There is in the New Essays a prominent line of argument that Leibniz took to have remarkable scope. If it works, it sweeps away most of the mainstays of Locke’s metaphysics: atoms, vacuum, real space and time, absolute rest, inactive faculties, and the tabula rasa. It alone does not suffice to undermine the possibility of thinking matter, but it contributes support to that most important of Leibniz’s claims against Locke. Because it is so central to the project of New Essays, (...) I am going to focus mainly on the argument as it is employed there; doing so illuminates both the work and the argument. But Leibniz used it a number of times in letters and notes from roughly the same time period and it is related to a thesis in the Discourse on Metaphysics and letters to Arnauld. The argument invokes a distinction between abstract or incomplete entities and concrete or complete ones. Its premises are that atoms, vacuum, inactive substances, and other items on Leibniz’s list are homogeneous or uniform; that all things that are uniform or otherwise exactly alike are abstract; and that nothing abstract can be found in nature. (shrink)

The dissertation is a study the correspondence between G. W. Leibniz and Burcher de Voider that took place between 1698 and 1706. De Voider came to Leibniz as a Cartesian, but one who was disenchanted with the view due to its inability to provide a natural explanation of bodily change. I examine Leibniz's attempts to: disabuse De Voider of his lingering Cartesianism---in particular, his view that the material world is a substance constituted by extension alone; and convince De Voider of (...) the alternative metaphysic of body that he favors. The first part of the dissertation is concerned with the negative aspect of this project. A number of different arguments against the Cartesian view of material reality are discussed, along with a consideration of methodological differences that separate the two philosophers. In the second part of the dissertation, the views of Leibniz are explained. Here an account of material reality and bodily change emerges which is grounded in his categories of simple and corporeal substance, with the category of corporeal substance accorded a more prominent status than has been found in many recent studies. (shrink)