509 Descartes’ Bio-medical Study Of Plants Early Science and Medicine 23 (2018) 509-529 Early Science and Medicine 23 (2018) 509-529 * Herzog August Bibliothek, Lessingplatz 1, 38304 Wolfenbüttel, Germany; University of Bucharest, 1 Dimitrie Brandza Str. 060102 Bucharest, Romania. Descartes’ Bio-Medical Study of Plants: Vegetative Activities, Soul, and Power Fabrizio Baldassarri * Herzog August Bibliothek, Wolfenbüttel/University of Bucharest fabrizio.baldassarri@gmail.com Abstract This article addresses René Descartes’ problematic interpretation of vegetative activi- ties within his mechanistic programme for explaining all living operations. Initially, Descartes illustrates nutrition and digestion by means of the analogy between animals and hydraulic machines. His account has a glaring weakness: he fails to supply a func- tional explanation for vegetative operations. Several botanical notes collected in the Excerpta anatomica reveal Descartes’ later attempt to bridge this lacuna. His study of plants (1) provides him with material for an improved specification of vegetative activi- ties, (2) helps to shape a mechanical vegetative power that regulates bodily constitution and growth, and (3) allows him to isolate a class of living beings. While a more thorough explanation of nutrition, digestion, and growth in mechanical terms surfaces, Descartes proposes plants as a suitable model organism to explain vegetative activities. Keywords Descartes – botany – vegetative activities – vegetative soul – organic growth – nutrition 1 Introduction In his early physiology Descartes (1596-1650) has a difficult time in dealing with the entirety of living functions, despite the claim to the contrary he made to © Koninklijke Brill NV, Leiden, 2018 | doi:10.1163/15733823-02356P06 www.brill.com/esm