D Du Chesne, Joseph Hiro Hirai Center for Science and Society, Columbia University, New York, NY, USA Keywords Alchemy · Chymistry · Chemistry · Matter theories · Paracelsianism · Seeds · Universal medicine Introduction Born as the son of a French Huguenot in Gas- cogne, Joseph Du Chesne (1546–1609) was also known under a Latinized name of Quercetanus. He seems to have first studied surgery at Mont- pellier before working as a military surgeon. In 1574, he settled in Geneva and began to frequent the Paracelsian milieu, especially the circle of Theodore Zwinger (1533–1588) at Basel. Du Chesne then became an ordinary physician and a diplomatic agent to King Henry IV (1553–1610) of France around 1591. Du Chesne played the role of advocate for the community of “chymical” (alchemical/chemical) philosophers in the contro- versy between the traditional Galenists of the Paris faculty of medicine and the Protestant phy- sicians at the court of Henry IV. His primary concern was the defense of chymical art and its medical application. Upon publication of his treatise On the Matter of the True Medicine of Ancient Philosophers in 1603, Du Chesne was attacked by an anonymous work, entitled Apology for the Medicine of Hippocrates and Galen against the treatise of Quercetanus (Paris, 1603). The real author of this work was Jean Riolan the Elder (1539–1606), the dean of the Paris faculty of medicine. Du Chesne soon countered by pub- lishing the treatise, For the True Hermetic Medi- cine (Paris, 1604). Expounding at length the foundations of his natural philosophy and medi- cine, this treatise was widely read in Europe and exerted a considerable influence beyond the field of chymical medicine (Du Chesne 1603, 1604; [Riolan] 1603; Debus 1977, 1991; Gilly 1977–1979; Kahn 2004, 2007; Hirai 2005, 2010). Du Chesne’s Works and Significance In the theoretical part of his major work, For the True Hermetic Medicine, Du Chesne divides the physical world into two globes (superior and infe- rior). The former is composed of fire and air, the latter of water and earth. These four bodies are not regarded as the material causes of natural things but as their cosmological matrices and recepta- cles. This division closely follows the idea of Paracelsus, which was systematized by the Danish physician Petrus Severinus (1540/1542–1602) in his The Idea of Philosophical Medicine (Idea medicinae philosophicae) (Basel, 1571) (Kahn 2004; Hirai 2005, 2010). Du Chesne then © Springer Nature Switzerland AG 2021 D. Jalobeanu, C. T. Wolfe (eds.), Encyclopedia of Early Modern Philosophy and the Sciences, https://doi.org/10.1007/978-3-319-20791-9_488-1