Gottfried Wilhelm Leibniz

Gottfried Wilhelm Leibniz was born in Leipzig on 1 July 1646, near the close of the Thirty Years' War, where his father Friedrich Leibniz was professor of moral philosophy. After his father died in 1652, the young Leibniz educated himself in his father's extensive library, mastering Latin and Greek before entering the University of Leipzig at age fourteen. In 1666 he published Dissertatio de Arte Combinatoria, proposing an alphabet of human thought and a formal calculus of reasoning (calculus ratiocinator), and after Leipzig declined to award him a law doctorate on account of his youth, he earned the degree at the University of Altdorf in February 1667. Entering diplomatic service for the Elector of Mainz, he traveled to Paris in 1672, where four formative years under the mathematical mentorship of Christiaan Huygens and exposure to the manuscripts of Blaise Pascal and René Descartes brought him to the frontier of European mathematics.

Between 1673 and 1676 in Paris, Leibniz developed differential and integral calculus independently of Isaac Newton. Recognizing the power of well-chosen symbols, in autumn 1675 he introduced the integral sign $\int$ (an elongated $s$ for Latin summa) and the differentials $dx$ and $dy$, leading to the derivative notation $\frac{dy}{dx}$ and compact rules such as $d(xy) = x\,dy + y\,dx$. He published the first printed account of differential calculus, Nova Methodus pro Maximis et Minimis, in Acta Eruditorum in 1684, followed in 1686 by De Geometria Recondita, which treated integration and the inverse relation between tangent and quadrature problems. Although Newton had developed his method of fluxions earlier (around 1665–1666), he had not published it, and from the late 1690s a protracted priority dispute arose between Newton, Leibniz, and their respective supporters in Britain and continental Europe; modern historical scholarship recognizes that both men arrived at calculus independently and that Leibniz's notation drove the rapid flourishing of analysis on the Continent.

From late 1676 until his death, Leibniz served at the court of Hanover as privy counselor, librarian, and historian to the House of Brunswick-Lüneburg. Alongside a vast correspondence across Europe, he designed the Stepped Reckoner — a mechanical calculator capable of all four arithmetic operations using a stepped drum — and systematically developed base-$2$ (binary) arithmetic using only $0$ and $1$, published in Explication de l'Arithmétique Binaire (1703). He played the leading role in founding the Electoral Brandenburg Society of Sciences (later the Berlin Academy of Sciences) in 1700, serving as its first president, and authored foundational philosophical works including Essais de Théodicée (1710) and Monadologie (1714). Leibniz died in Hanover on 14 November 1716.

Workplaces: Court of Hanover (House of Brunswick-Lüneburg), Berlin Academy of Sciences (Electoral Brandenburg Society of Sciences), Electorate of Mainz and Diplomatic Mission in Paris

Germany

Contributions, linked to the library