What is matter made of, and why do physical bodies resist motion? These questions were at the center of scientific debate in the seventeenth century, when modern physics was taking shape. This dissertation explores how the polymath Gottfried Wilhelm Leibniz developed his answers to these problems across his career. By examining both well-known texts and previously unpublished manuscripts, the study reconstructs how Leibniz moved from early atomistic ideas to a dynamic account of matter. On this view, matter is not merely extended or inert, but possesses an inner tendency to resist motion and change. The dissertation shows how this idea gradually emerged from Leibniz’s engagement with texts, experiments, and scientific institutions. It highlights his engagement with the ideas of well-known figures such as Hobbes, Gassendi, Huygens, and Newton, as well as with a range of lesser-known authors who played a crucial role in shaping these debates. The study also offers a fresh perspective on Leibniz’s complex relationship with the mechanical philosophy and the Aristotelian tradition, showing how he creatively reworked inherited concepts to strategically position himself within the philosophical and scientific landscape of his time. More broadly, the research sheds new light on the evolution of early modern natural philosophy and on its relationship with metaphysics in the seventeenth century.
Omar Hraoui obtained both his Bachelor’s degree (2019) and his Master’s degree (2022) in Philosophy from the University of Milan. In 2022, he completed a research internship at the Center for the History of Philosophy and Science at Radboud University Nijmegen. In September 2022, he began a PhD in a joint degree programme between Ca’ Foscari University of Venice and Radboud University Nijmegen, working on a dissertation on Gottfried Wilhelm Leibniz’s theory of matter. He has published on seventeenth-century natural philosophy, with a particular focus on theories of matter and on the relationship between corpuscular and mechanical philosophies and the Aristotelian tradition.