Étienne Gilson (13 June 1884 – 19 September 1978) was a Frenchphilosopher and historian of philosophy. A scholar of medieval philosophy, he originally specialised in the thought of Descartes, yet also philosophized in the tradition of Thomas Aquinas, although he did not consider himself either a neo-Scholastic or neo-Thomist philosopher. In 1946 he attained the distinction of being elected an "Immortal" (member) of the Académie française.
In 1913, while employed in teaching at the University of Lille, he defended his doctoral dissertation at the University of Paris on "Liberty in Descartes and Theology". His career was interrupted by the outbreak of World War I, as he was drafted into the army as a sergeant. He served on the front and took part in the battle of Verdun as second lieutenant. He was captured in February 1916 and spent two years in captivity. During this time he devoted himself to new areas of study, including the Russian language and St. Bonaventure. He was later awarded the Croix de Guerre for bravery in action.
In 1951, he relinquished his chair to Martial Gueroult at the Collège de France to devote himself completely to the Medieval Institute until 1968. He knew the Jesuit theologian and cardinal Henri de Lubac. Their correspondence has been published. Although de Lubac was primarily a historian of philosophy, he was also at the forefront of the 20th century revival of Thomism, along with Jacques Maritain. His work has received critical praise from Richard McKeon.
Gilson undertook to analyze Thomism from a historical perspective. To Gilson, Thomism is certainly not identical with Scholasticism in the pejorative sense, but indeed rather a revolt against it. Gilson considered the philosophy of his own era to be deteriorating into a science which would signal man's abdication of the right to judge and rule nature, man made a mere part of nature, which in turn would give the green light for the most reckless of social adventures to play havoc with human lives and institutions. Against "systems" of philosophy, Gilson was convinced that it was the revival of the philosophy of Thomas Aquinas that opens the way out of that danger zone.
In his time Gilson was the leading scholar of the history of medieval philosophy as well as a highly regarded philosopher in his own right. His works continue to be reprinted and studied today - perhaps alone among "Thomist" philosophers, his work and reputation have not suffered from the general decline of interest in and regard for medieval philosophy since the 1960s.