Abstract: This article explores the medical theories of the Dutch philosopher and physician Henricus Regius (1598-1679), who sought to provide clearer notions of medicine than the traditional theories of Jean Fernel, Daniel Sennert and Vopiscus Plempius. To achieve this, Regius overtly built upon the natural philosophy of René Descartes, in particular his theories of mechanical physiology and the corpuscular nature of matter. First, I show that Regius envisaged a novel partitioning of medicine, intended to make it independent in exposition (...) but conceptually grounded in natural philosophy. This served his overall purpose of making medicine a ‘clearer’ discipline. To this end Regius detaches the general notion of physiology as the study of the human body (which pertains to natural philosophy) from a medical physiology that concerns only health. Secondly, I show that Regius’s notions of health, disease, temperament and medicaments were the product of a Cartesian interpretation of traditional concepts, which was influenced by Santorio Santorio’s project of practicing medicine without occult elements. As a consequence, Regius’s classification of these notions is largely traditional. In conclusion, I show that Regius’s method of investigation in the area of natural philosophy consisted of a problem-solving procedure based on sensorial ideas. This approach can be traced back to Descartes, but was grounded on a purely empirical theory of knowledge, by which he rejected Descartes’s metaphysics. Regius’s order of exposition in natural philosophy and medicine, on the other hand, proceeds by definitions and divisions, and omits proofs. The reasons why Regius adopted this order were: 1) his rejection of Descartes’s metaphysical interpreta-tion of physics, and 2) his wish to emphasize the conceptual clarity and continuity of natural philosophy and medicine. (shrink)

In this article I discuss a particular aspect of the Dutch reception of the ideas of René Descartes, namely the use of his Traité de l’homme by Henricus Regius. I analyze the use that Regius made of the theory of the movement of muscles, passions, hunger, and more generally of the neurophysiology expounded by Descartes in his book (not printed until 1662–1664). In my analysis, I reconstruct the internal evolution of Regius’s neurophysiology, I illustrate its sources beyond Descartes (i.e., Jean (...) Fernel and Santorio Santorio), and I show that he was certainly acquainted with some of its contents as early as 1641 (when he used it with the mediation of Descartes), before relying on it—as variously discussed in secondary literature—in his Fundamenta physices (1646), when he appropriated from it without Descartes’s authorization. (shrink)

ABSTRACT. This essay addresses the interpretation of Descartes’ understanding of the mind-body relationship as a substantial union in light of a statement he makes in the Passions de l’âme regarding the role of the blood and vital heat. Here, it seems Descartes cites these corporeal properties as the essential dispositions responsible for accommodating the soul into the human fetus. I argue that this statement should be read in the context of certain medical texts with which Descartes was familiar, namely those (...) of Jean Fernel and William Harvey. Reviewing Fernel’s comments on substantial union, one finds that the soul joins the body on the basis of a celestial spirit that not only bears the vital heat, it also directs the generation of the body. Similar to Harvey, Descartes locates these properties in the blood itself, although, in contrast to Harvey, Descartes reduces these processes to matter and motion. Finally, I highlight the role this heat plays in Descartes’ embryological writing, contrasting it with that of Fernel. I conclude that although Descartes makes various comments supporting a reading of the mind-body relation as a substantial union, his physiological writings on generation and his idea of ‘life’ contradict this interpretation. -/- . (shrink)

The view that living beings as well as plant-based medicaments possess causal properties that are caused by the causal properties of their constituents, without being reducible to the combination of the causal properties of these constituents goes back to ancient thinkers such as Alexander of Aphrodisias and Johannes Philoponus. In the early modern period, this view was not only criticized by natural philosophers taking a reductionist stance; it was also criticized by Neo-Platonic thinkers such as Jean Fernel. One of (...) the relatively few early modern natural philosophers who adopted an emergentist position was Jacob Schegk. The present article discusses whether Schegk’s analysis of the structure of plants and medicaments offers the theoretical resources required to answer Fernel’s critique of the tradition going back to Alexander. In particular, it examines whether Schegk’s account of synchronic upward causation and diachronic downward causation could offer solutions to two interrelated problems identified by Fernel: the question of whether a mere aggregates of material particles could form a composite that possesses substantiality, not only accidental unity; and the question of whether multitudes of material particles could bring forth simple forms, whose existence seems to be presupposed by powers that cannot be ascribed to the constituents. (shrink)

In late Renaissance medicine, the example of digestion was frequently invoked to prove the elemental composition of the human body. Food was considered as being decomposed in its first elements by the stomach, and digested into a thick juice, which was assimilated by the liver and the body parts. Such a process points to the structure of the human body into four elements that are transformed into different types of humors during several stages of “concoction”. This chapter examines the Galenic (...) interpretation of digestion expounded by the French physician Jean Fernel (1497–1558) in his Physiologia (1567). In this treatise, Fernel states the body composition into elemental portions, while stressing the role of the “innate heat” as the physiological counterpart of the body’s essence or “substantial form”. He applies this view in his account of digestion, where he states that the conversion of food follows the rule of “mixture”. This chapter aims to explore how Fernel applies his interpretation of elements and innate heat to the process of digestion, as well as his sources in Galen’s De facultatibus naturalibus, Avicenna’s Canon and Aristotle’s Meteorologica. It first examines the role of the natural soul and its “nourishing” faculties in nutrition as a physiological function. It then considers the role of elements, humors and innate heat during the “concoction” of food in the stomach, liver and veins. (shrink)

The relation (ratio) between humankind and infinity. The Logos.