Descartes on fermentation in digestion: iatromechanism, analogy and teleology.

Carmen Schmechel

doi:10.1017/s0007087421000819

Carmen Schmechel

Open Access

https://doi.org/10.1017/s0007087421000819

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Abstract

Fermentation is a cornerstone phenomenon in Cartesian physiology, accounting for processes such as digestion or blood formation. I argue that the previously unrecognized conceptual tension between the terms 'fermentation' and 'concoction' reflects Descartes's efforts towards a novel, more thoroughly mechanistic theory of physiology, set up against both Galenism and chymistry. Similarities with chymistry as regards fermentation turn out either epistemologically superficial, or based on shared earlier sources. Descartes tentatively employs 'fermentation' as a less teleological alternative to 'concoction', later renouncing the explicit use of the term, possibly to avoid chymical overtones. However, his continued use of analogies with fermentative processes in the natural world and in winemaking, coupled with a strong ontological commitment (the stance that the physiological processes are actual fermentations), leads to a reintroduction of natural teleology in his medical system, which I argue may be understood in an Aristotelian sense of 'simple necessity'. The paper reveals a more nuanced account of Cartesian fermentative medicine, delineating some of its tensions with regard to chymistry as they play out in the dynamics of fermentation and concoction, and linking the analogies to fermentation processes to the difficulties in erasing teleology altogether.

Highlights

Descartes tentatively employs ‘fermentation’ as a less teleological alternative to ‘concoction’, later renouncing the explicit use of the term, possibly to avoid chymical overtones. His continued use of analogies with fermentative processes in the natural world and in winemaking, coupled with a strong ontological commitment, leads to a reintroduction of natural teleology in his medical system, which I argue may be understood in an Aristotelian sense of ‘simple necessity’
Many scholars have pointed out the importance of fermentation for Cartesian physiology
Vincent Aucante notes in La philosophie médicale de Descartes that ‘the body is inhabited by various, more or less active fermentations’, which cover all the physiological processes of the organism, making fermentation ‘[l]e moteur des fonctions animales du corps’ and ‘la pierre d’angle de toute sa physiologie’