Why is Jean Le Rond d’Alembert remembered as an important Enlightenment thinker?

Jean Le Rond d’Alembert is remembered as a pivotal Enlightenment thinker due to his dual contributions as a pioneering scientist and a leading Philosophe who championed the sovereignty of reason over dogma.12

His significance is defined by several key roles:

• The Encyclopédie: As a primary editor and contributor, he helped shape this monumental work, which aimed to organize and popularize human knowledge. He authored the Discours préliminaire, a landmark essay that presented a unified view of the interrelationship of all branches of knowledge.1
• Scientific Advancement: He made fundamental contributions to mathematics and physics, most notably through "d’Alembert’s principle" in dynamics and his work on partial differential equations.3
• Intellectual Leadership: As a member and later permanent secretary of the French Academy, he used his influence to promote intellectual independence and support the cause of the Philosophes.42
• Rationalist Advocacy: He stood for tolerance, free discussion, and the replacement of traditional religious authority with a social morality based on human reason and scientific inquiry.12