This chapter examines the use of vegetal analogy in late Renaissance physiology through the case of the German physician Daniel Sennert. It is centered on Sennert’s explanation of generation, in particular the transmission of life through the vegetative soul within the seed, as developed in his early works on medicine and alchemy, the _Institutionum medicinae libri V_ and _De chymicorum…liber_. This chapter first summarizes Sennert’s account of generation and the seed’s “formative force” according to Aristotle and Galen, as well as (...) his appraisal of the medical debates on the origin of the seed’s soul and form. Then, the next part explores Sennert’s own interpretation of the origin of forms, for which plant physiology served as a common denominator of his medical, alchemical and theological inclinations. Finally, this chapter considers how Sennert attempted to harmonize his reasoning with the Paracelsian account of generation, seed and life. (shrink)

In the early modern age, two causal models are clearly identifiable: action at a distance—a typical Renaissance paradigm, widespread among thinkers involved in natural magic and seventeenth-century Neoplatonists—and action by contact, on which both the Aristotelians and the Cartesians agreed. Pierre Gassendi too seems to endorse the motto: ‘Nihil agit in distans nisi prius agit in medium’ [Nothing acts at a distance unless it acts through a medium]. In this essay, it will be shown that a third causal model exists, (...) according to which material bodies are surrounded by ‘atmospheres’ of effluvia or qualities, which spread within a circumscribed ‘sphere of activity’, whose extension is peculiar to each body. In particular, it will be shown: what the third causal model was like, from an ontological point of view, that is, how it centred on the concepts of effluvium and spiritus, or qualitas; what this model was like, from a gnoseological point of view; how it was theorized by... (shrink)