Gottfried Wilhelm von Leibniz ( (July 1, 1646 – November 14, 1716) was a polymath who made important contributions to a vast number of fields, including mathematics, physics, philosophy, probability theory, linguistics, psychology, ethics, theology, law, history and diplomacy. Some fields he created: differential analysis, symbolic logic, and computer science. His writings are scattered in learned journals, tens of thousands of letters, and unpublished manuscripts. He published only a single book in his lifetime, The Theodicy (1710). To this day there is no complete compilation of his writings.
Leibniz maintained that the actual world is selected from a number of possible worlds in the act of creation, in accordance with the Principle of Sufficient Reason: that there must be a reason, to be sought in its moral or physical perfection, why it is thus and not otherwise. This doctrine had important implications in his treatment of symmetries: it followed, according to Leibniz, that there could be no two things exactly alike (the Principle of Identity of Indiscernibles), hence that atomism is false; and that neither space nor time can have any existence independent of matter, and hence that Newton’s absolute space was a fiction. He proposed in its place that space was nothing more than the system of relations of bodies, and time only the ordering of events, but that even these relations were not truly fundamental. Rather, at the fundamental level there exist only unities (monads), each distinguished by providing a unique series of representations. The coherence among these representations was to ground ‘well-founded’ relations (such as spatial and temporal relations).
Leibniz corresponded with the cleric Samuel Clarke over Newton’s physics and philosophy of space and time, published as the Leibniz-Clarke Correspondence (1723). He had earlier been involved in an acrimonious dispute with Newton’s followers over his alleged plagiarism of the calculus.