude of the scientific community was also different because, for the first time, the mechanical hypothesis became plausible. The combination of all these factors, together with a series of important discoveries and experiments, revealed in dramatic fashion that the polarization between mechanism and animism was too simple and too crude. It was as a result of the growing complexity of the eighteenth-century medical panorama that more-or-less compact fronts broke into a panoply of medical sects: post-Boerhaavian mechanists, reformed Stahlians, Hallerians of various creeds, and vitalists of all kinds with very specific notions of vital principles—Paul-Joseph Barthez's principe vital, Johann Friedrich Blumenbach's Bildungstrieb, John Hunter's vital principle.

Hubert Steinke meticulously chronicles and analyzes this complexity of theorizations and experimental strategies about life. At a time when much historiography dallies with questions of jargon etiquette and philological correctness, Steinke reassures us that Haller was doing "experimental physiology," and that we are allowed to say so. The reader might think that this is not really a great achievement—but in fact, the point is worth being made. In the past few years, historians of science have been rapped on the knuckles because of improper and anachronistic uses of some very special words: do not say "science" when it is "natural philosophy," do not say "chemistry" when in fact it is "alchemy," and finally, do not say "experimental physiology" when it is "anatomy." Significantly, all this obsessing about linguistic precision betrays residues of positivism disguised in philological garb, for when one asks at what point in time one is supposed to use the words under examination, the answer is always the same: in the nineteenth century—that is, when natural philosophy became science and experimental physiology was born. This amounts to saying that nineteenth-century science is the reference point for historians of science who wish to establish what science is. To say this is to say that science is, after all, what positivism said it was. Or maybe the whole linguistic hysteria is simply a frigid reaction to a certain extreme gusto for analogizing that is characteristic of postmodern tendencies, so that history of science has become more and more an inflexible censor of linguistic mores, and less and less an understanding reviewer of complexity. In any case, in demonstrating that Haller has every right to...