Gottfried Leibniz 1646 – 1716

Gottfried Wilhelm Leibniz was a 17th-century German polymath and one of the leading rationalist philosophers of the early modern period. He invented infinitesimal calculus independently of Newton and developed binary number theory, foundational to modern computing. His metaphysics is built around the concept of monads, simple substances that constitute reality, and the principle that this is the best of all possible worlds. He made significant contributions to logic, mathematics, theology, and law, and corresponded with most leading thinkers of his age. Leibniz's philosophical optimism was famously satirized in Voltaire's Candide.

Gottfried Wilhelm Leibniz (1646–1716) was the most ambitious universal scholar of the seventeenth century. Born in Leipzig, he served the courts of Mainz and Hannover for most of his career, traveled across Europe on diplomatic missions, and corresponded with virtually every major intellectual of his age. He invented the differential and integral calculus independently of Newton — the priority dispute between them poisoned the last years of his life — and made fundamental contributions to logic, jurisprudence, theology, and engineering.

Leibniz's mature metaphysics is set out in the Monadology (1714) and supporting works. The world is composed of an infinity of monads — simple, immaterial, individual substances, each of which is a unique perspective on the universe. Monads have no real causal interaction with one another; they are coordinated by a divinely instituted pre-established harmony. Leibniz's logical and metaphysical principles — sufficient reason, identity of indiscernibles, predicate-in-subject — constitute the most rigorously worked-out version of seventeenth-century rationalism.

Leibniz's New Essays on Human Understanding (composed 1704, published 1765) is a sustained paragraph-by-paragraph reply to Locke. His Theodicy (1710) gave the modern philosophical vocabulary the term and the project — justifying God's permission of evil in the best of all possible worlds. He died in Hannover, neglected at the end of his life, in 1716.