The Speculum maius or "Greater Mirror" was a major encyclopedia of the Middle Ages written by Vincent of Beauvais in the 13th century. It was a great compendium of all knowledge of the time. The work seems to have consisted of three parts: the Speculum Naturale, Speculum Doctrinale and Speculum Historiale. However, all the printed editions include a fourth part, the Speculum Morale, added in the 14th century and mainly compiled from Thomas Aquinas, Stephen of Bourbon, and a few other contemporary writers. Source: Wikipedia (en)