January 11

Born in 1688, Louis Bertrand Castel was a French Jesuit mathematician and philosopher of the early 18th century. He invented the 'ocular harpsichord,' a device intended to produce colors through musical harmonies. Castel wrote widely on geometry, optics, and the philosophy of science, challenging prevailing theories. His critiques of Newtonian optics sparked debates among his contemporaries. He explored the relationship between sensory perception and mathematical principles. Castel's interdisciplinary work influenced both scientific and artistic communities.

Born in 1704 in Aix-en-Provence, d'Argens served as a diplomat and courtier before turning to writing. His 1738 work 'Lettres juives' critiqued European customs through fictional correspondence, blending wit and philosophy. He became a close confidant of Frederick the Great and produced memoirs and satirical essays that challenged superstition and authoritarianism. His sharp observations and advocacy for religious tolerance made him a controversial yet influential figure. D'Argens' writings circulated widely, contributing to the intellectual ferment of the French Enlightenment.

Emanuel Lasker was born in 1868 in Berlin and became the second official World Chess Champion, holding the title from 1894 to 1921. Beyond his dominance on the chessboard, he earned a doctorate in mathematics and published works on algebra and game theory. Lasker explored philosophical questions about competition and human behavior in his writings. He defended his chess title against all major challengers, contributing to the development of modern chess strategy. After emigrating to the United States, he continued teaching mathematics at universities. His dual legacy in chess and academic scholarship endures to this day.