La Monadologie, in French

According to Wikipedia: "Gottfried Wilhelm Leibniz (1 July 1646 [OS: 21 June] 14 November 1716) was a German polymath who wrote primarily in Latin and French. He occupies an equally grand place in both the history of philosophy and the history of mathematics. He invented infinitesimal calculus independently of Newton, and his notation is the one in general use since then. He also invented the binary system, foundation of virtually all modern computer architectures. In philosophy, he is mostly remembered for optimism, i.e. his conclusion that our universe is, in a restricted sense, the best possible one God could have made. He was, along with René Descartes and Baruch Spinoza, one of the three greatest 17th-century rationalists, but his philosophy also looks back to the scholastic tradition and anticipates modern logic and analysis. Leibniz also made major contributions to physics and technology, and anticipated notions that surfaced much later in biology, medicine, geology, probability theory, psychology, linguistics, and information science. He also wrote on politics, law, ethics, theology, history, and philology, even occasional verse. His contributions to this vast array of subjects are scattered in journals and in tens of thousands of letters and unpublished manuscripts."