Early modern study of plants blossomed in a network of observation, exchanges, collaborations, and epistolary discussions. Following Baconian methodology, Dutch scholars combined the labor of listing and describing plants with botanical experimentation. This empirical approach was a suitable context for Descartes, who exchanged information and performed observations on plants in collaboration with Dutch experimenters. In this article, I focus on (1) the reception of a few botanical experiments of Bacon’s Sylva Sylvarum in Huygens and Reneri, with whom Descartes was in (...) contact, and (2) Descartes’ collaboration with Reneri. While performing observations on plants together, Reneri acquired Descartes’ theoretical framework (as it arises in his disputations) and influenced the latter with a Baconian approach to the study of living nature. This combination of experimental knowledge and a theoretical framework shaped a Cartesian study of plants, as it later surfaced in Regius and ultimately paved the way to a modern science of plants. (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)

One of the aims of Spinoza's Tractatus Theologico-Politicus is to vindicate the view that philosophy and theology are separate forms of enquiry, neither of which has any authority over the other. However, many commentators have objected that this aspect of his project fails. Despite his protestations to the contrary, Spinoza implicitly gives epistemological precedence to philosophy. I argue that this objection misunderstands the nature of Spinoza's position and wrongly charges him with inconsistency. To show how he can coherently allow both (...) that theology and philosophy employ independent epistemological standards, and that philosophy is epistemologically superior to theology, we need to step back from the immediate disputes to which the Tractatus is a response and examine a Ciceronian distinction on which Spinoza indirectly draws. As well as enabling us to vindicate Spinoza's position, it places his alleged naturalism in a new light and portrays philosophizing as a form of piety. (shrink)

Like many of their contemporaries Bernard Nieuwentijt and Pieter van Musschenbroek were baffled by the heterodox conclusions which Baruch Spinoza drew in the Ethics. As the full title of the Ethics—Ethica ordine geometrico demonstrata—indicates, these conclusions were purportedly demonstrated in a geometrical order, i.e. by means of pure mathematics. First, I highlight how Nieuwentijt tried to immunize Spinoza’s worrisome conclusions by insisting on the distinction between pure and mixed mathematics. Next, I argue that the anti-Spinozist underpinnings of Nieuwentijt’s distinction between (...) pure and mixed mathematics resurfaced in the work of van Musschenbroek. By insisting on the distinction between pure and mixed mathematics, Nieuwentijt and van Musschenbroek argued that Spinoza abused mathematics by making claims about things that exist in rerum natura by relying on a pure mathematical approach. In addition, by insisting that mixed mathematics should be painstakingly based on mathematical ideas that correspond to nature, van Musschenbroek argued that René Descartes’ natural-philosophical project abused mathematics by introducing hypotheses, i.e. ideas, that do not correspond to nature. (shrink)