In this article I discuss a particular aspect of the Dutch reception of the ideas of René Descartes, namely the use of his Traité de l’homme by Henricus Regius. I analyze the use that Regius made of the theory of the movement of muscles, passions, hunger, and more generally of the neurophysiology expounded by Descartes in his book (not printed until 1662–1664). In my analysis, I reconstruct the internal evolution of Regius’s neurophysiology, I illustrate its sources beyond Descartes (i.e., Jean (...) Fernel and Santorio Santorio), and I show that he was certainly acquainted with some of its contents as early as 1641 (when he used it with the mediation of Descartes), before relying on it—as variously discussed in secondary literature—in his Fundamenta physices (1646), when he appropriated from it without Descartes’s authorization. (shrink)

While some seventeenth-century scholars promoted natural history as the basis of natural philosophy, they continued to debate how it should be written, about what and by whom. This look into the studios of two Amsterdam physicians, Jan Swammerdam (1637–80) and Steven Blankaart (1650–1705), explores natural history as a project in the making during the second half of the seventeenth century. Swammerdam and Blankaart approached natural history very differently, with different objectives, and relying on different traditions of handling specimens and organizing (...) knowledge on paper, especially with regard to the way that individual observations might be generalized. These traditions varied from collating individual dissections into histories, writing both general and particular histories of plants and animals, collecting medical observations and applying inductive reasoning. Swammerdam identified the essential changes that insects underwent during their life cycle, described four orders based on these ‘general characteristics’ and presented his findings in specific histories that exemplified the ‘general rule’ of each order. Blankaart looked to the collective observations of amateurs to support his reputation as a man of medicine, but this was not supposed to lead to any kind of generalization. Their work alerts us to the variety of observational practices that were available to them, and with what purposes they made these their own. (shrink)

ABSTRACTJacques Rohault is often considered to be one of the most meticulous followers of Descartes. Despite this, Rohault’s natural philosophy lacks much of the metaphysical bulwark that typifies Cartesian treatises of the seventeenth century. Instead, Rohault’s work, as well as his popular weekly meetings, strongly emphasized rigorous observation and experimentation. Traditionally, this emphasis on experiment over metaphysics is seen as a pragmatic omission to avoid the perils associated with censorship and Cartesian metaphysics. However, I find that the lack of explicit (...) metaphysics has real consequences that play out in the role Rohault assigns to experimentation. To show this, I highlight several areas where he adopts a broad experimental methodology even though Descartes explicitly rejects the relevancy of experiment on metaphysical topics. I place special emphasis Rohault’s extensive experiment on the void. In short, Rohault’s experimentation was designed to prove, through experimental mea... (shrink)

In 1675, Burchard de Volder (1643–1709) was the first professor to introduce the demonstration of experiment into a university physics course and built the Leiden Physics Theatre to accommodate this new pedagogy. When he requested the funds from the university to build the facility, he claimed that the performance of experiments would demonstrate the “truth and certainty” of the postulates of theoretical physics. Such a claim is interesting given de Volder’s lifelong commitment to Cartesian scientia. This chapter will examine de (...) Volder’s views on experiment and show that they are not Newtonian or inductivist, as is sometimes claimed. While de Volder thinks we need deductive reasoning from first principles to provide evidence of the certainty of the content of our physical theories, he also contends that we need experiment to provide evidence of the certainty of the existence of the particular bodies those theories discuss. This approach to experiment is based on a distinction between rational certainty and the certainty of material bodies in the actual world. While this account is deeply influenced by Descartes, it is importantly different than Descartes’ distinction between absolute and moral certainty. De Volder’s “Cartesian Empiricism” is best understood as a continuation and further development of a long tradition of teaching through observation at Leiden. (shrink)

In the past decade, several Descartes scholars have gone on record claiming that, for biological purposes, Descartes likely accepts the practical scientific necessity of the existence of “physical natures,” even while his official substance-mode ontology and his characterization of matter in terms of extension do not license the existence of physical natures. In this article, I elaborate on the historical context of Descartes’s biology, the “practical scientific necessity” just mentioned, and argue, contrary to other interpretations, that Descartes does offer a (...) philosophical justification for the existence of physical natures, albeit not by appeal to the categories of substance and mode, or matter as such, but by appeal to our “nature” as a union between mind and body. (shrink)