GAUNILONE. – Benedictine monk of Marmoutiers near Tours in the second half of the 11th century. He was the son of the viscount of Tours and, before entering the monastery, held the office of treasurer of the church of S. Martino of Tours.
According to annotations in several 12th-century manuscripts, he is the author of the Liber pro insipiente, which cleverly criticizes the Prologium of S. Anselmo. The Saint replied and wished the controversy, together with the chapters discussed (2–4), always to be appended to his work.
BIBL.: E. Martène, Histoire de Marmoutiers, ed. U. Chevalier, I. Tours 1874, p. 363; Opera s. Anselmo, ed. Fr. S. Schmitt, I. Edimburgo 1946, pp. 123–30.