Failures of Mechanization: The Vegetative Power and Early Cartesians, Regius, La Forge, and Schuyl

René Descartes’ mechanization of living activities lays bare a glaring lacuna that concerns vegetative functions, such as nutrition, generation, and growth: his cardiovascular framework affects any exhaustive explanation of these activities. When he mentions a mechanical vegetative power in his 1641 correspondence with Henricus Regius, this definition is unspecified, although it may be correlated to a few posthumous bio-medical notes. Descartes’ mechanization of the vegetative soul remains puzzling. Early Cartesian scholars were thus obliged to fill this lacuna to produce a more exhaustive physiology. In this chapter, after reconstructing Descartes’ own position in L’Homme and in his manuscripts, I explore the positions of Regius, Louis de La Forge, and Florent Schuyl, who dealt with Descartes’ medical texts and physiological doctrine through various perspectives. Yet, while building a mechanization of vegetation upon Descartes’ philosophy, their interpretations of a mechanical vegetative power uncover shortcomings, weaknesses, and failures.