REGIUS, Henricus.

First edition of this work of Cartesian medicine and natural philosophy by the Dutch physician Henricus Regius (1598-1679), which posited an “improved” system of Cartesianism. According to Heirs of Hippocrates ‘the book is very rare and is not found in the major medical bibliographies,’ and declares the woodcut showing magnetic forces (p. 131) to be ‘of special interest.’ The Fundamenta ‘created something of a sensation when it appeared because the author departed from his adherence to Cartesian doctrine and, as a result, was denounced by Descartes’ (Heirs of Hippocrates, 305).

Perhaps the key point of departure between Regius and Descartes was Regius’s emphasis on the mind as organ: the brain as the originator of sense and motion within the body, i.e. operating like any other mechanical part, thus going against Descartes’ dualism of immortal mind (soul) and mechanical body. In the final chapter, De Homine (On Man), there are some remnants of the idea – included in Regius’s original draft, sent to Descartes for approval, but removed to placate him –  that natural reason cannot alone ‘preclude the possibility that the human mind is a mode of body’ (Tad Schmalz, “The Curious Case of Henricus Regius” in The Oxford Handbook of Descartes and Cartesianism (Oxford: 2019), pp. 437-438). This assertion went directly against Descartes and was made worse by Regius’s attempt – which did survive into this first edition – to point out that Scripture ‘undoubtedly’ makes clear the immateriality of the mind/soul: ‘In taking a fideist stand on these issues, Regius was staking out his own distinctive – and controversial – opinion’ (Schmalz, p. 438). Indeed, Regius immediately afterwards states that the mind, at least when in the body, is organic (p. 246). Regius’s assertion concerning the mind is also accentuated here as part of his study of anatomy, with woodcut illustrations of the dissection of organs including the brain and various vascular systems. These were part of his attempt to separate anatomy and medical science from purely physiological study and include it within a system of natural philosophy. He covers nutrition, diet and digestion, circulation, generation of semen and menstruation, the formation of foetuses and pregnancy, cognition, respiration, and sight. Regius’s work also contains theses on hydraulics, optics, magnetism and planetary physics.

This book soured the relationship between Regius and Descartes. Regius had earlier defended Cartesianism against the attacks of the theologian Gisbertus Voetius (1589-1676), who managed to have Cartesianism banned at Utrecht, where Regius was teaching it, in 1642. However, Descartes warned Regius against publishing the Fundamenta Physices and publicly disowned it, while also accusing his former ally of plagiarism. The final straw was Regius’s publication with one of his medical students of a broadsheet disputation detailing the anti-Cartesian theses, to which Descartes published his own broadsheet response in 1648, the Notae in Programma Quoddam or Notes on a Certain Programme (Schmalz, pp. 440-441).

The contemporary annotator, who makes one observation to the text concerning clouds, otherwise offers up a number of prayers and praises to God and the Virgin Mary on the rear pastedown.