Jean le Rond d'Alembert was an influential French mathematician, physicist, and philosopher born in 1717. He is best known for his work in the field of mathematics, particularly for co-editing the famous Encyclopédie alongside Denis Diderot. d'Alembert made significant contributions to calculus and mechanics, and his name is associated with the d'Alembert principle, which is fundamental in the study of dynamics. In addition to his mathematical achievements, d'Alembert was a prominent figure in the Enlightenment movement, advocating for reason and scientific inquiry. He also wrote essays on philosophy and music, showcasing his diverse interests. His legacy continues to influence various fields, making him a key figure in the history of science.