Joseph Diaz Gergonne

Joseph Diez Gergonne (19 June 1771 – 4 May 1859) was a French mathematician and logician. Born in Nancy, France, he died in Montpellier, France. In 1791, Gergonne enlisted in the French army and saw action in the Battle of Valmy in 1792. He later transitioned to civilian life, taking up a chair in mathematics at the École centrale in Nîmes in 1795. Influenced by Gaspard Monge, Gergonne made significant contributions to projective geometry, particularly in elaborating the principle of duality. He also devised an elegant coordinate solution to the problem of Apollonius, demonstrating the power of analytical geometry. In 1810, he founded the Annales de mathématiques pures et appliquées, a journal that became a significant platform for mathematical research, especially in geometry. Gergonne's work also extended to the theory of definition, where he is credited with recognizing and naming the concept of implicit definition. He was appointed professor of astronomy at the University of Montpellier in 1816 and later became its Rector in 1830, ceasing publication of his journal at that time. He retired in 1844. Gergonne's legacy includes his pioneering work in optimal experimental design and his contributions to the foundational concepts of mathematics.