Gottfried Wilhelm Leibniz

Gottfried Wilhelm Leibniz (1646-1716) was, with Descartes and Spinoza, one of the leading rationalists, and perhaps best known for his view that the universe is ultimately composed of "simple souls" called monads. He is also celebrated for his discovery of the infinitesimal calculus at about the same time as Newton. He is also well known among non-philosophers for his view, expressed for example in his Theodicy, that "this is the best of all possible worlds"--which was lampooned by Voltaire in the character of Dr. Pangloss in his Candide.

Leibniz was also virtually unique among pre-20th century philosophers in that he wrote mostly short essays and letters, and only one book-length work. Perhaps his best-known essays are "Discourse on Metaphysics" and "Monadology."