Early whyttScience and Medicine the idea 18-4-5 of power(2013) 381-404 [55] ISSN 1383-7427 (print version) ISSN 1573-3823 (online version) ESM Whytt and the Idea of Power: Physiological Evidence as a Challenge to the Eighteenth- Century Criticism of the Notion of Power Claire Etchegaray University of Paris X (Paris-Nanterre-La Defense)* Abstract In An Essay on the Vital and Involuntary Motions of Animals, Robert Whytt maintained that the muscular motions that perform the natural functions of the organism are caused by an immaterial power. Here we consider to what extent the philosophical criticism of power urged by Locke and Hume may jeopardize his thesis, how his response mobilizes the resources of the Scottish experimental theism and whether he makes an original use of such resources. First, we examine various pieces of experimental evi- dence from which Whytt infers the need to evoke this power, before showing how they prompt him to stand by the immaterial power in the face of the empiricist criticisms. Following this, we explore the link Whytt makes between power and agency, in particu- lar comparing his thought with Locke’s. Lastly, we examine his work in the light of Hume’s criticism regarding the question of whether a power may be felt. Keywords active principles, agency, animism, William Cullen, experimental method, feeling, Albrecht von Haller, David Hume, Francis Hutcheson, John Locke, materialism, nerves, power, Thomas Reid, Scottish Enlightenment, soul, sympathy, Robert Whytt Whytt’s Medical Project in the Essay In 1744, dissatisfied with the widespread theories of cardiac motion and respiration, Robert Whytt began to write the Essay on the Vital and other Involuntary Motions of Animals.1 In the volume that he eventually pub- * Institut de Recherches Philosophiques (IREPH), University of Paris X (Paris-Nanterre- La Defense), 200 avenue de la République, 92001 Nanterre, France (claire.etchegaray@ u-paris10.fr). [56]382 claire etchegaray lished in 1751, he used the hypothesis of the action of an immaterial power present in the nerves to explain the motions by which bodily func- tions are performed.2 He opposed the materialism and mechanism that, according to him, Albrecht von Haller’s conception of the fibre might entail. Julien Offray de la Mettrie had translated Haller’s annotation to Herman Boerhaave’s Institutiones medicae into French in 1743 and dedi- cated L’homme machine to the physician of Göttingen in 1748. In the Es- say, Whytt alleges that the opinion that there is an inherent property of contraction in the muscular fibre paves the way for an unknown mate- rial and mechanistic cause of animal motion. He takes this opinion, de- fended by Haller, to be a “refuge of ignorance.” But couldn’t this accusation have been applied to Whytt himself: couldn’t the appeal to an immate- rial power have been taken as a “refuge of ignorance” too? Intending to shed light on the anthropological implications of Whytt’s position, in addition to his contribution to the history of neurophysiology, scholars’ interest has focused on three main areas: his metaphysical presupposi- tions, the sociological background to the concept of sensibility and sym- pathy and the coherence of his Newtonian approach.3 1) Robert Whytt, An Essay on the Vital and Involuntary Motions of Animals (Edinburgh, 1751, second ed. with corrections and additions, Edinburgh, 1763). 2) Roger Kenneth French, Robert Whytt. The Soul and Medicine (London, 1969). 3) On the history of neurophysiology, see Georges Canguilhem, La formation du concept de réflexe aux XVIIe et XVIIIe siècles (Paris, 1955), 101-106; Eugenio Frixione, “Irritable Glue: The Haller-Whytt Controversy on the Mechanism of Muscle Contraction,” in Harry Whitaker, Christopher U.M. Smith and Stanley Finger, eds, Brain, Mind and Medicine (Marquette, Birmingham, St. Louis, 2007), 115-24; and Max Neuburger, The Historical Development of Experimental Brain and Spinal Cord Physiology Before Flourens (Balti- more and London, 1981). On the metaphysical theses, see John P. Wright, “Metaphysics and Physiology: Mind, Body and the Animal Economy in the Eighteenth Century Scot- land,” in M. A. Stewart, ed., Studies in the Philosophy of the Scottish Enlightenment (Oxford, 1990; reprinted 2000), 251-301; and John P. Wright, “Substance versus Function Dualism in Eighteenth Century Medicine,” in John P. Wright and Paul Potter, eds., Psyche and Soma. Physicians and Metaphysicians on the Mind-Body Problem from Antiquity to Enlightenment (Oxford, 2000; reprinted 2007), 253-54. On the sociological background, see Christopher Lawrence, “The Nervous System and Society in the Scottish Enlighten- ment,” in Barry Barnes and Steven Shapin, eds., Natural Order. Historical Studies in Scientific Culture (Beverly Hills, 1979), 19-40. On the Newtonian approach, see François Duchesneau, La physiologie des Lumières. Empirisme, modèles et théories (The Hague, Boston and London, 1982), 171-215..