Jean Le Rond d'Alembert
A towering Enlightenment intellect who co-piloted the Encyclopédie, devised a key principle of physics, and gave his name to a Parisian street.
1717–1793 (age 76)·French mathematician·Birthday: November 16
Biography
Jean Le Rond d'Alembert entered the world as a foundling, left on the steps of the Parisian church of Saint-Jean-le-Rond, which gave him his name. Raised by a glazier's family, his brilliant mind was his true inheritance. He became a leading mathematician and physicist, formulating d'Alembert's principle, which cleverly simplified problems of motion in dynamics. His fame, however, is inextricably linked to the Encyclopédie. Alongside Denis Diderot, he served as its co-editor, contributing the seminal 'Preliminary Discourse' and countless articles on science. This work was a bomb thrown at the foundations of old-regime thinking, championing reason and secular knowledge. Though he eventually withdrew from the project under pressure, his role was decisive. A fixture of Parisian salons and the French Academy, d'Alembert embodied the ideal of the philosophe, using rigorous science in the service of human progress.
#1 When Jean Was Born
The biggest hits of 1717
Jean's Life & Times
The world at every milestone
1717Born
1722Started school
1730Became a teenager
1733Could drive
1735Could vote
1738Turned 21
1747Turned 30
1757Turned 40
1767Turned 50
1777Turned 60
1787Turned 70
1793Died at 76
Key Achievements
- Co-edited, with Denis Diderot, the Encyclopédie, the central publication of the French Enlightenment.
- Formulated d'Alembert's principle in mechanics, a foundational concept for relating forces to motion.
- Developed a solution to the one-dimensional wave equation, known as d'Alembert's formula.
- Made significant contributions to the study of partial differential equations and the theory of complex numbers.
- Was elected Permanent Secretary of the French Academy of Sciences, a position of immense intellectual influence.
Did You Know?
He was the illegitimate son of a famous salon hostess, Madame de Tencin, and an army officer, but was abandoned as an infant.
He turned down an invitation from Frederick the Great to become president of the Berlin Academy, and later refused a similar offer from Catherine the Great of Russia.
The Rue d'Alembert, a street in the 14th arrondissement of Paris, is named after him.
He was a talented musician and music theorist who wrote several entries on the subject for the Encyclopédie.
“The true system of the World has been recognized, developed and perfected.”
